60 - 21475
U.S.S.R. LITERATURE ON AIR POLLUTION AND
RELATED OCCUPATIONAL DISEASES
VOLUME 3
A Survey by
B. S. Levine
Dept. of Commerce
Washington, D.C.
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60-21475
OUifT&tf
3
A SURVEY
by B. S. Isvine, Ph. D.
Distributed by „.
UNITED STATES DEPARTMENT OF COMMERCE
OFFICE OF TLCHNICAL SERVICES
WASHiHGTON 25, O.C
-------
SURVEY OP U. S. S. R. LITERATURE
OK AIR POLLUTION AKD
RELATED OCCUPATIONAL DISEASES
Volume 3.
Selected and prepared for photo-offsetting-
B. S. Levine, Ph. D*
U. S. Public Health Service
(Health, Education, and Welfare)
Research Grantee
Washington, D. C., U. S. A.
Submitted for publication May I960
-------
Other books and surveys dealing «r<*Vi U.S.S.R.
air pollution and related occupational diseases.
Sanitary Protection of Atmospheric Air,
Purification of Industrial Discharge
Gases from Suspended Substances - 59-21092
Limits of Allowable Concentrations of
Atmospheric Pollutants, Book 1 - 5^-21173
Limits of Allowable Concentrations of
Atmospheric Pollutants, Book 2 - 59-21174
Limits of Allowable Concentrations of
Atmospheric Pollutants, Book 3 - 59-21175
U.S.S.R. Literature on Air Pollution
and Related Occupational Diseases.
A Survey. Volume 1 - 6O-21049
U.S.S.R. Literature on Air Pollution
and Related Occupational Diseases,
A Survey. Volume 2 - 60-21188
Ruosiafl-Englioh Medical Dictionary.
By Stanley Jab Ion ski. Edited by
Ben 3. Levine* - Academic Press
-11-
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Foreword
Volume 3 of the Survey of U. S. 5. R. Literature' on Air Pollution and
Related Occupational Diseases represents a collection of $2 papers select-
ed by the undersigned from the following U. S. S, R. scientific p&rio'dicalsi
Gigiena i Epidendologiya (Hygiene and Epidemiology) of 19285 the publicat-
ion of this periodical has "been discontinued} Gigiena i Sanitariya (Hygiene
a#d Sanitation); papers were selected from issues of 1950, 1952, 1954* 1955,
1957 and 1958j Gigiena Truda i Professionallnye Zabolevaniya ''(labor Hygiene
and Occupational Diseases) the first volume of which appeared in 1957? tha
paper selected was published in volume 2, 1958i Lahoratornoe Delo (Laborat-
ory Research) of 1957 and 1958; Zhurnal Analiticheskoi KHimii (Journal of
Analytical Chemistry) of 1956; Zhurnal Prikladnoi KhiEdi (Journal of Applied
Chemistry) irf 1956; Koks i Khimiya (Coke and Chemistry) of 1956; Arkhiv Pat-
ologii (Archives of Pathology) of 1958; Izvestiya Akadendi JJauk S. S. S, R,
(Hews of the U. S. S. R. Academy of Sciences) of 1958; Doklady Vsesoyuznci
Ordena Lenina Aa-adendi Sel'sko-Khozyaistvennykh Hauk (Reports of the All-Uni-
on Order of Lenii. Academy of Agricultural Sciences) of 1957; and several
other pertinent j itrnals.
This, seemingly scattered selection is in line with the plan of the und-
ersigned to make each volume of the survey of interest to a wide scope of re-
search scientists on the one hand, and on tha other hand to enable environ-
mental health specilists in one narrow phase of their work to acquire some
knowledge of the results of research done in the 0. S. S. R. in other relat-
ed phases of the general field9 without having to sacrifice much of his or
her time devoted to their personal research. Organization of forthcoming vol-
umes covering the survey will follow this same basic plan*
B« S. La vine, Ph. D.
3312 Northampton Street, If, W.
Washington, 15, D. C«
3STote» Biy way of grateful acknowledgement each item in this collection is
headed by the original title (in translation), the name of the author or
authors, institutional affiliation and periodical or book from which item
was selected* The volume, issue number, year of publication and inclusive
pages are indicated for the convenience of those who may wieh to consult the
Russian original or make full reference to sam»*
B. S. Lavine.
-lit-
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Contenta.
Introduction
Section I. Analytical Methods and Procedures.
Determination of Air Dustinses According to Owens' Method*
B. A. Vigdorchik. 1
Determination of Tellurium Dioxide in the Air. G. V. Patrina. 13
Colorimetric Determination of Snail Quantities of Styrene in the
Air. M. I. Poletayev. 14
The Determination of Small Quantities of Fhthalic Anljydride in the
Air of Industrial Premises. L. 3, Chemodanova. 16
Determination of Mercury in Atmospheric Air. A. S. Aruin. 18
The Determination of Ozone in the Presence of Nitrogen Dioxide and
Hydrogen Peroxide. V. A. Shchirskaya. 20
Determination of Chlorinated Hydrocarbons in the Air "by the Method
of Micro-Combustion. D» P. Senderkhina. 23
Coloriaetric Determination of Lead in the Atmospheric Air.
V. A. Morozov. 2?
Determination of Active Chlorine in -the Air. H. G. Polezhaev. 29
fractional Determination of Hydrochloric Acid Aerosol and of Chlorides
in Atmospheric Air. H. V. Alekseyeva and £. V. Elfimova. 31
Determination of Dust in the Atmospheric Air with an Electrophoto-
colorimeter. B. V. Hykhter and IT. V. Shlygina. 33
A Chromathermographic Method for the Separation of Hydrogen, Carbon
Monoxide, Methane and a Mixture of Rare Gases. H. U, Turkel'taub,
0. V. Zolotarova, A. 6. Latukhova, A. I. Karymove. and Te. B. Eal'nina* 39
Quantitative Determination of Dichlorebenzene learners. A. A. Spryekov
and Tu. G. Erykalov. . 47.
A Method for the Determination of Phytoncides in the Air.
Tu. V. Ignatovioh and M. M. Epstein. 51
A Rapid Method for .the Determination of Kitrogen Oxidee in tbe Air.
L. A. Mokhov and V. S. Khalturin. 54
Simultaneous Determination of Carbon* Hydrogen and Bitrogen.
V. A. Klimova and G. F* Anismova. 57
Section II. Evaluations and Ccsaparative Studies.
A Hygienic Evaluation of Highly Dispersed Molybdenum Aerosol.
0. Ta. Uogllevskaya. 60
A Comparative Study of Experimental and Theoretical Atmospheric
Pollution Concentrations Resulting from Low Level Scissions.
P. I. Andreyev. 6*
-------
A Comparative Evaluation of Different Gravimetric Methods for the
Determination of Dust Concentration in the Air.
Te. V. Xhukhrina and Te. I. Voronteova. 70
A Comparative Study of the Retention Capacity of Different Filters
Used in the Gravimetric Determination of Smoke Suspended Aerosols.
E. V. Gernet 78
Sanitary-Technological Evaluation of Ash-Catching Systems Used in
U.S.S.B. Electrio Heat and Power Plants, Y6 Hs Uzhov. 87
Sanitary-Hygienic Evaluation of Industrial finissions by a Zinc-Lead
Combine. H. S. Pakhotina. 93
Section III. Hygienic Standardization (Limits of Allowable Concentrations).
Establishing Maximum Allowable Concentration of Hydrogen Sulfide in
Atmospheric Air. It. P. Glebova. 98
Determination of Sulfur Dioxide Odor Threshold Concentration.
I. N. Popov, Ye. P. Cherkasov and 0. L. Trakhtman. 102
The Stimulability of the Olfactory Analyzer in the Hygienic
Evaluation of Atmospheric Air Pollution* A. A. Xtskovich. 106
Experimental Determination of the Limit of Allowable Concentration
of Dichlorethane in Atmospheric Air. M. K. Borisova. 110
Determination of Limits of Allowable Concentration of Chlorine in
Atmospheric Air. If. T. Takhirov. 119
Hygienic Standardization of the Limits of Allowable Concentration
of Vapors of Gasoline in Atmospheric Air. N. P. Izmexov. 126
Maximum Permiesibls Concentration of Formaldehyde in Atmospheric
Air. V. P.* Melekhina. 135
Section IV. Sampling and Other Apparatus.
The Utilization of Air Dust and Smoke Purification Equipment.
V. C. Uatsak. 141
Efficiency of Mineral Wool Filters. T. S. Karacharov and
Te. I. Vorontsova. 150
Electrostatic Apparatus for the Collection of Atmospheric Dust
Samples. V. F. Idtvinov and H. H. Ldtvinova. 157
Method for the Collection of Samples of Air Dust with Particle
Diameters of Lea a Than 5 H- H. I. Smetanin. 161
Aspirators for Sampling Atmospheric Air Dust and Gases. L. F. Kachor 165
Adaptation of the Yu. A. Krotov Apparatus to Bacteriological Studies
of Atmospheric Air Under Field Conditions. H. N. Pokrovskii,
Ya. G. Eishko and A. P. Ostranitsa. 169
-------
3eo t ion V* Air Pollutants.
Atmospheric Air Pollution with Sulfur Dioxide from i»M-trtg Rook Dumps.
D. K. Kalyuahnyi, 3. A* Davydov, L. G. Dukarskaya and
M. *. Akeel'rod. 171
The Purification of Air Polluted by Vapors and Gases. V, G. Xatsak. 177
Zonal Study of Atmospheric Air Pollution In Areas Surrounding a
Roofing Tar Paper Plant. Ya. I. Shvarts and L. A. Zil'berg. 186
Acrolein as an Atmospheric Air Pollutant. It* 1C. Plotnikova. 188
Present Day Conditions of Atmospheric Air Pollution by Automobile
Exhaust Gases in Cities and Problems of Its Control.
M. K. ITedogibchenko. 195
Sulfurous Anhydride to the Atmospheric Air of Leningrad.
V. T. Lenshin. 2CO
Section VI. Toxicology and Pharmacology.
The Toxicity of Vapors of Organic Mercury Compounds (Ethylmercuric
Phosphate and Ethylsercuric Chloride) in Acute and Chronic
Intoxication. I. 1C* Trakhtenberg. 205
The Mechanism ^f Iron Ore Dust Action of Animals and Man.
Tu, I. Leonova. 211
Section VII. Microbiology.
Tho Study of Bacterial Air Pollution. V. A. Zubarev. 219
Studies of Airborne Microflora. V. V. Vlodavets. 221
Section VIIX. Conferences.
Three Conferences on Combatting Pollution of Atmospheric Air of
Inhabited Localities. A report* 225
Conference on Problems of IXast Catching. H. P. Pitelin. ~ 23O
All-Union Conference on Problems of Air Hygieno,
-------
Determination of Air Dustiness According to Owens* Method.
E. A, Vigdorchik.
From Leningrad Institute of Labor Hygiene and Safety Technique.
Gigiena i Epidemiologiya, No. 11, IO-19, 1928,
The term "Air Dustiness** has been applied generally to minute particles
of hard substances,suspended in the air for a considerable length of time.
Dustiness of air varies greatly, especially as regards the degree of particu-
late dispersion. The sizes of dust particles range from ultremicroscopic,
i.e., less then 0.3 p, which are in fact in co.loidal suspension, to aerosols
and to coarse particles of 100 n and larger; ths larger the diameter of the
air dust particles the more rapidly they will fell out of suspension. In prac-
tice, it is customary to classify these hard particles according to their so-
called diameters [1] as followss
Dust which consists of particles from 150 p. to 1 p in diameter; in in-
dustry these are formed principally during mechanical operations, such as
grinding, drilling or sharpening; vapors, which consist of particles from 0.2
to 1 jij these form in the process of distillation, complete or Incomplete oxi-
dation of metallic vapors and other chemical reactions; and smokes, which con-
sist cf part idee less than 0*3 p and are formed as the result of incomplete
combustion of hydrocarbons, coal, oils, tars, etc.
While the three classes of air participates serve certain practical ends,
actually there is no sharply defined boundary between the discrete classes
since siae of psrticulates is only one of many important characteristics of
air dust. Wells and Gerke measured the size of particles of tobacco smoke, by
a method based on the vibrations of the particles in an electrostatic field as
seen ultramicroseopically; they found that the average diameter of tobacco
emoke particles equalled 2.73 z 10 , i.e., 0.27 H« These authors passed duet
of red lead through, a dust chamber which included a number of settling tanks,
and found that the diut' contained a large number of particles 0.3 p in diameter.
It is obvious that even though the diameter of the two types -of particu-
latee were practically identical with reference to rate of sedimentation and
in some other reapeots, the dust particles of red le&d will behave in a manner
._ -1-
-------
somewhat different from the particles of tobacco omoke. This merely means that
in the classification of dusty their origins, their physical and chemical prop-
erties, and other factors must be tafrrn into consideration*
Many methods exist for the determination of the concentration of dust par-
ticles aleo suspended in the air, but no one method can be specifically selected
ao the best or most reliable. Instead of enumerating all the methods, only tho
main principles upon which these methods are based will be mentioned:
1. Filtration method* A specified volume of air is passed through a solid
filter or an absorber solution, and the retained dust is weighed*
2. Tha plate sedimentation method.
3* The contact method* A current of air is directed against a plate
coated with oil, vaseline or glycerin, as in a koncsneter.
4. The condensation method, based on the condensation of water vapor on
particles of dust in the atmosphere, which it subjected to sudu^n rarefication,
as in the Aitk?n and Owens apparatus.
5. The electric sedimentation methods by means of high voltage electric
currents* , . •
6« Photometric methods. Tyndalmeter or Tolmann's, Rich's device, Kali-
tin's phot ©element method, and nephelometry*
7. UltramJ.croscopy .
Some of the methods yield results in absolute figures, that is, "by woight
or count per specific volume of air, while the results of other methods, such
as the method for sedimentation on plates and the photometric methods, aro rel-
ative. - The basic distinction between these methods is the approach to the de-
termination of the concentration. Some of the methods determine the conoantra-
tlon by the weight of participate substances in a specified volume of air,
while other methods determine the number of particles in a specified volume of
air. There are some combination methods which present simultaneously the weight
and Vne count of the particles and, at tires, their dimensions. They usually
include certain filtration methods and electric dust sedimentation.
In practical sanitary inspection of manufacturing plants the filtration-
weight method has been used principally, also the methods of eedimentation-
count on plates, described "by Khokhryakov [3]. -The question arises: Bo these
methods satisfy all needs? Unfortunately, the method of weight by itself is
far from satisfactory, and such findings as "20 mg of dust per cubic meter of
-2-
-------
air* art not explanatory, since It has no reference to the actual dustiness of
the air. The 20 rag per m in the spinning section of a rope factor/ portrays
a picvurw c* dense dustiness, while 20 mg per m of lead dust is almost trans-
parent air. Ctee particle of lead dust 100 ** in diameter weighs as each as
125,000 particles of the sam« duat 2 p in diameter [4]* Hence, a knowledge
of tho weight of the particles in the air without knowing their number and
dimensions, offers no basis for the determination of the actual dustinese of
the air.
Havrogordatoy Collis, Haldane, Gardner, Willis, Brtnker, Jotlen, Arnold!,
and others studied the effect of dust upon organisms, particularly on the
lungs; they took into consideration not only the amount of dust but also the
results of experimental determination of such closely related factors as the
dimensions of the dust particles, and thoir physical and chemical properties.
Havrogordato, one of the coat outstanding English investigators in this field
devoted nearly ten years to this study; he refuted the generally accepted hy-
pothesis of an irritating action by the sharp edges of dust particles [33* He
expressed the opinion that the sharpness of particles 1 \i in diameter is an
ephemeral notion. The same author had established that the most dangerous par-
ticles of silica dust are those ranging in sizes from 0.5 (t to 5 £ C^3* Thus,
this field of air sanitation presents a series of problems none of which can
ba resolved by the weight method alone.
The plate sedimentation method furnishes information concerning the rela-
tive number of particles and their shapes and sizes; unfortunately the volume
of air from which these particles were deposited is unknown. However, there
is a device, the so-called ^counter of settling dust [particles]" [?]» with
the aid of which it is possible to know the volume of air from which a given
amount of dust was deposited on the cover glass; but here again? the study
would be confined to the coarser and heavier particles. It is unlikely that
tlieee cover glasses would reveal the exact picture of the particles suspended
in the air* The method can be used in a study of settling particles of duet,
but will offer no information regarding suspended dust at a given moment. Con-
sequsntly, up to the present no satisfactory methods have been available for
the complete study of the particles suspended, in the air. The best method is
a combination method which makes possible the determination of weight, count,
and particle dimensions, such for instance as certain filtration methods, the
-3-
-------
sugar tube and the Palmer apparatus [8], However, these methods can not he
used in the analysis of certain aerosols, soluble organic and inorganic dusts,
etc. Even duet, which ia studied with the aid of a microscope, has changed,
Among the tetter methods which make possible the completion of dust analy-
ses within one or several minutes ares Altken apparatus, Owens apparatus and
Kats konometer. The first two are based on the principle of condensation, and
the.konometer is "based on the contact principle* The Aitken apparatus affords
rp possibility for dimension determination, but gives the number of particles
per unit of air volume. The apparatus of Owens and Eats give the number of
particles per one cubic centimeter of air, and there is a possibility for si-
multaneous determination of particle size and shape. The Owens method was
tested in the Institute of Labor Hygiene and Safety Technique in order to de-
termine its possible use in routine sanitary inspection for the determination
of air dustinesa in manufacturing plants. The Owens method became popular in
England and America. It is sufficient to mention that this method is recom-
mended by one of the best dust laboratories in America [9j as well as by mete-
orologists [10 and ll^. In the U.S.S.R. this method was recommended by Grod-
zovskii [12] in 1928; however, until now no mention has been made in the Russian
literature of air dust determinations made by this method*
During the testing of Owens method at the Institute of Labor Hygiene and
Safety Technique, no effort was made to ascertain whether 100£ of the particu-
late matter was accounted for by the device, i.e., including particles which
ranged in size from ultramioroscopic to those of largest diameters. In this
connection it must be borne in mind that particles of less than 0.3 n in diam-
eter can not be counted by the ordinary microscope because they are beyond the
resolving power of any ordinary microscope. Furthermore, by the very nature of
the apparatus each count method yields its own specific results which can not
be interpreted in terms comparable with results of other methods. In this re-
spect the works of Kats, Smith and layers [8] are of particular interest. They
determined the number of dust particles per cutic centimeter of air simultane-
ously with the aid of the Kate konometer, the Palmer apparatus, the sugar tube
aM the Impinger apparatus. As a result of their extensive work tlioy concluded
that no absolute method existed for the determination of air dust concentration
»
expressed as numbers of particles per unit air volume, and that comparative
evaluations were merely relative measurements of each method's efficiency.
-------
Each apparatus gave its own data so regularly that the authors were able to
derive an equation for the conversion of the results of one instrument to
another, using different constants for different kinds of dusts*
The method of Owens was tested with a view to its possible practical ap-
plication) the testing consisted in checking possible errors in count in the
microscopic counts, checking the precision of repeated readings under identical
conditions, and checking on its possible use for different kinds and concentra-
tions of dust under actual manufacturing conditions. The apparatus operates
through a small air pump with a capacity of 50 cm which aspirates air at a
high rate of speed over a microscope cover glass. The air is prehumidified
and, entering into a partial vacuum, is subjected to sudden expansion. This
forces the moisture to settle on the dust particles and causes them to adhere
to the cover glass making possible their microscopic study. The apparatus can
be taken apart for cleaning and reassembly. (See Fig l).
The small copper sleeve B is open at the top
and at the bottom. Part K, which ia screwed into
tue lower opening, has a narrow slit A, formed by
two semicircular plastic plates, which is 0.1 mm
wide, 10 mm long and serves as an air passage. The
cover glass is placed over the slit at a distance
of 1 mm, forming a chamber 10 mm in diameter and
1 ran deep. The cover glass is carefully held in
space by means of a plug C which is equipped with
a triple toggle spring. Pump P is screwed into
sleeve B, at opening E, which connects it with the
space between C and K. The air drawn by the pump
passes through slit A, strikes the cover glass,
and flows through special channels H toward the
pump. The pump is equipped with a one-way control
valvej during the reverse piston stroke the air is prevented from entering into
the space between C and K, and is expelled outside. A humidifying chamber T,
screwed in to part K, is lined with moistened filter paper. Whan air samples
are collected the plug is in, and without the cover glass, the air is made to
pass three or four times throu^i the slit in order to fill the humidifying
chamber with the air to be analyzed. The plug is removed, the cover glass
^^^^^Jj^^fr'^^^^lM^M
1.
-5-
-------
placed in position and fastened down by replacing the plug, all in rapid suc-
cession; the pump piston is pulled forcefully once or repeatedly, depending
on the desired volume of air. There should be a waiting period of not less
than 15 seconds between the successive piston strokes in order that the air
within the humidifying chamber can become sufficiently humidified. After the
air sample has been obtained, the plug is taken out and the covar glass placed
on the palm of the hand. It is then placed on a microscope slide for micro-
scopic examination*
In preparing the sample for microscopic examination it is essential that
the dust collected or tha cover glass should not come in contact with any other
medium. Owens i
-------
Pig. 3.
The procedure is as follows: Using low magnification the number of cross
rows of squares of the eye-piece micrometer is counted over the entire length
of the dust strip, beginning at one end of the strip and moving up or down, as
the case may be, toward the other end. Assume that there were 140 transverse
rows. If the immersion system used was of 10 X magnification, then the number
of rows with such immersion magnification will be 1,400. Hext, count the num-
ber of particles within a single transverse row from the several rows selected
in different sections of the preparation and compute the average number of
dust particles per row. Assume that the average number of particles per one
cross row was 200 and that 400 cc of air has passed over the slit-strip, thent
(200 x 1400)/100 - 2800 dust particles per cc of air.
Lett S - the total number of cross rows over the entire length of the dust
strip}
H • the number of particles ia one cross rowj
C - the number of cc of aspirated
then, the number of particles per cc of air
KS
with the same system of mag*-
nification and the same volume of air 77 remains constant within the limits of
V
given concentrations.
An important and valuable characteristic of the Owens method is the pos-
sibility of determining not only the number of partlclea but also the degree
of their dispersion. Furthermore, with the aid of an eyepiece-micrometer or
still better, with the "Schraubenmicrometer" it is possible to make a differ-
ential particle count. The preparation can be stored for a long time.
Checking the precision of the method is very intricate under manufactur-
-7-
-------
ing plant conditions, since the concentration and composition of the particu-
lates suspended in the air constantly vary* Therefore, it is necessary to
create a uniform dust suspension experimentally. In this respect this author
was working under very favorable conditions because the Institute of Labor
Hygiene possessed a dust chamber which could be filled with dust-laden air of
a wide range of concentrations and kept unchanged for a time [13]. Count er-
rors and the precision of the instrument under identical conditions were
checked in this dust camera. Two series of experiments were aade for check-
ing the count errors
1. Two samples of red lead air dust having respective concentrations of
7,335 and 119149 per oc were subjected to 20 separate counts on different days
and under different conditions of illumination. The results of the counts are
shown in Table 1.
Table 1
Seoond preparation
Number of
particles
per oo
11.235
11.713
•11.072
11.103
11.801
11.183
11.129
11.110
10.976
First prepraration
Count
Ho.
i.
2.
3.
4.
5-
6. .
7.
8.
9,
10.
11.
17.
13.
14.
15.
16.
17.
.18.
19.
20.
Number of.
particles
per oa
7.182
7.081
7.313
7.325
7.498
7.344
7.923
7.241
7.500 ...
7.392
7.196
7.295
7.491
7.306
7.320
7.208
7.322
7.213
7.064
7.560
Count
Ho,
2.
1.
3.
4.
K
6.
7.
8.
9.
10.
11,
12.
13.
14.
15.
16.
17.
18.
19.
20.
Average
7.335
11.102
10.868
11.174
11.045
10-981
11.057
11.009
11.035
10.870
11.141
Average n.149
Statistical analysis of the results gave variation coefficients of 2-5?
and 2.15% respectively, for the first and the second preparations.
-8-
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Table 2.
Dust particles per co
Test
Ho*
j.
2
3.
4
5*.
K
* J *
1
8.
9.
in
» ".
H.
12.
13.
14.
15.
1«.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
First
count
5.958
3.555
il.808
10.170
3.978
5.733
2- 781
7.947
9.423
9.fl21
6.426
8-361
5.637
5.472
10.299
9.153
3.168
5-445
3.186
2.250
2.961
4.275
3.069
2.286
3.3ft6
1.071
4. 905
5.751
2.412
7.812
657
765
2.799
12.564
6.345
Second
count
6.048
3.789
11.178
10.233
4.473
5.472
2.754
8.100
9.306
10.692
8:567
7.614
5.544
5.995
10.305
8.784
3.150
5.391
3-051
2.124
2.826
4.464
3.159
2.142
3.753
1.035
5.211
5.607
2,664
7.694
684
774
2.664
12.105
6.372
Difference
d V*
in %
1,5
6,2
5,3
0,5
11,1
4,5
0.9
1,9
1,2
10,0
6,4
8,9
2,7
7,3
0,0
4.0
6,5
0,9
4,5
5,6
4,5
4,2
2,8
6,3
10,0
3,3
5,8
2,5
9,4
1,4
4,2
i.2
4,8
3.3
0,6
Average 4,23
Test
No.
1.
2
* •
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15-
16.
17.
18.-
19.
20..
Number of
First
count
6.291
6.570
4.509
2.853
2.124
8.796
5.553
1.521
4.680
2.070
2.034
664
2.268
1.854
2.736
1.116
1.953
5.967
4.761
4.040
Table 3.
dust particles
Second
count
6.651
6.651
4.518
2.628
2.115
8.469
4.797
1.449
4.851
2.142
2.068
900
2.259
2.065
2.817
1.204
1.944
6.020
4.554
4.040
Difference
in %
6,0
1.6
S'2
n>!
S'4,
3,8
12,0
4,8
3.5
3,3
2,6
4,0
°'!
n.e —
2.8
H
0.5
0,9
4,3
0.0
3,8
2. Thirty-five dust samples of
red lead air dust with concentrations
ranging from 11,808 to 657 dust parti-
cles per cc wore sucked into the dust
chamber, and each preparation counted
twice* The average percent variation
between separate counts was 4.23$, as
shown in Table 2.
Thus the limits of the count error
were determined. It was now possible
to check the precision of the instrument
under identical conditions. Twenty se-
ries of tests were made as follows: two
air dust samples were drawn in one minute
apart into the dust chamber from the same
place and by the same device; the dust
concentrations of the 20 air samples
varied from 8,796 to 864 dust particles
per cc. The results are listed in Table
3.
The data in Table 3 show that all
differences between the counts of each
pair of teats stayed within the limits
of experimental error.
The apparatus was then tested with
the following types of dusts 1. coal;
2, cement; 3. wood; 4. cotton; 5. hemp;
6. graphite; 7* dust from a buffing ma-
chine; 8. street dust; 9. lead dustj 10.
blacksmith shop smoke.
Similar check tests including par-
ticle size determinations were then made
under practical conditions directly in
manufacturing plants. The results are
listed in Table 4.
-9-
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Table 4.
Uumber and size of dust particles beginning with 0,3
Counted by the method of Oaene
Particle sizes in percent
Cement plant
Dust
prtols. a «.
per oo - "?
V J.
C T
3L
8
£L
IA
Remains
1
2
3
"Kanat" plant
4
5 a
b
6 a
b
Curtain weaving
7
A
V
9
10
B
3.514
2.030
31.988
1.551
990
876
536
1.108
561
449
441
2.760
11.0.1
1.610.
40,3 52,0 5,7
20,0 74,0 5,0
99,0 1,0 — .
25,3 66,5 5,4
50,0 43.0 4,6
48,8 47.95 2,0
93,8 6,2 —
94,6 5,4 —
72.0 21,75 4,6
84.0 12,0 4,0
83,0 15,0 2,0
97,8 2,2 —
92,0 8,0 —
93,2 6,8 —
0,8 0,4 0,4 0,4
1,0
2,2 — 0,0 —
1,1 0,4 0,4 0,2
0,8 0,2 0,15 —
__ — — —
— — ~~~.
1.5 - — 0,5
— • — — —
"
— — — —
— — — —
1 - Fuel (ooal) section near ball mills; 2 - Cement section near
clinkers} 3 — Smithy with poor ventilation* 4 - Bast fiber comb-
ing; 5 - Send automatic spinning (a) low grade fibers, (b) better*
grade) 6 -Tweaking of tarred bast fibers (a) slow process, (b)
fast process; 7 - Weaving department, close to machines, graphs
ite powederingj 8-2-3 metera away; 9 - Ditto, in another
section; 10 - Smithy, good ventilation in dust chamber; 11 -Lead
oxide (red lead) duet, 5.7; 12 - Ditto, 17.V
(*) Dense preparation, difficult to count? (**) Through exhaust
ventilation in operation*
The above results show that the described method, including determination
of particle sizes, presents with high accuracy the characteristics of the air
suspended dust, since the number of particles and their sizes give more de-
tailed and accurate information than th*9 gravimetric method. The advantages
of this method are the short sampling timo and rapid analysis of the dynamics
of the dust-laden.air.
-10-
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90
M
T»
•0
'50
«0
30
to
It
Street dust
3/5, 1928
368 particles per oo
/WO
•0
70
£0
M
<•
M
»
10
(2,760 particles per oo
Size in p
•Diagram 1
A
Lead oxide dust "
in dust chamber «
(8,720 particles per oc *\
i-t 1-10 M-U ti-u ten tt-u M-JI
Siae in p
Diagram 3
£t 1 '-* l't> •*•"* '*
Size in p
Diagram 2
Curtain weaving machine
f
* —^— At the machine
561 particles
Two meters away
449 particles
t-m »-a
Size in p
Diagram 4
tlooo
now
now
CD
(4 1000
03 anoo
P« 7000
ID S090
to
II
n>
to
machine •
good exhaust ventilation
425 particles per cc
Size in
Diagrata
O ~ .M . i" "* *° *•
j2- Time in minutes
Diagram 7.
Changes in lead oxide dust
concentration
rtKAHAT" (Rope) plant
SlS^ - 53
— Spinning -
°C
er cc
^,er cc
96 per cc
Size in p
Diagram 6
Tf!
Fig* 7 is a plot of changes in the number
of particles in the dust chamber during the op-
eration of the shaking machine used to control
dust concentrations in the chamber. Of special
note is the fact that while the dust count had
fallen from 12,697 to 1,800 dust particles within
one hour, the gravimetric method gave 46 mg per
m for the same period of timoe
The work herein reported on was done with
the aid of Owens apparatus manufactured V the
-11-
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Casella Company of London; it bore a certificate from the Advisory Committee
on Atmospheric Pollution, Air Ministry, Meteorological Office in London. This
original apparatus was reproduced in Leningrad; the latest perfected model re-
cords readings identical with the original.
On the "basis of tests to which Owens apparatus was subjected in the dust
chamber and under manufacturing plant conditions, it can be stated that the
method and apparatus present a considerable advance in the problem of dust
study. Particularly valuable characteristics of the instrument arei
a. Particles suspended in the air measuring 0.3 p and above in diameter
can be reliably counted;
b. Differential particle counts can be made simultaneouslyj
c. The dusts studied microscopically remain unchanged because of the
special method used in making the preparations;
d. Differences in duplicate readings do not exceed the limits of experi-
mental error;
«, Sample collecting is not time consuming;
f. As a consequence to the rapidity of sampling, the dynamics of the
dust-laden air can be studied reliably;
g» The apparatus is of small size and is easily portable.
Bibliography.
JlHTeparypa. i) G I b h s — Clouds and Smokus. London, 1924. 2) Wells and.
Oerke — An oscillation Method loTTHe'asuring the site of ultramicroscopie Par tic las Jour-
nal of American Chem. Soc. 41,312,1919. 3) XoxpflKOB—MexonHira • mncpocttHUHecHtx
a MHKpoxBHHHeCKHx onpe^ejieEinfi cocTasa DUJIH B apomaaastttasx. npe«np»irTHHX, Tpyw
HaytHo-HccjieAOBarcjihCKOtt CBKUHH JleeHHrpoACKOro TOTs. 1927 P. 4) Hope. Hajmauand,
StaUvbressJtodi stria! Hygiene and Medecine 1923. 3) MavroMrdaUL^ umtrfbution lo
the Study of Mioer's Phtisis. So Afr. Inst. Mcd. Res. Pub. JV? 12 Johannesboufg Dec.
1926. 6) £Iaaafigoo!atP — The Value/of the .Kommeter So Air. Inst. Med. Res. Pub; M 17
Johannesburg Aug. 1923, >)Middleton — !)enst in Cotton Card Rooms The Jouro, of Ind.
Hyg., 1926. A> It. 8) Kotz Snythl MaiaBS Po(- rmination of Air Duatiness with the Sugar
Tube Palmer. Apparatus andimpigner compared with Determination of the Konimeter.
Journ. of Ind. Hyg. M 5, 192G..?) Dnnk^r, Thomson. The Use of Ovens Jet Pu*t Con-.
nter and of Electric Prccepitation in tnepere r ml naTion of Dust Fumes ana Smokes Journ.
of Americ. Chamic. Son. of Heal and Vent, Eng. AS 11, 1924. 10} Herbert. H. KimbalL
and Jrsing Hang Investigation of the Dust Content of the Atmospher «Monthly Weainer
Revie^7»='Junii925, J^6/13, 53. It) Boytan —Atmosphere DustamtCondensalion Nuclei
Proccediog of UIR Roy.aF Irisch Academy Vol. XXXV11 Section A, M.6. September
1926. 12) rpoa^OBCHnB, AHOJIHS oonayxa « npOMbnnacHHiix npeanpHnTHnx. 1925 r. 13) He-.
-12-
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Determination of Tellurium Dioxide In the Air.
By
0. V. Patrlna.
Gigiena i Sanitariya, No. 3, p. 46, 1952.
A colorimetric method was developed for the determination of tellurium
dioxide in the air, "based on the following principles in reducing tetravalent
tellurium salts to elementary tellurium with stannous chloride iz* hydrochloric
acid the color of the solution changes to light or dark brown* By comparing
the color intensity of the test sample with a standard set of colors the amount
of tellurium dioxide can be determined*
The following reagents are used in this procedure:
1. 20# stannous chloride solution (SnClg.aHgO) prepared by dissolving
200 g of stannous chloride in 1 liter 1*3 solution of hydrochloric acid.
2* Standard solution of tellurium dioxide containing 0*1 ? (no designa-
tion in original text) tellurous anhydride in 1 ml. To prepare it dissolve
1*0799 g of chemically pure powdered tellurium in STJO, in a porcelain dish by
adding the acid to the powder gradually until violent reaction ceases, then
add 5 - 10 ml more of the acid and evaporate to dryness* Redissolve in Itl
solution of HC1 with the aid of heat and pour into a 1 liter volumetric flaskj
fill to mark with water.
3. Hydrochloric acid solution 1x1.
4. Hydrochloric acid solution 1:3.
5. Hitrio acid solution 111.
Collection of P*T» flftnrnla- Depending upon the anticipated concentration
of the tellurium dioxide in the air aspirate from 50 to 100 li of the air
through a flanged tube at the rate of 10 li per minute, fill the tubo with
glass wool soaked with 111 solution of nitric acid.
Analytical procedure. Remove the glass wool from the tube into'a glass
beaker and wash with nitric acid followed by hot water until the acid reaction
disappears. Evaporate content to dryness and dissolve the residue in 5 - 10 ol
of lil hydrochloric acidj boil for not longer than 5 minutesj prolonged boiling
results in a loss of tellurium. Filter 5 ml and to the filtrate add 5 ml of
distilled water; mix well; add 0.2 ml of the stannous chloride solution and
shake well. Prepare the standard color scale as followsi Set up a series of
-13-
-------
test tubes) add nothing to the first, or control, tube; to the other tubes add
successively 0.1, 0.2, 0.3, 0.4, 0.5> 0.6, 0.7, 0.8, 0.9 and 1.0 ml of the
standard solution; add to all tubes 2 ml of Isl HC1, then add H-0 to all tubes
to the 10 ml mark; mix and leave rest until a brown color develops. Compare
colorimetrically.
Calculation of results. Follow the usual analytical procedure used in
colorimetric method and determine the tellurium dioxide contained in the total
volume of the absorber solution. Knowing the total volume of aspirated air
calculate tellurium dioxide concentration in the air.
Using this method it was found that the concentration of tellurium di-
oxide in foundry air at the inhalation level ranged between 0.0019 and 0.006
roe/li.
Colorimetric Determination of Small Quantities of Styrene in the Air.
M. I. Poletayev.
From the Institute of Labor Hygiene and Occupational Diseases of the
Academy of Medical Sciences of the U.S.S.H.
The wide use by different industries of compounds of benzene and of un-
satu rated hydrocarbons made imperative the study of the sanitary-hygienic la-
bor conditions in workrooms of pertinent production plants. Styrene is one of
the benzene compounds which has recently become widely used in industry; it is
produced by substituting one hydrogen atom in benzene by an ethylene radical.
Styrol, CgHe-CH-CHg, is a colorless liquid having a characteristic persistent
1 odor. Its- boiling point is 146° and specific gravity 0.907. This substance
is also known as vinyl benzene end as phenyl ethylene. According to literature
styrene vapor has strong 'irritating and narcotic properties; it affects the
hematopoietic system. The continued interest in this substance is due to the
-14-
-------
fact that polystyrene, a product of styrene polymerization, is rapidly finding
application in broadly expanding tranches of industrial production.
The determination of small quantities of styrene as described in litera-
ture ia based on Its nitration property and is made photocolorimetrically.
Styrene is absorbed from the air into a special ice-cooled glass absorber con-
taining carbon tetraohloride. The absorbed styrene is then nitrated with a
mixture of sulfuric and nitric acids and the nitrated product isolated. This
method was tested in the laboratory and found Impractical for the following
reasons: the use of a volatile liquid absorber, such as carbon tetrachloride
required ice-chilling and a special type of styrene glass absorber which com-
plicated the analysis; the 0.1 mg sensitivity of this method was not adequate;
in using carbon tetrachloride as the liquid absorber the air had to be aspi-
rated through the absorber at a low rate such as 10 li/hour, which prolonged
the determination time; aspirating the air through two ice-chilled absorbers
at a rate of 10 li/hour caused a considerable evaporation of the carbon tetra-
chloride in the first and second absorbers. An experimental attempt was made
to absorb styrene directly into the A. V. Stepanov nitrating mixture, prepared
by dissolving 10 g of ammonium nitrate in 100 ml of sulfuric acid of 1.84 sp.
gr. 1 - 2 ml of this mixture were poured into small Polezhaev absorbers. Ab-
sorption was made from a special bottle, the air of which was saturated with
styrene vapor, by aspirating the test air through two absorbers connected in
succession. Nitrated styreno vapor acquired a yellow color; the nitrated prod-
uct was completely retained in the first absorber even when the air was aspi-
rated at a rate of 1 11/min.
It was noted that during the absorption of styrene from the air directly .
into the nitrating mixture the yellow color acquired by the solution was not
permanent. To prevent the yellow color from fading it was necessary to change
the medium as follows: after styrene vapors were absorbed from the air the
content of the absorber was diluted with 3 ml of distilled water and neutralized
by a 25$ ammonia solution until litmus paper showed an alkaline reaction. This
produced a stronger and more stable color. Caustic alkali solutions as neu-
tral izers proved Inapplicable because the formation of a nitrate precipitate
interfered with the determination. Final colors were compared with colors
yielded by standard styrene solutions In carbon tetrachloride.
The standard scale ia prepared by setting up a series of colorimetrio
-15-
-------
tubes containing equal volumes of CC1. and preparing a atyrene stock solution
containing 5 mg of styrene per 1 ml of CC1,. No standard solution is added to
the first or control tube; 0,001 ml, or 0.003 mg IB added to the second tubej
0.002 ml, or 0.010 mg to the third tubej 0.003 ml, or 0.013 mg to the fourth
tube; 0.004 nil, or 0.020 mg to the fifth tube, etc. The method was tested
under factory working conditions. The simultaneous presence of benzene and
ethyl benzene with styrene in some technological processes did not interfere
with the determination. Dinyl (diphenyl and diphenyl oxide mixture), used in
the production of insulating cut sheet polystyrene for heat conveying, in 0.2
mg concentration did not interfere with styrene determination* In concentra-
tions above 0.2 mg dlnyl produced a yellow color and turbidity.
The Determination of Small Quantities of Phthalic Anhydride in the Air of
Industrial Premises.
L. S. Chemodanova.
Institute of Labor Hygiene and Occupational Diseases of the
Academy of Sciences, U.S.S.R*
..... Gigiena i Sanitariya, No. 4, 48-49 9 1952.
Phthalic anhydride is of great technical Importance; it is used in the
synthesis of many dyes and in the manufacture of some plastics. The problem
of its effect on the human organism has not been studied much. It is known
that intimace contact with it caused strong irritation of the nasal mucous
membrane, that it produced dermatitis and sometimes resulted in the loss of
hair. Fhthalio anhydride has also a generally toxic effect. The molecular
weight of phthalic anhydride is 148.03, specific gravity 1.527» melting point
128 - 131°, and boiling point 285°. Fhthalio anhydride is soluble in hot water,
alcohol, ether, benzene, chloroform, and bdgins to sublimate below the melting
point* Snail quantities of phthalic anhydride have been determined by its
-16-
-------
following properties! l) sublimation with heat; 2) fluorescein formation in
fusing with resorcin, and 3) formation of phthalate.
This writer used the fluorescein formation reaction for the quantitative
determination of phthalic anhydride in the air of industrial premises. The
reaction can he presented as follows t
0 + 2CSH4(OH), -^CO C O
^ O / XC,H,/(OH)
The following reagents were ueedi
1. A standard solution containing 2 mg of phthalic anhydride in 1 ml of
alcohol. One ml of 1:10 dilution of the standard contains 0.2 mg of phthalic
anhydride;
2. A freshly prepared resorcin solution in sulfuric acid, obtained by
dissolving 0*2 g of resorcin in 20 ml of sulfuric acid of 1.82 - 1.84 sp. gr.,
heated over a waterbath and thoroughly stirred with a glass rod until the crys-
tals completely dissolved. The final solution is of a golden-yellow color;
3. 0.1 H sodium hydroxide solution;
4* 25£ ammonia solution;
5* 35# sodium or potassium hydroxide solution.
A known volume of the standard phthalic anhydride solution was placed into
a round-bottom test tube 15 - 16 mm in diameter and 125 - 130 mm high; alcohol
was added up to 10 ml followed by the addition of 1 ml 0.1 N NaOH or KOH solu-
tion and the content evaporated over a waterbath. One ml of concentrated sul-
furic acid was added to the dry residue and the content heated over a boiling
waterbath until the substance completely dissolved. Then one ml of resorcin
is placed into the test tube, and the mixture heated again for 10 minutes over
a glycerine bath at 170 - 180°.
The fluorescein obtained after the condensation is washed off with water
into a cylinder and 2$% ammonia solution ia added from a burst-to to weak alka-
line reaction. Water is added up to the 30 ml mark.
Colorimetrio determinations are made with 3 nil of the solution in colori-
metrio tubes.
A standard fluorescein scale is prepared containing 0.05, 0.25» 0.35»
0.45 1 0.^0 and 0.75 Q£ of phthalic anhydride in a successive series of colori-
metrio tubes. Colorimetrio determinations are made at daylight or in the
-17-
-------
light of a mercury-quarta lamp; the control tube, containing no phthalic an-
hydride, is of a light blue color, and with it the color was green. The color
increased with the increase in the phthalio anhydride concentration. The
scale colors will keep for a long time.
Absorption of phthalic anhydride from the air was tested with absorbent
cotton, glass "wool", filter paper, and porous glass discs. Best results were
obtained with ash-free filter paper.
Good results in phthalio anhydride absorption were also obtained by using
funnels with porous glass discs.
The elution of the phthalic anhydride from the porous discs was attained
by passing through the discs 10 ml of ethyl alcohol twice*
With high concentrations of phthalic anhydride in the air it is possible
to collect samples into vacuum glass containers of 1 - 2 li capacity; the
phthalic anhydride condenses on the walls of the aspirator and must be washed
off aith 15 - 20 ml of alcohol.
The deaorbed phthalic anhydride is converted to fluorescein as previously
described in connection with the preparation of the standard scale.
Determination of Mercury in Atmospheric Air.
A. S. Aruin.
From Erisman's Sanitary Scientific Research Institute*
Gigiena i Sanitariya, Ho. 5> P« 46, 1954*
Determination of mercury in atmospheric air by the B. G. Polezhaev method
presents some difficulties. First, a rapid vaporization and blowing out of
iodine from curved capillary tubes containing the iodine crystals takes placa
during the collection of air samples; second, the collection of air samples
is tijae—consuming, and third, the instability of sodium siilfite of the absorber
solution introduces errors into the determination of mercury. Hence the at-
-18-
-------
tempts to develop a tetter method*
The recent method, of M. A. Petrova is based on the reaction between mer-
cury ions and Reyneke salt which produces an acid insoluble amorphous sediment
having the following formulat NH.[(CHS).Cr(NH.)2]. This reagent is practi-
cally specific, since, in addition to mercury, only gold, silver and thallium
precipitate in an acid medium. Eeyneke salt has been utilized by many authors
for the determination of mercury by the gravimetric and nephelometric methods*
The photometric method of M. A. Petrova is sensitive to 0*5 Y in 10 ml.
The data presented by Petrova indicate that 0.5 Y caused galvanometrio deflec-
tion of 1.4 division and a relative error of 36£. This reaction was utilized
in developing a visual method for the determination of mercury in small volume
samples; tests were made of the sensitivity of this modification, and attempts
were made to develop a technique for the collection of air samples using Pet-
rova's absorber solution which consists of 700 ml of 0.527? solution of potas-
sium permanganate and 300 ml of 3.4 "$ solution of nitric acid* Air samples
were aspirated through Bykhter glass absorbers. Preliminary control determi-
nations were made as follows: a weighed quantity of metallic mercury was
placed into special type of glass container which was connected with two Byfchter
absorbers each containing 1 ml of the absorber solution. The mercury was
heated and the air was drawn through the entire set-up at different rates of
aspiration. Results of the preliminary tests showed that at air aspiration
rate of 5 li/min an average of 4% of mercury passed over to the second absorber
when the initial Eg condensation was 0*33 ~ 0*41 Y/H* Tte mercury was com-
pletely absorbed by the solution in the first absorber* when its initial con-
centration in the air measured in hundredths of Y/H- I* is suggested that
cotton filter be inserted into the intake part of the aspirator to prevent
dust from being sucked into the absorber solution. Control tests showed that
no mercury vapor was retained by the cotton filter even in tests made with $00
to 2,500 Y o£ mercury*
Mercury determinations in atmospheric air were carried out as follows!
Air samples were collected by aspiration rate of 5 li/min through two small
Bykhter absorbers, each containing 1 ml of the absorber solution. Cotton fil-
ters were placed in front of the absorbers. After the air samples were col-
lected 0.1 ml 1 N oxalic acid was poured into each absorber to discolor the
permanganate* The absorbers were then connected to the suction apparatus and
-19-
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pure air drawn through the absorbers for one to two minutes to remove CO..
The solution from each absorber was then poured separately into a colorimetrio
test tube. The absorbers were rinsed with discolored absorber solution and
the rinse poured into the test tube containing the test sample. The volume
of the liquid was brought to 1 ml* Mercury was determined with the aid of a
standard scale consisting of 8 test tubes containing respectively 0.05, 0-1|
0.2, 0.4, 0.6, 0.8 and 1.0 ml of a solution of HgClp, each ml of which con-
tained 1 Y of HS* volume ia all tubes was brought up to 1 ml using the previ-
ously mentioned discolored absorber solution. Then 0.2 ml of freshly prepared
Reyneke salt solution (0*0263 g per 100 ml of water) was then added to each
tube* The tubes were shaken and allowed to stand for 1 to 2 hours after which
the experimental tubes were compared colorimetrically with the tubes of the
standard scale.
The Determination of Ozone in the Presence of Hitrogen Dioxide and
Hydrogen Peroxide.
By
V. A. Shchirskaya.
Institute of .Industrial Hygiene and .Occupational Diseases, AHS , U.S.S.R.
Gigiena i Sanitariya, Ho. 8, 41-43, 1954.
The method of 02,one absorption by solutions of potassium iodide followed
by titration with araeneous acid and sodium thiosulfate has been widely used
for the quantitative determination of ozone under industrial conditions. The
same is true of K. S. Zverev's method of colorimetric ozone determination in
air* Ho vapors of nitrogen dioxide and of hydrogen peroxide which are often
present with osone interfere with the determination of ozone.
In search of a new method for the determination of ozone the following
were investigated! chromic anhydride as an absorbent for the fumes of hydrogen
- Academy of Medical Sciences.
-------
peroxide and eillcagel saturated with a 0.02 U solution of potassium dichromate
in concentrated sulfuric acid as an absorbent for nitrogen dioxide* The de-
sired concentration of hydrogen peroxide vapor was obtained as follows: about
11 ml of 1655 hydrogen peroxide was placed into a 200 ml flask; then under simi-
lar conditions of temperature, rate of air aspiration, type of glass absorbers,
etc., air samples were collected as follows: the outlet tube of the flask was
connected to a gas absorber containing 10 ml of water acidified with sulfuric
acid, and the air was aspirated through the system* The concentration of hy-
drogen peroxide vapor was determined colorimetrically* Next, air samples were
collected by alternate aspiration directly through acidified water and through
a U-shaped tube of 10 mm in diameter filled with chromic anhydride. These ex-
periments were performed with 0.005 to 1.1 mg of hydrogen peroxide vapor per
10 ml of the sample. In all the 10 tests the hydrogen peroxide was retained
in toto "by the chromic anhydride.
The effect of chromic anhydride on ozone was checked next as follows?
pure ozone was admitted through a gas outlet into a chamber where it was mixed
to even distribution. Air samples from the chamber were aspirated through 10
ml of 5J6 potassium iodide solution and the ozone concentration determined by
titrating the formed iodine with a 0.002 N sodium thiosulfate solution. The
same samples were then aspirated through the absorber after having been passed
through a U-shaped tube filled with chromic anhydride. Results of the deter-
minations are shown in Table 1.
Table 1.
Ozone concentration before and after
passing through ohromio anhydride.
Ozone ooncn.
in nig/li
Before
0,035
0,02
0.03
0.02
0,012
0,015
0,013
0,02
After
0.032
0,02
0,023
0,02
0,012
0,015
0,013
0,018
% of ozone
found
91
100
93 .
100
100
100
100
90
The data in the Table indicate
that the concentration of ozone after
the sample has been aspirated through
the chromic anhydride remained un-
changed or changed only slightly. The
maximum error did not exceed 10£.
Prior to investigating silicagel
as an absorbing agent for nitrogen di-
oxide it was necessary to ascertain
whether or not the ozone concentration
changed during the passage of the
o&one-contattting air through the ab-
sorber agent as such, and through the
-21-
-------
absorbent in the presence of nitrogen dioxide. For the first series of ex-
periments the absorbent was prepared as suggested by V* A. Klimova and U. 0.
Korshun ia their article "A New 3>ry Absorbent for the Collection of Hitric
Oxide in Determining Carbon and Hydrogen in Nitrogenous Organic Compounds.11
Granules of silicagel from 0.5 - 1 mm in size were placed into a flask with a
ground-to-fit glass stopper and after vigorous shaking 0*2 M potassium bio-
chromate in concentrated sulfuric acid was added drop by drop until the silica-
gel began to adhere to the sides of the flask. The silicagel thus treated was
then placed into a U-shaped tube 10 mm in diameter and ozone-containing air
aspirated through, it. The ozone concentration was determined before passing
the ozone-containing air through the absorbent by titration with a 0.002 H so-
lution sodium thioeulfate as previously mentioned. The data showed that the
absorbent had no effect on the ozone concentration.
Experiments were made with the absorbent prepared as previously described
and with the supplementary air-containing nitrogen dioxide concentrations
ranging from 0.001 - 0.02 mg/li. The nitrogen dioxide-containing air was
passed through the tube filled with silicagel saturated with 0.02 K K^Cr^O.
solution in concentrated HpSO.. Results of the experiments indicated that ni-
trogen dioxide in 0.001 - 0.02 mg/li concentrations was retained by the absor-
bent. The nitrogen dioxide was determined colorimetrically with the Gries re-
agent.
Table 2.
Ozone concentration before and after
passing through eilicagel treated
\rith .nitrogen dioxide-...
Results of the experiments are
^
presented in Table 2.
The data in Table 2 show that the
concentration of ozone in the air af-
Oaone conon.
in mg/li
After
Before
0,1 0.1
0,1 0,1
0,1 0.1
0.09 0,089
0,049 0.048
0,03 0,03
% of ozone
found
100
100""... -
100
99
98
100
ter passing through the absorbent be-
fore the absorption of nitrogen diox-
ide remained unchanged, or was only
slightly reduced*
Conclusions.
1. In the determination of .ozona
in the presence of H-O- chromic anhy-
dride can be used as an absorbent for
for the hydrogen peroxide vapor in
ZUur. Analitichaskoi Khimii, 4, No. 4, 1951-
-22-
-------
0,005 - 1.1 mg/li concentrations.
2. Finely granulated sillcagel saturated with a 0.02 U solution of po-
tassium dichromate in concentrated sulfuric acid retained nitrogen dioxide
present in the air in 0.001 - 0.02 mg/li concentrations. It can be used in
the determination of ozone in the air in the presence of nitrogen dioxide.
Determination of Chlorinated Hydrocarbons in the Air by the
Method of Micro-Combustion.
D. F. Senderkhina,
From the Erisman Scientific-Research Sanitary Institute.
Gigiena i Sanitariya, Ho. 8, 43-45» 1954.
Chlorinated hydrocarbons in the air have been determined by the combustion
tube method using alcoholic solutions of the tested substances. The method
consists of two operations, collecting the air sample at the testing point and
the analysis; both operations are time-consuming. The purpose of the present
investigation was to develop a new, rapid and sensitive method of analysis of
large numbers of air samples* In the experiments herein. reported this author
employed a micro-combustion method using a special combustion chamber developed
in the "Neftegazos'emka11 Institute originally designed for the differential de-
termination of small quantities of hydrocarbons* No reference has been found
in the literature to the possibility of using this apparatus in the determina-
tion of chlorinated hydrocarbons.
The method described herein is based on the quantitative oxidation of
chlorinated hydrocarbon vapor in a combustion chamber equipped with a platinum
coil heated to redness a The combustion products are then passed through an
absorber solution and the ionic chlorine determined nephelometrically. With
an appropriately prepared standard scale accurate determinations can be made
in solutions containing 0.001 mg of chlorine in 1 ml. Control tests were made
-23-
-------
with ethylane chloride, chloroform, carbon tetrachloride and triehlorethylene.
Low concentrations were prepared by dissolving known small quantities of the •
substances in ethyl alcohol or acetone. The assembled apparatus used consisted
of a purifying system, a concentration adjusting flask, a combustion chamber
and an absorber. The experimental tests were conducted as follows: a known
quantity of ethylene chloride was poured into the concentration controlling
flack, one end of which was connected to the purifying system and the other
end to the combustion chamber. The platinum wire coil of the combustion cham-
ber was connected to the electric light circuit. When the switch was thrown
in, the platinum coil was heated to redness. A Zaitsev absorber containing 5
ml of the absorber solution was connected with tho combustion chamber by means
of a side joint. The air containing the ethylene chloride vapor was aspirated
through the combustion chamber. In carrying out this procedure the absorber
solution was checked for the possible presence of chlorine ions using a solu-
tion of HgNO-i; such tests were either "negative" or "trace", while the wash so-
lution from the outlet of the combustion chamber gave a positive reaction* This
permitted the use of the combustion chamber end part as. an absorber* A
glass coil, moistened with the absorber solution, was inserted into the terminal
part of the combustion chamber to increase the efficiency of the absorber. Re-
sults of control tests established the utility of the proposed micro-combustion
method for the determination of chlorinated hydrocarbons in the air. The data
are listed in Table 1*
Table 1*
Determination of the ndcroabsorber
effectiveness
A
0,02
0.01
0.008
Of004
0,003
B
0.018
0.01
O.C076
0,0*38
0.0026
C
90
100
95
95
67
D
Nono
None
Trace
None
Hone
.
A - Hg of
of dichlorethane
tionj C - combustion in #j D - Mg of
diolorethane in 2aitsev absorber
In the course of performing ad-
ditional tests it was found convenient
to connect the absorber to the com-
bustion chamber by a ground-to-fit
connection. The absorber consists of
three partat l) small tubes ground-
to-fit at their upper ends and slight-
ly tapering at the lower ends] 2) a
glass rod coil of 13 to 20 coils fit-
ted firmly into the combustion cham-
ber} 3) a micro test tube having an
rtsorter'wLh Ml*. ^P*61 »«*• Hhioh the' tufca *ith th9
coil is firmly inserted* Before
-24-
-------
starting the analysis the coil ie thoroughly moistened with the absorber so-
lution and 1 to 2 drops of the solution are introduced into the test tube.
After each completed combustion the micro-absorber is removed and thoroughly
washed with the absorber solution and made ready for further use. The follow-
ing absorber solutions were tested for the absorption of the products of com-
bustion* an 0.01 H solution of sodium arsenite, a solution of alkalies, and
distilled water. All three absorbers yielded approximately the same results.
With the analytical apparatus described chlorine determinations were made on
a variety of chlorinated organic compounds. The results listed in Table 2
show that the process of combustion proceeded satisfactorily and did not depend
on the quantity of chlorine per molecule of the compound.
The next steps in this study were to
establish a procedure for the collection of
air samples into the gas pipettes, and the
method of transferring the samples from the
pipettes into the combustion chambers* The
following experiments were made: .known vol-
umes of a standard solution of ethylene
chloride in acetone were introduced into the
two gas pipettes of 500 - 600 ml capacity.
The pipettes were clamped at both ends and
kept until the ethylene chloride had become
vaporized} they were then connected to the
set-up. The test air was forced out from
Table 2.
Determination of chlorinated
hydrocarbons
Hydrocarbons '-
tested
2^4 «
C-HCl* i
<: 3
CC1.
4
CEC1,
3
•d
o
0>
to
s
^^
0,01
0,0032
0,0025
0,005
0,005
0.005
0,005
0,002&
Determined
Kg
0,01
0,0036
0,0024
0,0048
fi,006
0,0048
0,005
0,0024
< ft
* *tif* *
*! a i
O -H '
O
100
112
06
9t>
120
96
I0»
96
one of the pipettes into the combustion chamber by replacement with a saturated
solution of oodium sulfate. The substance to be analyzed was forced out from
the other pipette by replacement with chloride-free pure air. 0.01 H solution
of alkali was used as the absorber solution in both cases. Experience showed
that ethylene chloride "^por was completely replaced by the air or the sodium
sulfate and was forced totally into .the combustion chamber. After a while a
portable apparatus rcas constructed with which it was possible to perform two
operations within 20 to 30 minutes. The principal part of the apparatus, the
analytical part, consisted of two glass combustion chambers, two ground-to-fit ,
micro-absorbers and two air sampling pipettes. The second part of the appara-
tus, the air purifying system, consisted of two absorbers filled with a solu-
-25-
-------
tion of caustic alkali and activated carbon for the purification of the air
from chlorides and free chlorine. The apparatus is depicted in the accompany-
ing illustration. The analytical procedure in this caae was as follows *
/ Two Sas pipettes (a) which contained
the air to be analyzed, were attached to the
apparatus. The lower ends of the pipettes
were connected "by means of rubber tubes to
the level adjusted flasks (b) which contained
a saturated solution of sodium sulfate. The
upper ends of the pipettes were connected to
the combustion chambers (v). The micro-ab-
sorbers (g) were moistened with 0,01 K solu-
plug-in tion of alkali and were connected to the re-
spective combustion chambers (v) by ground-
to-fit adapters. One or two drops of the ab-
Apparatus for the determination 8Orber solution were then introduced into the
of chlorinated hydrocarbons
test tubes of the micro-absorbers. Then the
platinum spirals of the combustion chamber were connected to the light circuit;
after the platinum coils became red hot the lower clamps of the gas pipettes
were released and 5 - 10 ml of sodium sulfate run in from the level adjusting
flasks. The upper clamps of the gas pipettes were then released gradually,
allowing the air to pass through the combustion chamber at a rate of 25 to 30
ml/min. The total combustion time-was 20 to 30 ainutes. When the combustion
was completed, the pipettes were disconnected from the combustion chambers and
the air-purifying system was connected to the apparatus. Chloride and chlorine-
free air was aspirated through the apparatus for a period of five minutes.
Then, the niiero-absorbers were disconnected and washed individually with 0.5
ml of 0.01 N alkali solutionj the wash solution was run into the test tubes.
The total volume of the wash solution should not exceed 1 ml. Chlorine
was determined nephelometrically in front of a luminescent tube, trade marked
BS (white light). The wash solution was poured into flat-bottom calorimetric
test tubes marked at 1 ml. The standard scale was prepared from a solution
of potassium chloride or sodium chloride in volumes equivalent to 0.001 to 0.01
mg of chlorine at 0.002 mg steps. Then 0.2 ml of 0.1S6 of silver nitrpte solu-
tion was added to each test tube of the scale and to each of the tubes con-
taining the test samples which were then compared napheloiaetrically.
-------
The method described was applied under production plant and field condi-
tions with highly satisfactory results.
Conclusions*
1. A portable apparatus for the determination of chlorinated hydrocarbons
in the air by the micro-combustion method was constructed.
2* The micro-combustion method described proved to be accurate for the
determination of thousandths of a milligram of chlorine within 30 to 40 min-
utes,
3. A new micro-absorber is described which assures complete absorption
of products of hydrocarbon combustion*
4. Air samples are aspirated into gas pipettes filled with a saturated
solution of sodium sulfate or into vacuum gas pipettes.
Colorimatric Determination of Lead in the Atmospheric Air.
9y
V. A. Morozov.
Erisman Scientific Research Institute of Sanitation.
Gigiena i Sanitariya, No. 5, p. 46, 1954.
In the presence of lead salts quinalizarine produces a characteristic col-
or. The reaction is sensitive to 0.005 Y of lead in 2 ml. For the quantita-
tive determination of lead tvith the aid of this reaction a standard scale was
prep*>r«d in a set of test tubes containing 0.05, 0.1, 0,25i 0.5, 1, 2, 3, and
4 Y in a 2 ml. The resultant color in the test tubes ranged from yellow to
bluish pink.. The control tube had a yellow color. The water used in the prep-
aration of the standard color scale must be twice distilled, followed by 20
minutes boiling and have a pH 6.2 - 6.4. Copper, eino and iron must be removed
The original Russian text fails to designate the unit quantity of Fb, which
should be Y* B.S.L.
-27-
-------
from the test sample since they, too, produce color reactions with quinaliza-
rine* In this investigation the method of M. T, Golubeva was used in which
Cu, Zn and Fe are removed "by adding 2$% ammonia and ammonium chloride, 1 H:
sodium carbonate and calcium chloride. This method for the removal of Cu> Zn
' -and Fe was checked and found satisfactory.
Air dust samples were collected on filter paper. Disks were cut out from
ash-free filter paper and placed into an adapter through which air was aspi-
,-rated at the rate of 2 li/min. The disk was then removed, treated with 5 ml
of a boiling 3£ nitric acid solution for 10 - 15 minutes and evaporated to
drynees over a waterbath. The dry residue was rediesolved in water and trans-
ferred to a centrifuge tube to which were added 0,1 ml of 1 N sodium carbonate.
solution and 0.1 ml of 1 H calcium chloride solution. The mixture was brought
to a boil and centrifuged, the sediment washed with ammonia and distilled wa-
ter, again centrifuged, the sediment treated with 10£ solution of HaCfi, boiled
and again centrifuged.
The final lead solution was brought to a weak acid reaction by the addi-
tion of 3£ solution of nitric acid and evaporated to dryness in a porcelain
dish over a waterbath. The lead nitrate residue was dissolved in 2 ml of wa-
ter. A standard color scale of 8 test tubes was then prepared as previously
described* To each of the scale and test-containing tubes 5 drops of 0.00256
solution of quinalizarine in acetone were added and compared colorimetrically
after 2-3 minutes standing.
This method was used in the determination of lead in the atmospheric.air
around industrial plants the exhaust discharges of which contained lead. In
this study, 50 - 200 ml of air were aspirated through the filter paper. Lead
concentrations ranged between 0.05 and 2*75 Y/m *
-28-
-------
Determination of Active Chlorine in the Air.
*y
H. Q. Polezhaev.
(From the Institute of General and Community Hygiene, AM3 , U.S.S.R.)
Gigiena i Sanitariya, Ho. 11, p. 46, 1955.
Existing methods for the col or lice trie determination of small quantities
of active chlorine using dimethyl-paraphenylene-diamine-hydrochloride possess
high sensitivity; they can be used for the determination of chlorine in the
presence of hydrogen chloride in the absence of other oxidizers which produce
a si*ailar color.
In such methods the chlorine is absorbed directly into a dilute solution
of dimethyl-paraphenylene-diamine acidified with HC1; the reaction takes place
the moment aspiration of the air begins. The color produced in the solution
is not permanent; therefore, the colorimetric determination must be made with-
out delay. Comparison is made with an artificially prepared standard scale.
Higfc chlorine concentrations partly or totally bleach out the reaction color;
therefore, the following modifications were introduced. The dimethyl-para-
phenylene-diamine absorber solution was replaced "by a 1? potassium iodide so-
lution in a IS solution of sodium acetate* As the air is being aspirated
through the new absorber solution the free chlorine replaces an equivalent
amount of iodine. The standard solutions were prepared by dissolving known
quantities of iodine in the KI absorber solution so that one ml of standard so-
lution contained 0.01 mg of iodine/ Such a solution can be prepared from a
titrated 0*01 N solution by diluting it with the absorber solution. Iodine
dissolved in potassium iodide produced a red color with dimethyl-paraphenylene-
diamine which made possible the determination of the replaced iodine color!-
metrically; the amount of iodine thus determined was then converted to its
chlorine equivalent by multiplying the obtained value by 0.28* The absorption
of chlorine should be made with two micro-absorbers, each containing 2 ml of
absorber solution, and the air aspirated at.the rate of 15 li per hour.
Analysis of samples is carried out as follows i transfer the contents of
each micro-absorber individually into two micro test tubes, add one drop of
AMS - Academy of Medical Sciences.
-29-
-------
0.03£ dimethyl-paraphenylene-diamine-hydroohloride to all test tubes containing
the test samples and to the standard scale solutions simultaneously* Prepare
the standard scale as follow si set up 8 micro test tubes; beginning with the
2nd tube add standard iodine solution in following quantities* 0.05, 0.1, 0.2,
-0.4, 0.6, 0.3 and 1 ml; add absorber solution to all 8 test tubes up to the 2
ml mark* The first, or control tube will contain only 2 ml of the absorber so-
lution. How, add one drop of the dimethyl-parapheiiylene-diamine-hydrochloride
- solution to all test tubas, as mentioned above, and shake at once. The stan-
dard scale tubes contain 0.0, 0.0005, 0.001, 0.002, 0.004, 0.006, 0.008 and C.C1
mg of iodine, or the equivalents of 0.00014, 0.00028, 0.00056, 0.00112, 0.00168,
0.00224 and 0.00280 mg of chlorine. Leave stand for 15-20 minutes and com-
pare colorimetrically. To convert iodine to chlorine equivalent mutliply by
0.28. Knowing the amount of free chlorine present in a given volume of the air
sample it is easy to convert it to mg/m .
The modification here described has the following advantages: in mqir-jtig
the standard solution it is possible to utilize any easily titrated iodine so-
lution; the iodine in the potassium iodide absorber solution replaced by the
chlorine in equivalent amounts is highly stable and requires no immediate analy-
sis of the sample; a yellow tint appearing in the absorber solution serves as
an indication of an increased amount of chlorine and of the need to dilute the
absorber "by the addition of fresh absorber solution. In the course of the di-
rect absorption of high chlorine concentrations by the diluted reagent according
i
to the basic procedure originally prescribed for the modified method, the colori-
metrically useful color effect may become destroyed permanently. To avoid this.
from occurring the above stop may have to be carried out in some instances be-
fore the addition of the dimethyl-paraphenylene-diamine-hydrochloride.
-30-
-------
Fractional Determination of Hydrochloric Acid Aerosol and of
Chlorides in Atmospheric Air.
M. V. Alekaeyeva and E. V. Elfimova.
From the F. F. Erisman Scientific Research Institute of Sanitation
and Hygiene of the Ministry of Health of the R.S.F.S.R.
Oigiena i Sanitariya, Vol. 23, No. 8, 71-72, 1958.
In determining hydrochloric acid aerosol or hydrogen chloride gas in at-
mospheric air the fact was overlooked that chlorides were simultaneously pres-
ent in the air. Chlorides, like hydrogen chloride gas, are determined nephelo-
metrically as silver chloride. The present authors undertook to develop a
method for the determination of hydrochloric acid aerosol in the presence of
chlorides. To accomplish this hydrochloric acid was determined "by micro-titra-
tion and chloride ions nephelometrically; chloride gas was then calculated from
the two values.
The determination of hydrochloric acid aerosol in the air is complicated
"by the presence in the air of other acid aerosols, sulfuric acid aerosol in
particular, as was shown "by M. V. Alekseeva and K. A. Bushtueva? accordingly
it was necessary first to remove the H.SO., Results of tests conducted in that
direction demonstrated that in the determination of small quantities of hydro-
gen chloride, the latter was lost by the process of sulfuric acid removal. To
avoid the loss of the HC1, the following procedure was adopted: hydrochloric
acid aerosol was absorbed "by water which was then divided into three portions.
In the first portion total acid was determined micro-titrimetrically in the
presence of methyl red; in the second portion sulfuric acid and sulfates were
determined nephelometrically with barium chloride; in the third portion chlorine
ions nere determined nephelometrically with silver nitrate. Calculations were
a k 7
made by formula X - * * '. The total volume of the samples was 7 ml; determi-
nation was done in 2 ml. In the determination of HC1 (acid) a = alkaline solu-
tion in ml used in the titration of the 2 ml of the test sample; k = 0.182,
since 1 ml of 0.005 # NaOH is equivalent to 0.182 mg of HC1 gas.
In the case of sulfUric acid a is equal to mg of H-SO. found in 2 ml of
the test solution; k » 0.73 which is the coefficient of H-SO, conversion to
HC1. Hydrochloric acid aerosol and chlorides were determined by calculation
-31-
-------
from the proceeding two values. Control determinations were made with solu-
tions of known concentrations followed ~py testa on air samples.
Table 1,
Determination of hydrochloric and sulfurio acids
and of chlorides
Kg used
Ha
0.08
0,08
0.08
0.08
0.08
0,08
0.08
H,SO.
0,06
0,06
0.06
0.06
0,06
0.06
0.06
Chlo-
rides
0.04
0,04
0,04
0.04
0.04
0.04
0.04
Mg determined
HO
0,080
0.083
0,085
0.077
0,078
0,088
0,088
H,SO.
O.OfiG
0.06
0.06
0.05
0.06
0,072
0.053
Chlo-
rides
0.042
0.040
0,044
0.037
0.047
0,043
0,034
Percent of error
HCI
_
+3.7
+6,2
—9.4
-2.5
+ 10
+ 11
H,SO,
+ 10 •
—
—
—2.7
—
+8
+9
Chlo-
rides
+5
—
410
—7.5
+ 17.5
+7,5
— 15
The determination of hydrochloric acid aerosol in the presence of sulfuric
acid and chlorides gave good results, as is shown in Table 1. Micro-tit rat ion
was done with the aid of a micro-burette graduated in 0.001 ml with 0.005 N
alkaline solution preparad before the titration in double distilled water, using
2 drops of methyl red as indicator. The study of hydrochloric acid aerosol ab-
sorption was made as follows: first a concentrated aerosol was accumulated in
a glass flask by passing through it a continuous stream of hydrochloric acid
vapors and humidified air. The aerosol was then aspirated through two absorbers
connected in succession. The first V-shaped absorber had a porous filter Ho* 1
and 7 ml of twice distilled water free from chlorine ions; the second (Zaiteev)
absorber contained 5 ml of water. Aspiration rate was one li/min. The aerosol
of hydrochloric acid was retained completely by the first absorber from an air
concentration of 5 mg/m . Increase in the aspiration rate to 3 li/min carried
over 5 - 10£ of the aerosol of the concentration into the second absorber.
The analytical procedure described required constant checking of the water
and of the absorbers; there must be no reaction between the glass and the water.
Such checking is done as follows: fill the absorber with twice distilled water
to capacity; two drops of methyl red added to 2 ml of the water should indicate
a neutral reaction. Leave the water in the absorber for 24 hours and check
similarly for neutral reaction. In the case of slightest suspicion replace ab-
sorber by one similarly checked.
The method was used in analyzing 37 samples of atmospheric air. Some of
-32-
-------
the results are shown in Table 2. Air samples were collected for 4-7 hours
under different meteorological conditions. The results proved that aerosol
of hydrochloric acid can be present in the air.
Table 2.
Determination of hydrochloric acid aerosol in atmospheric air
.
-•
A
27/1 V
3/V
47V
IO/V
M/V
15/V
22/V
23/V
Determined
B
600
250
400
420
300
300
420
•400
_
C
0.016
Her
0,032
0.028
0,030
0.041
0,001
0,001
D
0.029
0.007
0.052
0,011
0,008
-0,024
0,(>OG
0.001
S
_
--
—
0,017
0.022
0.017
—
P
OieAW
0,035
0.013
0.032
0.022
0.112
0,009
*
G
—
—
—
0,04
0,073
0.05G
—
~
Meteorologic
conditions
Clear
Clear
Clear
Drifting clpuds
oocas* preciptn.
Ditto
All day precptn*
Ditto
A - Date of air analysis* B - Volume in liters* C - Total acid as
HC1 in g? D - H^SO., sulfates, as HC1 in g; E - HC1 in mg; | - 10-
tal ionic cElofine in mg; G - HCl concentration in mg/m .
Determination of Dust in the Ataosphoric Air with an Electrophotocolorimeter.
^y
B. V. Kykhter and N. V. Shlygina.
Pezm Oblast Sanitary-Epidemiological Station.
Gigiena i Sanicariya, Vol. 23, No. $, 18-22, 1958.
The usual gravimetric method for the quantitative determination of atmos-
pheric dust collected by aspiration through ash-free filters or cotton wool has
serious shortcomings; outstanding among these is the necewsity to collect sam-
ples over 2 hours even at an aspiration rate of 30. li/min in order to obtain a
sufficient quantity of dust for the determination of ms\irtmm single concentra-
-33-
-------
tions. Frequent changes in wind direction during such a long interval do not
permit the collection of complete samples in the smoke flume, and as a result
a lover content of dust in the atmospheric air will be obtained. The second
shortcoming of the gravimetric method is the amount of work required! it takes
7-9 hours to obtain 3-4 samples at different distances from the pollution
source. It should be pointed out that reducing the filters to a constant
weight is also a time consuming procedure.
Such shortcomings of the gravimetric method induced the authors to search
for a simpler method for the determination of dust concentrations in atmospher-
ic air. The use of the photonephelometric method offered a satisfactory solu-
tion. Dust samples were obtained with the aid of Hykhter's model 7? general-
purpose liquid absorber. The alcohol-glycerine mixture, recommended by M. T.
Berkovich for use in determining air dust concentrations in mines was used as
the absorber solution. The procedure proposed by M. T. Berkovich in a modified
form was first tested in an experimental chamber, in this test the Fetri ab-
sorber was replaced by Bykhter's 7? absorber which permits air aspiration at a
rate up to 20 li/min, whereas the M. T. Berkovich absorber limits the air aspi-
ration to 2 li/min* For purposes of comparison samples were collected simulta-
neously at the same 17 li/min aspiration rate at the same point using a cotton
wool adapter and also a liquid general-purpose absorber. Aspiration lasted 3 -
4 minutes* The samples collected into cotton wool filters were analyzed by the
usual gravimetric method. Samples collected into the liquid absorber were ana-
lyzed nephelometrioally using an electrophotocolorimeter. The standard curve for
coal dust concentrations was plotted as described by M. T. Berkovich. Table 1
shows that the methods tested yield similar results, thereby indicating that
Table 1 tn9 general-purpose absorber method and the neph-
elometric method for the determination of air
pollution with coal dust could ta used for the
determination of other dusts. Degree of disper-
sion was determined with a Zeiss konometer. In
determining dust density of atmospheric air with
the aid of the electrophotocolorimeter specific
standard nomographs must be plotted for each type
of dust.
Up to the present studies were limited to
Checking gravimetric and
nopheloinatrio re cults in
experimental dust chamber
ra
9
E-»
Particle
sigea in i
2-5
in~£
>5
92
95-
94
96
3.3
5
6
4
Duet
in
41
54.5
54.5
94
67,2
65.6
47
99.4
-34-
-------
dust coming from smoke gases of boilers-operated plants, electric power and
heating plants using "kizelevskii'1 coal, and cement dust discharged with smoke
gases by a cement-metallurgical plant. To plot the first standard nomograph
showing the functional relation between dust concentration in boiler room smoke
and photocurrent, the dust was collected from the atmospheric air by aspiration
using a metal adapter and a cotton filter from the smokestack piiae streaming
over a Perm workers village*
Twenty-five mg of the dust was suspended in 50 ml of an alcohol-glycerine
mixture j the control tube contained only the alcohol-glycerine mixture and the
dust density was evaluated. The evaluated suspension was diluted with an equal
volume of alcohol-glycerine mixture and again evaluated nephelometrically; this
procedure was repeated until the photometer reading of the control and diluted
suspension were identical. On the basis of data a curve (nomogram) of photo-
current relation to dust concentration was plotted as shown in Fig. 1.
To verify whether dispersed atmospheric
dust had any effect on the readings of the
electrophotocolorlmeter, and on the degree of
completeness of atmospheric dust collection by
the general-purpose absorber, a control test
was conducted comparing the results with coal
dust collected by the liquid absorber method
in the experimental chamber. In all experi-
ments the aspiration rate was 20 li/min and
the duration of atmospheric air- aspiration was
10 minutes. In the case of coal dust collec- .
tion in the test chamber the duration of sam-
r m
•P
§-H
^Q
•** 5
o *d
c
•H iH
4» (0
^1
Pi
w
0J3
o&
0.2S
Q.IS
Off
Sfl
a
>
j
' i »
t
1
s
s
\
{
t
1
1
#
2S
'
7$
»
72
H
t
£
>
ji
s
rf
/
1
t
g
1
t
I I >
\JT
Jfl--
t
1 „
0 *
a
20 /*
J? JS 40
Bust concentration in mg
Pig. 1. Functional relation
between "photocurrent and' at^
mospheric dust concentration
ple collection varied between 2-1/2 and 4 minutes. Atmospheric as well as" coal
dust was collected using a 111 alcohol-glycerine mixture. Ten ml of this mix-
ture was placed into each absorber. The results of the experiments are pre-
sented in Table 2.
The retention of dust by liquid absorbers alone in the case of finely dis-
persed dust amounted to 90 - 96%, and in the case of dust from boiler smoke
flumes the retention was 90 - 10<#. The results of the investigations justify
the'conclusion that collection of dust with liquid absorbers from smoke gases
of boiler rooms was entirely adequate and differed only slightly from the coal
-35-
-------
Table 2.
Atmospheric dust (sooty ash) and coal dust retention capacity
of the general absorber fluid
Pest
Ho.
*
2
3
4
5
6
7
8
9
10
Particles in |i >
<2 | 2~*
> s
(in per cent)
Mg/io3^
air
dust
Dust retained
in mg
absorBSr
SSBSRlr
f^v
•P «
e o a
« 0-rt
Atmosphere (boiler smoke)
95
98
89.4
91.7
5
2
6.4
8.3
0
0
4.2
0
0.56
o;«
1.6
7.9
0.113
0.128
0.29
14.3
0
0
0.03
1.5
100
100
91
90
Experimental chamber (coal dust)
90.5
92.7
81
81.4
96.8
87,6
9.5
6.3
19
H.6
3.2
10, 1
0
1
0
7
0
2.3
9.5
15.3
15.7
17.9
19.3
23,9
0.725
0.963
0.89
0.82
1.05
1,15
0.032
0.106
0.054
0.0-5
0,109
0.045
96
90
94
92.6
91
96
dust collection results. Dust retention was attainable with one absorber to
the extent of 90.5 to 100£. The use of standard curves for atmospheric dust
obtained from the dust stream from boiler rooms and plotted on the same basis
as coal dust proved completely satisfactory, and alight fluctuations in the
size of dust particles did not affect the photocolorimeter readings.
For the determination of atmospheric air pollution with cement dust a
special standard curve was prepared using
weighed portions of this dust as shown in
Figo 2. As an illustration of the electro—
photocolcrimetric determination of atmos-
pheric air dust concentration a concrete
example is presented. Table 3 presents data
on dust density of atmospheric air in the
center of a Perm workers' settlement obtained
during the first quarter of 1956. The sam-
ples were taken at .a fixed point with the
s
4*
C -rt
o o
•H C
•** w
O'A
•** aJ
M O
P3 -H
-P
ft
i:
IB 20 zz
OSS
O9tt
HZ9
n?7
1"
a
'
,
s
'
\
At
>
fg
7?
if
ff
,
/
xr
t
.
f
*
"'
•*
4
^
•*
^
,
ff
,
,
^
i
^
/
,,
^
a
"*
(
,^
'
1
t ^
'
-
c
25
Dust concentration'in mg , , J,«,,A . ,,-
aid of Bykhter's model 7? general-purpose
Fig. 2. Functional- relation ,4 ,, . , « . .. . . , ,
between photocurrent and at- li
-------
outside air temperature, barometric pressure and weather characteristics, such
as clear, cloudy, overcast, snow, etc, were recorded. In this study the monoc
ular electrophotocolorimeter was used, built by the Leningrad Institute of La-
bor Protection. Accuracy of the method in 10 ml of alcohol-glycerine mixture
was 0,08 mg.
The allowable limit of maximum single dust concentration in atmospheric
air is 0.5 mg/m , for the determination of which it is sufficient to aspirate
(0,08 i 1000): 0.5 « 160 li of atmospheric air. It is recommended that col-
lecting of samples continue 10 - 15 minutes at a rate of 20 li/min, which per-
mits the determination of dust concentrations in atmospheric air up to 0.4 -
0.26 mg/m . Results of the air dust analyses made at the Perm workers village
are listed in Table 3.
Table 3.
Dust pollution of the atmospheric air of the center of
Workers' Village Perm during the first quarter- of 1956
Primary
pollution
source
o
1"
Air
i
n ing
•
§
•S*
£g
•H
t*
H 0
p o
> (0
.
•38 •
at-'
O
-------
termination ~>f atmospheric air dust concentration with other types of indus-
trial dust. To eliminate the effect of dust created by traffic during the
warm season of the year the investigations should be conducted preferably af-
ter a rain or at some distance from the highways„
An important factor in determining the dust concentration of atmospheric
air with an electrophotocolorimeter is the stability of dust suspensions in the
absorbing solution. Special experiments were carried out for the clarification
of this point* The results showed that dust suspensions remained stable and
that it was possible to make determinations with the photocolorimeter several
days after samples were collected which constituted a point of great practical
significance.
The methods developed for the determination of dust concentration in at-
mospheric air permitted rapid collection and analysis of air samples and are
applicable to the evaluation of the effectiveness of dust-removing equipment.
The advantages of the electrophotocolorimetric method over the gravimetric
are self-evident; samples can be collected and analyses made under all types
of operating and processing conditions, and maximal single dust concentrations
can be determined in a short time with a high degree of accuracy.
Bibliography.
BepKOBH'iM.T.. 3anoji. *a6opaT., 1952, T. 18. J* 10. crp. 1204—1206. — Pwx-
f ep 3. B., far. H can. 1951. Ni 5. crp. 15—18. -,- OH we, 8 KB.: MaiepHa^u Bcecows-
noro coBemaHHB no CesonacHocni paOor B SHeproycraHOBKax, MOJIOTOB, 1955,
crp.97—118. — P a 3 a H o B B. A.. Ajiexceeaa M. B, C e R a e p H x B H a H. H-, B
KH.: IlpejxejibHO AOnycTHuue KoaneuTpauaa aTMouJttpubUt MrpjUHeaafl, M, 1952. B. 1,
crp. 107—146.
-38-
-------
A Chromathermographic Method for the Separation of Hydrogen, Carbon Monoxide,
Methane and a Mixture of Hare Gases.
By
N. M. Turkel'taub, 0. V. Zolotarova, A. G. Latukhova, A. I. Karymova and
. Ye. R. Hal'nina.
Prom the All-Union Scientific Research Geologic Prospecting Oil Institute.
Zhur. Analit. Khiraii, 11, Ho. 2, 159-166, 1556.
The differential determination of hydrogen, carbon monoxide, methane and
rare gases is cf importance to the oil, chemical and electro—vacuum industries.
In chromathermographic analysis (l), hydrogen and carbon monoxide migrate
as a group with methane; therefore, the fracticn which contains hydrogen and
carbon monoxide has to be analyzed further by the method developed at the
Dzerzhinskii All-Union Heat Engineering Institute. Existing methods for the
determination of rare gases are limited to the separation of helium and a part
of neon by adsorption-removal of all other components with the aid of charcoal
at the temperature of liquid nitrogen.
The problem of the chromatographic separation of the above mentioned gases
was dealt with recently by E, Tanak (2) who proved that rare gases, carbon mon-
oxide and hydrogen can be partitioned chromatographically. However, the proce-
dure used by Tanak, in which C0? was used as the developer and the separated
gases were determined with the aid of a burette, made no provision for the sepa-
ration of carbon monoxide and argon from oxygen and nitrogen.
The present study differs from Yanak's in that use is made of additional
developers and fixation agents; a chromathermographic procedure represents an
improvement in the separation process and eliminates the need of low tempera-
tures. This is accomplished by using large quantities of the adsorbent to com-
pletely remove the substances of low sorption properties. Tests were made with
finely porous and coarsely porous charcoal of brands AG and KAD. The charcoal
was dried to a constant weight at a temperature of 200 and activated supple-
mentally "by subjecting it to the effects of vacuumation of approximately 10 nan
of mercury and heating up to 400 for a period of eight hours. The study pro-
cedure was as follows t a given quantity of the activated charcoal was placed
into vertical glass columns and known quantities of hydrogen, carbon monoxide,
methane and, either one of the rare gases or a mixture of them were, deposited
-39-
-------
Ll
on tha adsorbent at room temperature. The chroma t he rmogram was developed ei-
•> *
ther lay means of air or carbon dioxide, while an electric heater provided with
a heat control moved along the column. When developing was accomplished by
means of carbon dioxide, chroma thermograph model 4 (3) was used* In this case
L!
a micro-burette filled with 40£ KOS solution was used in the fixation process.
The carbon dioxide was absorbed toy the KOH and the dee orbed gases were col-
lected in a calibrated micro— burette. When a chroma the rmogram was developed
by means of air, an apparatus based on measuring gas heat conductivity was used
as the fixing device} the apparatus had a chemical heat gas analyzer similar to
the one used in the determination of combustion heat. The apparatus is sche-
matically presented in Fig. 1.
A. The separation of
hydrogen t carbon monoxide
and methane. Hydrogen , car-
bon monoxide and methane in
volumes of 0.5 to 5.0 oo
were deposited on a piece of
coarsely porous charcoal AG,
weighing 57 S and the chrc—
matogram developed by passing
an air current at the rate of
100 cc/min. A continually-
acting chemical heat gas ana-
lyzer was used as the f ixa-
tition was determined as
KOH soln. follows* amount of the sub-
stance equal to that deposited on the charcoal was aspirated through an empty
tube after which air was blown through the tube. A fixation device at the tube
recorded the amount of gas in the form of a curve. Coincidence of the areas em-
braced by the test and control curves indicated that desorption was complete.
Adsorption of hydrogen by charcoal at room temperature is practically nil. A
hydrogen concentration of l£ was liberated after it had been deposited on 57 g
of coarsely porous charcoal AG with the developer passing through it at the
rate of 100 cc per minute. The maximum concentration of hydrogen was recorded
To analyser
Pig. 1. Chroma thermograph Ho. 4s 1 - flow»»i«rj
£ - C*C12 drierj 3 - adsorbent column} ' 4 - elec-
trio heater; 5 ~ microburett* with
-------
on the curve after 150 to 300 co of air passed through the charcoal. Under the
same conditions carton monoxide was liberated after 350 cc of air developer had
passed throutfij the maximum hydrogen concentration on the curve was recorded
after 350 cc of air had passed through! complete desorption required 550 - 600
cc of eluting air. Methane began to be liberated after 600 cc of air? the
maximum of methane concentration was observed on the curve after 950 co of air
passed, and complete desorption after 1200 cc of air had passed through, The
above results indicated that 57 g of coarsely porous charcoal AG was . adequate
to assure complete desorption of hydrogen, carbon monoxide and methane.
The next test was made with 48 g of finely porous charcoal AG. The ad-
sorption of hydrogen by the finely porous charcoal is also practically nilj
however, carbon monoxide and methane were better adsorbed by the fine than by
the coarsely porous charcoal. Carbon monoxide begins to be liberated after
500 cc of air had passed, but methane begins to be liberated only after 1200
cc of air had passed. A study was also made of the effect quantitative ratios
of H , CO and CH. on their complete partitioning. The results presented In
Table 1 show that complete partitioning of the components occurred when com-
ponent ratios were several times greater than one.
_ . , , It was of interest to
Table 1.
. - 100 oo/ndn. examine the nature °f 8OTP"
tion and the cause of hy-
drogen, carbon monoxide and
methane partitioning at
room temperature, and also
the cause of the greater
sorption of carbon monoxide
than of nitrogen. It was
assumed that in the pres-
ence of basic oxides on the
surface of the charcoal the
process of carbon monoxide
sorption was cf the type of
activated adsorptions. To
check the correctness of
Coal AG, 48
9est \ Composition
of gas mixture
i
2
4
5
6
7
»W* • • «
>oH monox?
Hydrogen
uw-nhpn i&onax'.
monox.
Lrbofi monox.
Kethane
o
215
0
250
0
300
315
1100
0
300
,1100
'200
600
0
200
500
215
600.
ZW
600
250
800
800
2UOO
200
8UO
2000
fiOO
10UO
200
11UU
1,00
1,00
3.00
0,50
0.50
4,00
5,00
0.50
2,10
2.10
2,0
5,00
0,50
2,10
2,10
2,00
0.90
0,90
3,00
0.50
0,45
4,00
5,10
0,45
2.20
2,20
1.90
5.00
0,50
2.20
2,20
1.90
Re-
marks
Dry
Wet
1 - Separation beginning in cc deraloperf 2 - Sep- thia *s8UB**ion the
aratlon end in oe developer j. 3 - Taken in eo| 4 — coal was left in an atmos
Doterioined in oo«
-41-
-------
phere of humid air for 19 hours to increase the number of oxide groups. How-
ever, this method was not as effective as the clocking out of adsorbing areas
by means of water, as can be seen fro* data plotted in Pig. 2.
The solid line in Pig. 2
represents plots of separation
on dry charcoal, and the dashed
line indicates plots of separa-
tion on charcoal processed as
above described.
Partitioning of hydrogen,
carbon monoxide and of methane
was tried also with 94 g of dry
charcoal KAD; the partitioning
too
1100
co of air
Pig. 2. Curve of yield.
Hydrogen—carbon monoxide-air mixture
was clearcut and the desorption
complete. To expedite the analy-
sis, the developing was done by
means of air washing and electric
heaters moving at the rate of 3 cc/min.
The determination of the amount of liberated gas at low concentration by
means of curve area coincidence is a tedious procedure. Furthermore, a con-
tinually operating gas analyzer is not always available. Therefore, use was
made of the method of measuring portions directly in the KOH-filled burettes.
Table 2 and Pig. 3 present some results of the separation of gases referred to,
using 94 g of charcoal KAD at air developer rate of 40 cc/min. Under the con-
ditions described carbon monoxide did not separate from either nitrogen or oxy-
gen. The total time required for the analysis was 30 minutes. The accuracy
of the results depended on the accuracy of measurements, completeness of ad-
sorption and the purity of the carbon dioxide. The relative determination er-
ror was 0.3$.
oo of gas
- -.. - . j
2
0 80 eo 240 320 400 4SO 950 640720 SOO 630 96O at* 8^
Pig. 3. Yield curve of hydrogen-air—methane mixture
-42-
-------
Table 2.
Charcoal KAD, 94 gf r » 40 oc/ndn
°2
Test
Ho
i
2
3
4
S
6
7
Gaa mixture
composition
Hydrogen
Air
Hydrogen
1
4-
2
340
000
140 .140
Air » 360
Methane : eoo
480
380
1120
Hydrogen * 240 xm
Methane
Hydrogen
He thane
Hydrogen
600 1120
80
280
660
60
260
420
940
260
Air t 260 400
Methane , eoo io60
Hydrogen ! eo 260
Air 280
Methane «on
420
1020
3
10,2
6,3
21,0
21.1
9,7
21,3
21,3
4
10,3
6,2
21,1
21,3
9,7
21,3
21,3
1 — Separation "beginning in co developer?
2 - Separation end in cc developerf 3 —
Taken in ccj 4 - Determined in oc
B.. Separation of rare
The partitioning of a mixture of
rare gases into components was
based on the chromathermographic
partitioning previously developec
and on the analysis of a mixture
of hydrocarbon gases. 94 g of
charcoal KAD was used as an ad-
sorbent, and either carbon dioxic
or air was used as the eluter or
developer. The yield curves of
helium, neon, argon, krypton, xe-
non and their mixtures are plottt
in Pig. 4o Experimental condi-
tions were as follows: speed of
developing of COp (v) • 50 cc/mi
rate of the moving electric heatt
(w) m 3.0 cc/min, and maximum ten
perature of the heater (t )
v max7
290 ; under such conditions helium began to be
liberated after 125 cc of carbon dioxide had passed through; 250 cc of carbon
dioxide completely eluted the helium from the adsorbent. Neon was liberated
simultaneously with helium. The yield curve for helium coincided with that of
neon in a superimposed manner. Argon began to be liberated after 250 cc of
carbon dioxide had passed .through; and 400 cc of .carbon dioxide eluted it com-
pletely. The beginning and end of the liberation of krypton occurred respec-
tsoo
2200CM'CO^
Pig. 4. Yield curve of helium-argon-krypton mixture
-43-
-------
tively after 425 cc and 625 co of carbon dioxide had pae&ed through. The be-
ginning and the end of xenon liberation occurred respectively after 1800 cc
and 2200 cc of C02 had passed through.
It should be noted that helium and argon were virtually moving ahead of
'-the heater, krypton and xenon moved with the heater and became liberated at
their respective characteristic temperatures, A study was then made of the
relation between the completeness of partitioning of the rare gases, the amount
-*of the substance deposited and the composition of the gas mixture. The results
showed that even with hundredfold changes of individual components the parti-
tioning of a mixture of helium, neon, argon, krypton and xenon was practically
complete. When 100 cc of the mixture was deposited on the charcoal, the re-
spective contents of rare gases were determined with a precision up to 0.3$.
The shortcomings of the chromathermographic procedure using chromathermo-
graph No. 4 rested in the fact that when samples contained nitrogen, argon be-
came adsorbed together with the nitrogen. For this reason the separation of
rare gases had to be made with the aid of chromathermograph Ho* 5 which elimi-
nated the nitrogen interference in the process of argon adsorption due to the
difference in their respective heat conductivities.
Fig. 5 depicts the yield curve of a mixture of helium, argon, krypton and
xenon partitioned at development rate of (v) « 60 cc/min; rate of heater (w) a
3.8 cc/min, and marl mum temperature of the heater (*___) » 205°- Partitioning
of the components and reproducibility of analytical results were good. Results
of the chromathermographic partitioning of rare gases are shown in Tables 3,
. 4 and 5.
Gas in %
a
10
o
8
BD 360 GW 84Q £00 ttiBD /S2O 2SOZZ3O QQ of air
• 5* Tiold curve of holiun-argon-krypton-xenon sdxtore
-44-
-------
Table 3.
Chromatheraograph Ho. 4t Charcoal KAD, 94 *
v«>. - 4° coMn.
Toa-t
Fo
i
2
Composition
of gaa nrfjct.
PelioB
felina
Air
3
4
o
6
7
Heliua
Air
Heliun
• M
AijP ^
Krypton .
Argon
Argon
KrypTon-
Argon
; Krypton
1
80
8U
300
60
280
80
220
88U
300
300
880
300
880
2
360
280
440
260
500
200
(120
1260
620
500
1260
GOO
1300
3
7,6
6.8
12.1
22.2
7.2
6,5
14.9
4
7,7.
6.8
**•**
12.0
22,3
7.2
6,4
14,8
1 - Separation beginning in oo developer;
2 - Separation end in oo developer; 3 -
Taken in ooj 4 - Determined in oo.
Table 4.
C&romathersiograph Ho. 4} charcoal KAD, 94
eo.
50 cc/ndn. j w =3.0 on/min.
Test
Ho
4
1
*>
£
•*
V
4
5
/oBzpositn*
of - gae
mixture
Air
Krypton
Air
•• **
Krypton
Air
^ • fc
Krypton
Air
" * m
Krypton
Xenon
Krypton
Xenon
-1
i
: 225
425
^1ff*J
225
425
200
400
150
400
1500
175
375
A ^fTil
Io50 •
2
'
400
UjO
375
650
400
650
400
"675
2700
350
:,?3
*\**j Wfc
21 rflU
3
'
•i,"
4,0
10,0
100,0
10,3
4
M
4,0
n,9
100,2
10,6
Remark*
W«ir*»*
Ditto
» t
'max = 270°
Ditto
1 - Separation beginning in eo developer} 2 * Sep-
aration . end in eo developer) 3 - ffakan in oo|
4^ Determined in oo.
It was shown previously
(8) that under conditions of
constant temperature of the
electric heater, constant
rate of the heater and devel-
oper movements a strict rela-
tion existed between the mag-
nitude of the high point on
the yield curve and the degree
of the initial concentration.
Calibration curves which show
the relation between the con-
centrations at the high points
of the yield curve and the
initial concentrations were
plotted on the basis of dif-
ferent concentrations of in-
dividual components under
known conditions and the
concentration values at
the mgff ftn»n points of the
yield curves. Results of
numerous experiments in-
dicated that concentrations
of rare gases in a mixture
can be determined by the
chrofflathermographic method
with an accuracy of O.l£,
and concentration of helium
with an accuracy of 0.01%.
The time consumed by analy-
sis was 45 minutes.
It should be noted
that the accuracy in deter-
mining rare heavy gasaa may
-45-
-------
Chromatograph Ho* 5$ charcoal KAD, 94
v . -60 cc/min.; »s>3»8 oo/ndn.>'
Test
No
i
2
! Composition
of gas mixture
Helium
:Krypton
Xenon
^Helium
Argon
jiKrypton
Xenon
H
_..
90
300
1170
1890
90
1170
1S90
2
270
600
1710
2220
270
540
1710
- Separation beginning in cc of developer;
2 - Separation end in oo developer.
Table 5 • be increased by depositing a
greater amount of gas on the
charcoal* For instance, the
initial concentration of xe-
non * 0.001%. After depos-
iting 20 Ii of the gas, the
concentration at the point of
maximum on the yield curve
rose to 1.3£. The ratio of
the concentration at the point
of mgyimun* on the yield curve
to the initial concentration
is here designated as the
"enrichment coefficient" which, in the case under consideration was 1.356, It
follows that with the aid of the chromathermographic method rare gases can be
determined even in a concentration of 0.00116.
Conclusions.
1. A description is presented of a chroma therm ographic method for the
analysis of mixtures of hydrogen, carbon monoxide, and methane at room tempera-
ture. The analysis requires only 0,1 cc of the gases; time required" is 30
minutes, and the precision in 0.3^. The method permits differential determina-
tion of the components above referred to in an air mixture,
2. A chromathermographic method for the separation arid analysis of rare
gases is described. The method makes possible the determination of the total
content of helium, neon, argon, krypton and xenon with a high accuracy. The
accuracy of the determination is 0*3£ with the aid. of chromathermograph No. 4>
and 0.01$ with the aid of chromathermograph No. 5 5 the accuracy of the deter-
mination of heavy inert gases was as high as 0.001$.
Bibliography.
II. M., ;\.\\l M. .\- 1 (ll)'.i).
VK y \ b B u n K u ii A. A- H "!' y p i; t- .'i l> T a V
J a'it a !; J., Chirm. UU|UJIIK MextH-.iGBaiiKrt.v .xiiMttiuCKiix puuor 19, 08-4 (l!£'i).
VK y x o B n it K n ii A. A., "= o n o T :i pen a ("'. B., C o K o n o B H. A. n T y p-
K*v.ii.TMy 6 II. M., AAII 77. 3 liUat).
5K v x o B n u K n ii A. A.. T y p KC a b T« y u H. M. » I" c o p r a c n i: K ;i 11 T. U.,
IKS. .Vs .•>•-
-46-
-------
Quantitative Extermination of Dichlorebenaene Isomers.
* " '
A* A* Spryskov and Tu. G. Erykalov.
Ivanovokii Chemical-Technological Institute.
Zhur. Analit. Khlsii, 11, Ho. 4, 492-494, 195$.
During the chlorination of "benzene or of chlorobenaene ortho— and para-
isoners are formed with a small quantity of the meta-isomar. The first means
for the quantitative determination of the dichlorobenzene isomers in a mixture
was a thermal method proposed by Van der Linden (l). The method is based on
the fact that ortho- and meta-isomers lower the solidification point of para-
i seniors to an equal degree as long as the content of para-iaomers is above 45&.
Consequently, the content of the para-iaomers can "be determined by adding pure
n-dichlorobenzene to the mixture, if so required* The ratio of ortho- to meta-
isomers can be established by determining the second solidification point after
the para-isomer has fallen out.
Zil'berman and Oorisch (2) made a study of polychlorides at a chlorobenzene
plant, but their determinations were limited to the ortho- and para-isomers and
disregarded the determination of the meta-isomera. Determinations were made by
fractional distillation, solidification temperature and by fractional specific
gravity. Japanese investigators (3) determined o- and n-dichlorobenzene in a
binary mixture by finding the dielectric constant by the resonance method with
the aid of a high frequency oscillator. In this case the meta-isomer content
also remained undetermined. Van der Linden's method is the only one which makes
possible the determination of all three isomers. However, as Van der Linden
pointed out, his method can not be always relied upon, since the second points
of solidification are very difficult to establish, probably because they lie in
th© region of IOB temperatures. In many cases the fall-out of the solid phase
is so voluminous that it becomes impossible to stir the mixture.
The present authors approached the problem of determining all three di-
chlorobenzene components in a mixture as follows t a thermal method was used
for the determination cf the para-isomera and a bromide-bromate method for the
determination of the meta-ieoaors after an amino-group was introduced into the
ring. The bromide-bromate method has been used previously for the determina-
tion of isomers of toluidino (4), xylidine (5), and other amines, aa well as
-47-
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phenols and nitro-compounda, after the last tbrea were reduced with titanium
trichloride.
Srperiaental part. To determine n-dichlorobeazene in a mixture, a section
of the thermal curve was checked for temperatures of solidification in a mix-
ture containing para-, ortho— and meta-isomers. The results shown in Table 1,
plotted graphically, produced a smooth curve which coincided with the curves
of binary compound mixtures, either of para- and ortho-leasers or of para- and
meta-isomers. After the content of the para-isoaer has been determined by the
solidification point of the mixture tested, the mixture was subjected to ni-
trating and reduction for the determination of the mata-isamers by the bromine-
bromate method. . Approximately 1.5 g of the substance to be analyzed was mixed
with an equal portion of water by weight; it was then cooled for 30 minutes and
15 g of nitric acid of 1.3 sp- gr» added to the mixture a few drops at a time.
Table 1.
Solidification point of mixtures of c-f m- and n-dichlorobenzene
& chlorobenzene
in mixture
n- 1 o-
83,0
80,8
80.3
71,1
7o;i
0
9,6
13;3
17,7
29,9
M-
17,0
9,6
6,4
11,2
0
^i^J^FS,
soli oil/
V
43,8
42,5
42, ()
36,6
36,4
% chlorobenzene
^ in mixture
n-
66,8
64,6
4lr8
41,0
33,7
o-
22,7
33,4
31,2
29,2
44,6
M-
10,5
0
27,0
29,8
21.7
Miff.
temperature
33,8
32,1
13,5
12,8
4,8
After 30 minutes the mixture was poured into a separating funnel contain-
ing 50 ml of water, and the product was washed until the reaction of the wash
water became neutral; if the product solidified the water was warmed up. The
nitre-compound was mixed with 6 g of zinc duet in a wide test tube; the test
tube was connected to a grcand-to-fit tub® which served as a return air condens-
er. During the cooling period 30 to 40 ml of hydroohlorld® acid of 1.13 ftp* £?»
uas addod gradually with care until the sine dust completely dissolved during
the following boiling of the solution over a wire gauae. The reduction process
took approximately one hour. The hot solution was poured into 230 to 300 ml
of water, filtered into a 300 nl volumetric flask and 60 al of hydrochloric
acid of 1.18 sp» gr. was added} eater was then added to the mark. 100 ml were
removed and titrated with 0.1 H sodium nitrite uaiag tropaeolia as the indica-
tor (6) to determine tha total amouat of amino-S according to the following
formulat
-------
a 162*a
10 000
where: a is the volume in ml of 0.1 H of the nitrite solution used in the
tit rat ion.
The bromination was carried out as follows: to 25 ml of the solution
taken from the volumetric flask 0.1 N solution of bromide-bromate was added
until the color of the solution became distinctly yellow; then the flask was
closed with a ground-to-fit stopper and sealed} the solution was left standing
for 30 minutes. For the determination of excess bromide-bromate 2 g of potas-
sium iodide were added and left rest for 5 minutes; the iodine was then titrat-
ed with an 0*1 N thiosulfate solution using starch as the indicator.
The above described nitration and the reduction reactions resulted in the
appearance of five dichloraniline isomers. Amines resulting from bromination
of m-dichlorobeuzene yielded monobroadde derivatives and amines from o- and n-
diohlorobenzene yielded dibromidc derivatives.' The content of dichlorani lines
obtained from o- and n-dichlorobanasne expressed in grams, were computed on the
basis of the bromide consumed in the titration, according to the following
formulas
8
°
^ Jtt
2 20 000 100
where: V is the volume in ml of 0.1 5 solution of bromide-broiBate consumed in
25
the titration* TTT~ is the ratio of the volume of broainated solution to the vol-
ume of diaaotiaed solution in al.
The amount of dichloranilines in g obtained from o-dichlorobensene can be
computed from the following formulas "
3 - — S
100 D2
The percent content of &-dichlorob@nsene in the mixture equals tot
3r100 , 100
s 25
Sine® the content of n-dichlorob®nz@ne can be determined by its solidifi-
cation point, the content of c-diehlorobenzone can be computed on the basis of
th@ difference. --
The described method was checked with artificially prepared mixture* of
pure diohlorobansene iecaera. The results presented in Table 2 show that the
error in the determination of the contents of each i&oa&r wao less than IS of
-49-
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the sum of the isomera. Accordingly, the results indicate that the bromometrio
method, which was used for the determination of the meta-isomers in a mixture
of isomers of substituted amines, some nitro-ooapounda and phenols of the ben-
zene series, can also be used in connection with compounds originally having
no amino-, nitro- or ory-groups.
Such a method, can be used in the determination of dibromidobenzene isomers
and other substituted compounds which can be nitrated and reduced without dif-
ficulty as is the case tith dichlorobensene.
Table 2.
Checking the methods'- with the aid of artificial mixtures.
Dichloro^ensene
taken xn %
o-
IUO
. —
0
0
0
35,4
28,9
9,«
9,7
29,2
n-
0
100
0
96,4
93,3
64,6
71,1
80,8
84,9
41,0
M-
1).
1)
10()
3,6
6,7
0
0
9,6
5.4
29,8
Dichlorobensene
found in %
o~ .
99,8
—
—
0
0
35,4
28,4
10,0
10,2
29,2
n-
—
99,9
—
96,4
93,4
64,3
70,9
80,9
84,9
41,0
M-
99,4
4,3
6,6
0,3
0,7
9,1
4,9
29,8
Da t ermi nation
error in >»
' o-
-0,2
—
0
0
0
—0,5
4-0,4
+0,5
It
n-
—
-0,1
0
+0,1
—0,3
-0,2
+0,1
0
0
M-
. —
— 0,
-------
Bibliography.
1. Van der Linden T.. Rec. Irav. rhim. 30. 305 (t8tl).
2. 3 B Ji b 6 e p M a 11 T. B. u F o p n a H T. H.. Amui.-Kpar. upon. 5, 385
:;. T a k a b a s h i T-., K. i ra o t o K.. Y n m a il u T., J. Clicin. Sor. JapaH, ImL
Cbem. Sect. 54, 427 (1951).
4. Francis A. W., 11:11 A. J., J. Am. Chcm. Soc. 46, 2498 (1924).
5. e,i o g o B B. n. H C n p M c K o B A. A., Upon. opi. XIIH. 2, 101 (1936).
(i. n o p a H - K o m n n A. E. n M e p B n n <• K a n .'1. H., AHn.i.-Kpac. npou. 3,
399 (1933).
A Method for the Determination of Phytoncldes in the Air.
57
Yu. V. Ignatovich and X. M. Epstein.
Kiev Institute of Medicine.
195-198.
Ho quantitative methods are available for the determination of phytoncide
concentrations in the air or for .measuring doses under experimental conditions.
Therefore, phytoncide concentrations used experimentally cannot be studied on
a comparative basis with phytoncide concentrations found in the proximity of
live plants. The method used here in the qualitative .and quantitative deter-
mination of phytoncides is based on the principle of magnetic and dielectric
medium permeability. It is well known that the optical index of refraction is
determined by the magnetic and dielectric medium permeabilities. Magnetic per**
usability of most substances approximates unity, aheroas dielectric permeability
varies within wide Holts, depending upon the structure or polarity of the mol-
ecules of the substance. Polar molecules increase dielectric permeability and
with It the index of. refraction. With these considerations in mind determina-
tions were made of changes in tha index of refraction caused by the phytonoldQS
and their concentrations in the air computed accordingly. Changes in the ro-
fractioa Indexes of water or air doe to the presence of phytcncides cere deter-
With ti*e cooperation of Y* B. Kendratenko and Ta. I. Molyuk.
-51-
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rained with the aid of a Raleigh-type interferometer. Pith this instrument It
was possible to determine the difference in the refraction index of the two
media with an accuracy up to 0*6 x 10 . According to reports found in the
literature this type of interferometer can detect 0*0l£ of hydrogen in the air,
0.032 of carbon monoxide, and 0.006* of helium* Studies were carried out as
followss Water in a Connay dish sae saturated with phytoncides of different
origin. Determinations were then made for changes in the index of refraction
using pure water as a control* Measurements were Bade employing 20 ma cham-
bers. The results shoved that garlic phytoncides changed the index by 1*3 x
10*5, etc.
For the determination of phytoncides in the air 10 - 15 g of leaves or
flowers from different plants were kept in a Tishchenko container of 330 ml
capacity, for 20 to 24 hours when the air became saturated with phytoncides,
The saturated air was blown through one of the 250 ml chambers of the inter-
ferometer while the second chamber was filled with pure air and the difference
in refraction indexes determined*
Studies were made of the volatile phytoncides of garlic, bird cherry flowers
and leaves, jasmine flowers, wormwood, strawberry, nettle, acacia leaves, and
pine needles* In all cases the optic density of the air saturated with pfayton-
cides differed from the optic density of pure air and at times to a considera-
ble degree, as was the case with pine phytoncidoa which produced a change
-4
amounting to 1.10 , Determinations were made of phytoncide concentrations
under natural conditions, that ie, in close proximity of plants in the woods
and flower gardens. In the woods the interferometer was placed into a rack.
The outlet of a 25 cm gas chamber was attached to the inlet of the chamber*
The glass funnel 'was brought close to a flower or a tree branch and the air
aspirated into the interferometer chanbor. The results listed in Tablo 1 show
that under natural conditions thsr@ vas a oaasurabld phytoacido concentration.
Phytoncidos of pine naedlos yielded the highest readings. Taste war® t&sn made
of the possibility to maintain constant pine phytoncide concentrations with the
aid of the interferometer for the laboratory study of their biological activity.
The effect of pine phytonoidos on the aalatio norve of a frog aas studied, since
«* H. Epstein, B* Halyuk and V, Kon&ratenko demonstrated that phytoncidee of
pine needles, bird cherry, garlic and other plants caused changes in.the bio-*
currents of the ociatic nerve, The studies were made with the aid of on appa-
-52-
-------
Table 1.
Concentration of volatile phytoncides in the air immediately
surrounding Plants
Date of
test
25 v
9 VI
9 VI
9 VI
8 VI
8 VI
14 VI
14 VI
14 VI
25 x
| | Interfere- ;
: Plants studied ; meter height j
I | in meters ,
Li lac , flowers
Jasmine, bush
Dianthns
Rose
Pine tree, in woods
12 years old
Ditto
Ditto
Ditto
Pine tree, in woods
16 years old
Pine tree, in woods
12 years old
2.5
0
2.5
0
6.0
0
I Number of j f la*ive ,re"
divisions ****** i»-
j | dex X10 '
7-8 ^
8 -10
10 -12
5 - 5.5
8.0
0
12.0
12.0
16.0
0
4.2 - 1.8
4.8 - 6.0
6.0 - 7.2
3.0 - 3.3
4.8
0
7.2
7.2
9.6
0
ratus scheaatlcally illustrated in Pig. 1. It consisted of a 60 li container
(b) filled with pine needles and a vessel (S) equipped with non-polarising
electrodes* the sciatic nerve, covered at one end, was suspended over the
electrodes? the interferometer (I) was inserted between the container with the
needles and the electrode chamber. The electrodes were connected to a potentio-
meter from which tho current flowed to a mirror galvanometer. Pure air was
pumped into the container holding the pine needles, forcing the phytonoido-
saturated air out of the container. The air passed through the interferometer
into the electrode chamber where it
cane in contact with the sciatic nerve.
Tho interferometer served to maintain
tha constancy of the pine phyfeoncide
concentration. The interferometer
could also be attached to the outgoing
outlet of chamber (S) and the pine
phytoncides aspirated through the ap-
paratus. Measurements of the Efl? gen-
erated within the nerve were taken
* every 3 minutea.
-53-
-------
o
-p
•H
4*
OS
O
0
O
O
O
A
••»
C
:
C
o
£
o
g
*
O
t*
-H
O
Time in minutes
Fig/ 2. a - 20, b - 35, 0-85 divisions
In Pig* 2 are graphi-
cally presented the re-
sults of three experiments
performed with different
pine needle phytoncide con-
centrations. The nerve
currents vere studied at
concentrations close to
those observed in the pine
woods. For convenience the
IiJ£P is recorded in percent.
The initial 3£F vas desig-
nated as 1OO£. The course
followed by the curves in-
dicated that the drop in
of
vas proportional to the concentration of the phytoncides.
The method here described should make possible the study of bic— effects
controlled phytoncide concentrations.
A Rapid Method for the Determination of Nitrogen Oxides in the Air.
*
L. A. Hokhov and V. S. Shalturin.
Laboratornoe Dale, Vol. 4, Ho, 2, 26-27, 1958.
The basic reagent used in the rapid method for the determination of oxides
of nitrogen in the air (l) is the Grias-Ilosvaya solution which is a mixture
of sulfanilic acid and c-naphtbylamine dissolved in acetic acid. Quantitative
determination of nitrogen oxides in the air were made with the aid of a special-
ly prepared standard color scale* In determining nitrogen oxides some authors
(2) used tube indicators of silicagel in an aqueous solution of diphenylaoine,
-54-
-------
alcohol and sodium chloride, or solutions of a-naphthylaralae and sulfanllic
acid as the reagents* The amount of nitrogen oxides was proportional to the
length of the colored column of the tube indicator or to the intensity of the
developed gel color* For rapid determination of nitrogen oxides in the air,
Arnold and Hontsel (3) used filter paper moistened with an alcohol solution
of "bsnzidine. In the presence of nitrogen oxides in the air, the filter paper
acquired various blue shades.
In the course of this study it was noted that silicagelf treated with ban-
Bidine-hydrochloride, fJ-naphthol, HiCl.» and dried, changed its color in the
presence of nitrogen oxides from the initial white to a stable red, the in-
tensity of which was proportional to the concentration of nitrogen oxides in
the air. The primary reagents used in the reaction were employed for the
production of an aso dyet in the presence of oxides of nitrogen benaidine-
hydrochloride produced a diaaoaiua compound; and p-naphthol was used as tbo
aso componentj nickel chloride acted as the catalytic agent.
Prepare the indicator using the following solutions! l) a saturated al-
coholic solution of benzidine chloride of analytical quality; 2) & $% alcoholic
solution of p-naphthol (c.p.), and 3) an O.l£ alcoholic solution of nickel
chloride (c.p.). To 0.5 g ailicagel prepared tgr the method described (4), add
0.2 ml of the benzidine-hydrochloride solution, stir until the silicagel appears
to be dry; then add 0.1 ml of the alcoholic solution of p-naphthol and again
stir until the mixture becomes fluid; add 0.1 ml of the alcoholic nickel chlo-
ride solution and again stir to gel consistency; the gel indicator is now ready
for use in making nitrogen oxidas determinations.
For the determination of nitrogen oxides a glass tube is used one end of
which is tapered and heat sealed. A wad of glass wool or of cotton is inserted
into the tube and gently packed down with a glass rod) this is followed by a
3 m layer of heated quarts sand, a 2 cm layer of the indicator followed by
a&ot&sr 1 cm layer of quaxts sand* The material is packed down V holding the
tube vertically and gently tapping it upon a table. A final cotton plug is
then introduced and the tube is heat sealed so as to create some vacuum in the
tube.
IB air analysis both ends of the tube are opened, and 100 ml of the tested
air is aspirated froa the wide to the narrow end of the tube within 30 seconds.
At the expiration of one or two minutes the color developed in the tube is coa-
pared with the standard scale, which IB prepared aa follows* use air mixtures
-55-
-------
which contain exact concentrations of nitrogen oxides in steps ranging from
0.0005 to 0.1 mg/lij aspirate through individual indicator tubes respectively
and check against the Grisa-Ilosvaya reagent for accuracy. The colors developed
in the standard tubes are then reproduced on strips of paper by an artist} the
^strips are carefully marked for the oxides of nitrogen concentrations they rep-
resent and stored.
Tests were made for the sensitivity of the tube indicator method} the re-
sults are shown in the following Table. The original while color of the control
tube indicator remained unchanged after exposure to oaone, hydrogen sulflde,
ammonia gas, carbon bisulfide, vapors of hydrochloric acid, ether and alcohol.
Average sensitivity of the indicator equals 0.0005 mg/li and the precision is
±3.5*.
Average results by the two methods studied
Oxides of
nitrogen
in mg/li
0.
0.
0.
0.
0.
0006
002?
0053
048
12
Determined by
Griaa-Ilosvai
test
0.0006
0.002 - 0.003
0.005 - 0.006
Precipitated
Precipitated
1 Determined by
the indicator
; tube method.
0.0006
0.003
0.005
0.05
0.1
Bibliography.
1. Shershevskaya, 1., Vorontsova, E. V. kn., Zhitkova, A. S. Rapid methods
for the Determination of Noxious Gases and Vapors in the Air of Industrial
Establishments. U-L, 1946, p. 45*
2, Plachenov, T. G.f Filyanskaya, Ye. D. Certificate of Authorship Bo. 99872
(449189/3765) dated 26 November 1953.
X, Arnold, C., Mentael, C. Ber. Deutsch Chem. Ges., 1902, Bd. 25, 3. 1902.
4. Mokhov, L. A.f Demidov, A. V* Lab. Delo, 1957* Ho. 1, p. 48.
-56-
-------
Simultaneous Determination of Carbon, Hydrogen and Hitrogea.
*
V. A. Klimova and 6. ?. Anismova.
H. D. Zelinski Institute of Organic Chemistry, Academy of Sciences, U.S.S.R.
Invest. Akad. Sank, S.S.S.R., Otdel. Khiin. Hauk, So. 6, 791-792* 1958.
Hext to carbon and hydrogen, nitrogen is most frequently determined in
organic analysis. Despite the desirability of determining nitrogen simultane-
ously with carbon and hydrogen no rapid and reliable method has been developed
for the purpose. The proposed method is based on pyrolysis of the tost material
in a rapid current of oxygen in a vacuumated combustion tube. The carbon and
hydrogen are oxidized quantitatively to C0? and water (l), while the nitrogen
is liberated partially in the form of oxides, partially as free nitrogen (2 -
3)* The formed water, nitric oxide, and carbon dioxide are absorbed respec-
tively by an anhydride, a solution of potassium bichromate in sulfuric acid
and by ascarite in silicagel (4 - 5)* ?ne free nitrogen mixed with a largo
quantity of oxygon is drawn over a copper preparation which absorbs the oxygen,
after which the nitrogen is forced out by CO- into an asotometer containing a
solution of EOH and is determined quantitatively. The total nitrogen content
in the test substance is arrived at by adding the H of the oxides and the free
nitrogen*
Pure oxygen was obtained by catalytic decomposition of perhydrol in the
presence of cuprlo oxide* The oxygen was collected in a gasometer over a satu-
rated solution of sodium chloride, A single combustion operation required 300
ml of pure oxygen. In control experiments this volume of oxygen yielded 0.032 -
0,037 ml of uhabsorbed gas. The rate of oxygou f Icra- was 20-25 ml/min. The .
copper mixture was prepared by adding 300 ml of 40^ solution of HaOZ to 130 g
of OaCl.SHO dissolved in 1200 ml of water at 60°, Fifteen g of silicagel
dried for 2.3 hours at 200 was added, th& mixture stirred and left rest over-
night. The foxtsad reaction maos was washed to neutral pheaolphthaleine reaction,
filtered, and desiccated for 6-7 hours at 200 with occasional breaking up
of luaps« It was then ground to a ponder and reduced is a current of hydrogea
at 230 to 280 which is tbs t?orkicg t&3pe?at«ft?e of the reduced copper prepa-
ration, at such teatperature it will absorb 100 al of 0^ par g. The final toot
-57-
-------
is aad« with the apparatus used in the rapid microdetenaination of carbon and
hydrogen. A three-way stopcock connected to a Mariotte flask and a glass tube
filled vith the copper reagent was attached to the end tube. The tube vita
the copper reagent h&s a side outlet which is connected to a Xipp generator*
the end tube drawn to an angle of approximately 120 is attached to the stop-
cock of the a&otometer as shown in the illustration*
pr ••;• ':±_ "'^. :::::5*»*x—-
"^j;^ — Q^-
Apparatus for the sisultaneous determination of C, H and
1 - Combustion tube* 2 - electric heater* 3, 4, 5 - water,
nitrogen oxide and carbon dioxide absorbers* 6 - closing
tube; 7 - three—way stopcock* 8 - tube containing copper
preparation* 9 - electric heater* 10 - nitrogen gas aster;
11 - aspirator*
The analysis is made as follows! place 2 - 8 mg of the tested substance
into the combustion tube* 400 - 300 ml of oxygen are passed through the appa-
ratus to remove the air present in the tube. Connect the tube containing the
copper reagent to the Kipp generator; check against air leakage as indicated
by tiny bubbles appearing in the azometer. Close the stopcock of the Kipp gen-
erator* connect the end tube with the copper reagent and start the combustion
(pyrolysis) (l). The combustion is accomplished in 20 - 25 minutes. When the
combustion is completed the absorption tubes are weighed, the nitrogen is forced
into the axooeter and its volume recorded. The total time required for a com-
•
plete analysis is 60 - 65 minutes. Several nitrogenous compounds were analysed
by the proposed method* the data are presented in the Table.
A method ia described for the simultaneous determination of carbon, hy-
drogen and nitrogen by pyrolyeis of organic subetanoes in a stream of oxygen
passing through & combustion tube. The carbon and hydrogen are determined in
the usual way* total nitrogen is determined by adding the free nitrogen and I
of the formed oxides.
-------
Table,
PS
4»
O
£
1
2
3
4
5
Fornula
C,II«ON.
C.H^OHXNO.},
C.H.— C— C.II.
1
N-NH-C.H.K. QHEJIHT. IHMHH, 6, 4, 230 (1951).
5. B. A. KjiHMOBaaK. C. Safipoaaaa, Has. AH CCCP. OTA. MM. H.
-59-
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A Hygienic Evaluation of Highly Dispersed Molybdenum Aerosol.
0. Ta. Hogilevskaya.
From the Department of Labor Hygiene of the let Moscow Order of
Lenin Medical Institute.
Gigiena i Sanitariya, Ho. 3, 23-27, 1952.
The use of molybdenum in quality steel production created a labor-hygiene
problem in as much as molybdenum and its compounds find their way into the air
during metallurgical processing) therefore, its possible effect on the organise
was studied*
Knowledge of some physical properties of molybdenum enabled this writer to
establish the following: owing to the high cup. of molybdenum (2,690 - 2,840°),
it did not exist in vapor form at temperatures of 1,500 - 1,600 prevailing in
electric metallurgy* Ifolybdenum is easily oxidized at 600° forming HoO, the
jfc
vapor tension of which increased with decrease in temperature and at 1,155
reached 760 ma of mercury. During processing molybdenum found its way into the
air chiefly in the fora of a highly dispersed HoO, aerosol. Investigations were,
therefore, made to determine the content of molybdenum trioxide in the air of
an experimental workshop during smelting of alloys containing molybdenum in
furnaces of 40 kg capacity operated by high frequency induction currents.
Air samples were collected directly above the crucible furnace and at
levels of inhalation by the aspiration method, using adapters filled with hygro-
scopic cotton, at rates of 10 - 12 li/raln. The cotton was previously boiled in
25 ml of 5£ soda solution. Molybdenum was determined, after acidifying the fil-
ter retained material with 40£ sulfurio acid, by H. V. Hifontova's thiocyanate
method. The complete solubility of molybdenum trioxidd in 356 soda solution waa
first checked by precision weighing. Analyses were rimdft with different concen-
trations of molybdenum in the alloy. In some cases molybdenum was used in the
form of t errOHOiybdenumj some test* were made by reoelting alloy waste or scraps
containing molybdenua.
In the following Table results are shown obtained from air samples tafcen at
different stages of smelting extending over 1 hour; the alloy contained 4% mo-
lybdenum. The data listed in tie Table show that th® penetration of
-60-
-------
into the air ino^e^JM^^a^ajlly starting at the time when the ferromolybdenuB
and molybdenxm icrVp* were added, reaching a marH«nm at the middle of the
"5* * ^&Z'* ' - - •-
smelting stage aol ri^Hg toward the end of it; in case of waste remelting
this occurred soon after the Ho was added* In the case of continuous furnace
charge smelting an intensive liberation of molybdenum persisted throughout the
duration of the process. The data clearly indicate that in the smelting proc-
esses molybdenus trioxide found its way into the air of the workshops and that
liberation of molybdenum trioxide varied at different smelting stages, libera-
tion of molybdenum in the air started immediately after the introduction of
ingredients containing molybdenum, its presence in the air came well into evi-
dence at 600 - 800°, that is long before reaching the melting point. Tests
were made for the determination of a parallelism which may exist between the
molybdenum content in the alloy and its concentration in the air. Twenty air
samples were collected in the course of processing of one alloy containing 4%
of Mo and 20 air samples during the processing of one alloy containing 17£ of
molybdenum* In the first case tha average content of molybdenum trioxide in
. 3 ,3
the air around the furnace was 1.39 nfl/m , and. ia the second 5*4 mgym , reaching
at times 7 to 14 og/B , showing that the content of molybdenum trioxide in the
air varied with the content of molybdenum in the alloy. The mixing of smelted
metal and exposing of fresh melted metal surfaces increased the liberation of
Ho into the air, la the resulting of alloys containing molybdenum, the libera-
tion of molybdenum ceased and molybdenum trioxide was not found in the tests*
HoO^ liberation reappeared during pouring and casting* when its concentration in
.*..... \
the air rose to 0*5 og/m .
HnO* content of air over the crucible at different
smelting stages
Molybdenum concentration in mg/ra
[Beginning of
f f
• Nature of *j m ( melting
| process ,®j(^ - *5
Hidstage of Finish of
malting melting !
(15.- 25 min)(lO..- 15.minJ
ih
if
'He-melting. _ ! i
or waste and '
scrap con- •• 1 - ,! :
itainingHo .30 0.1J0.4 0.19 0.1 4.8 JL.15 ; 0 0,16 0.02
Blaat fur- ; J
;nac« melting 18 0.0 0.1 0.02 0.1 3.7 0.84 0*2. 1.0 0.75
-61-
-------
Thus, in quality steal production, the liberation of molybdenum triood.de
into the air increased with the increase in the content of molybdenum in the
alloy, it varied with the melting stage, increased during sizing and stirring
of melted metal layers and their contact with the air. Molybdenum trioxide
was found not only in the air above the furnace a but also at the inhalation
level.
o
Even with an exposed surface as small as 150 * 180 cm molybdenum liber-
ated into the air reached a concentration of 0.22 mg/m , and in some tests at
the level of inhalation 0.4 to 0.5 m£/a J i* is quite conceivable that the
concentration of Mo in the air was directly proportional to the exposed surfaces
of the melted alloy.
Having determined the concentration of highly dispersed lioO. aerosol during
its processing, the next task was to establish the effects of these or higher
concentrations on experimental animals. For this purpose HoO, aerosol was ob-
tained by oxidation of metallic molybdenum with the aid of an electric arc in
a combustion chamber of 340 li capacity provided with a helical air mixer. The
molybdenum in a form of a homogeneously powdered mass suspended in a solution
of sodium silicate was placed over the electrodes in layers 2.0 - 2.5 ES thick.
(See Note l). The current was turned on after the applied layer became dry.
A constant molybdenum trioxide concentration was attained as follows: the cur-
rent was turned on and off intermittently at 10 minute intervals over a period
of 2 hours. Tests made in the course of the 2 hours showed a reasonably con-
stant concentration of HoO* varying from 3 to 10 mg/m with 4.9 mg/a a» the
average. With a layer of HoO, 4 mm thick it was possible to attain air conoen*
- - ^ ^ .
trationa ranging between 40-60 mg/m . $0£ of the aerosol particles were less
than 1 (i in diameter. Inhalation exposure tests were made with white rats in
two series* 1) acute and 2) chronic. In the acute experiments rats were ex-
posed for 2 hours to MoO, concentrations of 64 mg/ra . Ho notable symptoms of
intoxication appeared during tha exposure nor were asy symp£o&s of intoxication
observed in the aniffials 2 weeks later} the «sight of the exposed animals in-
creased in a way comparable to the control animals. Two weeks later the animals
were sacrificed. Macroscopic examination of the organs rovealed only an uneven
l^ng hyperemia. Hoaevor, hiotologioally organs of th* experimental animals
showed marked pathczaorphological changes characteristic of intoxication. Tha
liver showed signs of necrobiotio processes in the fozsa of poorly staining
-62-
-------
nuclei, photoplasnic granulation of liver cells and signs of liver regeneration
in the form of binuelear cells with hyperchrooio nuclei (Pig. l). The heart
showed a mild hypereaia, parts of the muscle fibers were intensely violet in
color, their nuclei were of a similar size and hyperchromic. In the kidneys
there was a swelling of the. epithelium of the convoluted tubules, protoplasm
granulation and poorly staining nuclei. The lungs showed foci of vicarious
emphysemay peribronchial infiltrations and polyemia and interstitial pneumonia
with symptoms of lung dystelectasie in spots* The histological changes found
in the livor and in the heart pointed to the fact that dyctrophic processes
were present in the cells, reaching the necrobiotic stage in the liver. At
the same time, regenerating processes developed; they were particularly pro-
nounced in the liver. (See Hote 2). Thus, it has been established that a
single exposure of rats to MoO-, concentration of 64 ffiS/ca produced dystrophic
processes in the heart, the liver, and the kidneys. The mechanism of toxic
action of MoO^ aerosol has not been established*
Chronic intoxication was attained by exposure every other day for 2 hours
during 2 months to concentrations of molybdenum trioxide varying between 3 to
10 mg/m . During the entire experimental period no signs of pathologic changes
were observed in the animals. The animals gained weight at the same rate as
the controls. Two months later the aniaals were sacrificed. Macroscopic ex-
amination of the organs revealed only an uneven hyperemia of the lung and a
slight hyperesia of the liver in some instances.
Microscopic examination revealed a definite picture of pathomorphological
changes resulting from the toxic effects of the highly dispersed HoCK aarosol,
even in low concentrations. They consisted of livor dystrophy, heart and kid-
ney spelling, protoplasmic granularity and poorly stained nuclei. Sections
stained with sudan 3 revealed foci of adiposio in the form of small droplets.
These phenomena aero particularly pronounced in the liver which alec ahowed
the presence of young binuclsar cells with hyperchrosaic nuclei indicative of
regenerative processes. (Pig. 2). There was a moderate heart edema and a
basophilia of some muscle fibers (Fig. 3). Evidence of interstitial pneumonia
appeared in cany oases* There was SOBS thickening of the alvsolar walls (Fig.
4)j dystelectasis (?) end vicarious emphysema appeared in spots.
The results presented show that the effect of molybdenura trioxide aerosol
saa not limited to local changes in some organs. As is the case with any
-63-
-------
Fig. 1.
Fig. 2
Fig. 3.
Fig. 4.
toxic agent the effect of KoQ, was general and produced a number of functional
shifts in the organism, vhich could 'be brought into evidence toy sensitive
methods of investigation, which will be discussed in a forthcoming report.
1* In electrometallurgical processes ty which quality steel is produced
with ferromolybdeuum and molybdenum steel scrap the highly dispersed aerosol
of molybdenum trioxide may find its way into the air of workrooms. The aerosol
•
concentration in the air varied directly with the content of molybdenum in the
furnace charge of the revolting scrap or alloy and with the melting phase)
*
stirring of the molten layers exposed new surfaces and increased the MoO, emis-
sion into the air.
-------
2. Experimental exposure of rats to the toxic effect of highly dispersed
HoO, aerosol shoved that repeated inhalation of MoO, concentrations of 3 - 10
\ '
mg/m produced dystrophlc changes of the internal organs, mostly in the liver,
heart and kidneys. Analogous changes in rats' organs developed as early as 2
hours After inhaling the UoCK aerosol in concentration of 64 mg/a *
3. Results of this study indicated that finely dispersed aerosol of mo-
lybdenum trioxido formed in processing alloys containing molybdenum were highly
toxic. .
Hotas.
Note 1* The method here described was used in toxlcological studies of
the highly dispersed aerosols of cadmium, vanadium and other metals. In the
electric arc flamo gaseous components of nitric oxide and osone were formed*
For purposes of control rats were exposed in the same combustion chamber to
the effects of the electric arc alone. Observations were all negative.
Note 2. Observations and interpretations of pathologic developments were
made in cooperation with S. M. Serebrenikova.
A Comparative Study of Experimental and Theoretical Atmospheric Pollution
Concentrations Resulting from Low Level Bnission*.
P. I. Andreyev.
Oigiena i Sanitariya, Ho* 9, 17-20, 1952.
The following formulas for the computation of expected concentrations of
gases discharged by industrial establishments were derived on the basis of the
theory of turbulent diffusion in the atmosphere! (l)
For gaseous pollutants cosing from smokestacks!
_
nM.2000 ." <* [1]
-65-
-------
For unorganised discharge of gases into the atmosphere t
Af'200° e [2]
where i
K • output of source of pollution in g/sec;
X • distance in meters from the source of emission to the point of ob-
servation on the lee side}
K. - output of a linear source of pollution in g/seo/m;
V m velocity of wind in m/seo;
H • effective height of emission in m. equal to h +• A h, where h is the
height of the discharge above the ground, or the height of a chimney
in the case of organized discharge, and Ah is the rise of the stream
above the mouth of the chionoy, which is a function of the exhaust
velocity and of the wind velocity impacts;
C VC - coefficients of horizontal and vertical dispersion respectively. At
n m 0 the coefficients are indeterminate;
Iw • IB /sec of air mixed with gases emitted by the smokestack;
n - meteorological factor the value of which depends on the atmospheric
temperature gradient}
i) » formula correction factor, which accounts for the duration of sample
collections}
C m gas concentration at ground levol in mg/n »
^B ^^ *^ *^
Fornula [1] is for the calculation of groaad level gas concentration along-
the axis of a flou coming from a pointed soured. Formula [2] is for the cal-
culation of ground levol gas concentrations e&anaiing frccn a linear source* la
the case of pollutants emitted by a smokestack the wind velocity in formula [l]
can be regarded as equal to that found 10 m above the grouad, which is the
standard height for measuring wind velocity at meteorological stations. la
determining gas concentrations coming from ground level sources, the wind ve-
locity can be regarded as equal to that found 1*5 * 2 a above the ground. For-
mulas [l] and [2] are applicable to the determination of theoretical concentra-
tions of gases and highly dispersed dust*
A comparison of theoretical ccac cat rations computed for higa smokestack*
by Eoans of foEKala [l] with the experimental data was presented in publication
-66-
-------
(1) previously referred to. A similar comparison for gases of low level die-
charge is of equally great interest. Such a study was made by the Sanitary
Sygienio Institute in 1950 in the vicinity of a soot producing plant (2).
The discharge of soot from the factory smokestack 25 m high (h - 25 in)
into the atmospheric air during tho study averaged 308.92 kg/24 hour, t,r IT •
B
3*75 g/sec and 17*24 kg/24 hour coming frost the shop windows on the assumption
that the total extent of the windows was 20 m long, they have H. - 0,01 g/eoc/0,
The average wind velocity during the study was 2.3 n/sec. This value of
wind velocity should be substituted in formula [2j since the unorganized dis-
charge pollutants descend within the turbulence zone behind the building and
the washing away of the gas flow would take place close to the ground, or
h » 0.
In computing pollutant concentrations discharged froa the smokestack tho
measured velocity can be derived with the aid of the following fonaulat
where t
V. • average wind velocity as determined during the experiment at an as-
sumed height of 2, * 2 mf
x « uneveness of ground surface assumed to be « 0*1 n. The wind velocity
at Z • 10 m above the ground, if computed by forncla [3], would be
3.5 m/8eo*
n a may be assuz&d to equal aero, since the ©sporicsnts extended ovar a
long period of time.
The value of L_ in tha denominator of foamila [1] can have considerable
effect on the computed values of concentration only when the voluxss of gae-air
mixture is great, as is the case in viocoso silk raaraifacturing plants. In the
case under consideration the value of Lw can be taken as aero.
u
Experience has shown that where gases are discharged from smoksatac&s .
with h > 50 m and with n - 0, the values of coefficients C and C became
C » C L • 0.05. However, in the given case, on the basis of Teverovskii's ex-
periments, the values of these coefficients can be assumed as C - C ' * 0.1.
-67-
-------
Formula [l] ie for the computation of concentration changes along the axis
of the flow. Therefore, for the comparison of the theoretical concentration
values with those obtained experimentally, it was necessary to obtain the av-
erage of the maximum concentrations. In the case of gas dispersion correction
factor T) at 40 minutes of air sample collecting wad T) * 0*37* In the case of
dust dispersion the correction factor t) is a function not only of time, /\ tr
which is the duration of sample collecting, but also a function of the velocity
of falling dust in stationary air, and its value at identical At are always
greater than in the case of gas. For definite reasons the value of ij in this
study was taken as equal to 0.5.
In the Table below are presented computed concentrations and concentrations
obtained in the course of 153 tests made in the summer and in the fall, at va-
rious distances from the source of pollution. The values listed in the Table,
whether theoretical or experimentally obtained, represent totals of organized
and unorganized discharges.
Distance from the
source to the ob-
servation point in
m (i)
Computed concentra-
tions in mg/nH
Determined concentra-
tions in mg/BK
100
0.5
0,3
250
0.4
0.4
500
0.2
0.11
750
0.11
0.08
1,000
•
1
0.08
0.09
;
1,500
0.05
0.07
2,000
0.033
0.035
The data in the Table show a close agreement between the theoretical and
experimentally obtained concentrations in all cases except at the point located
at a distance of 100 m from the source of pollution. However, nc better coin-
cidence could have been expected in this case, due to the fact that wind cur-
rents carried off much of the soot at frequent intervals*
Furthermore, quantities of soot may cose from points of packing, loading
into railroad cars or trucks and during poking of furnaces. Quantities of soot
originating in the vicinity of the plant, as Just described, cannot be computed
by any formula.
A comparison of theoretical and experimental concentrations is shown in
the graph below* ~The theoretical total concentrations computed by fonaulss [1]
and [2] are indicated by a solid line. The broken line plot also indicates
theoretical total concentrations, but -ith the unorganised pollution concentra-
-68-
-------
0.8
054
0.1S
0.4Z
la w
If*
o BIS
o
012
,006
tions computed by formula [l], and with,
H - 0, as for a pointed source at ground
level. The plotted data indicate the ex*
perimental data*
The dash curve approaches the dots
representing the experimental data in the
proximity of the source, and recedes from
the experimental points as the distance
~i? § i? i § lxin from the source increases*
"* -• «*
The graph also shows that for x -
500 m and x • 750 m the theoretical curve passes close to the experimental data,
a fact which should not be dismissed as purely accidental* The explanation lies
in the fact that the formulas used were intended for the computations of ex-
pected gaseous concentrations* In dealing with hard particles, regardless of
how small in diameter, the fact must be remembered that ultimately their sedi-
mentation will take place, largely due to the coagulation of even the highly
dispersed particles. Some of the soot will settle in the proximity of the emis-
sion source* imparting to the theoretical curve a steeper slope. For this rea-
son the experimental points for x • 500 m and x • 750 m will tend to approach
the theoretical curve. This curve can be plotted if the dispersion composition
of the soot was determined at the sampling point* Unfortunately, the dispersion
composition of soot was not measured in the present investigation.
Thus, the formulas given for the dispersion of gases in the atmosphere ap-
plicable to oases of either high or low pollution sources will present an ade-
quate picture of the actual process of pollution diffusion in the atmosphere*
These formulae may be utilized in dealing with problems arising in planning pro-
duction and manufacturing plants and in conducting scientific research*
Bibliography.
1. Andreyev, P. I. Spread of Gases Extruded by Industrial Establishments into
the Atmosphere. led. Literatury po Stroitelstve i Arkhitekture, 1952*
2. Podorovskii, P. Ye* and Zykov, A. S* A Study of Efficiency of a Cleansing
Apparatus in a Carbon Black Manufacturing Plant and Spread of Soot Pollutions
in the AtmoBpneric Air*
-69-
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A Comparative Evaluation of Different Gravimetric Methods for the
Determination of Dust Concentration in the Air.
To. V. yhiifrhrlna and Te. I. Vorontsova.
Froza Moscow Regional Scientific fiesearch Institute of Sanitation and Hygiene,
saidi the Institute of Labor Hygiene and Professional Maladies, Academy of
Medical Sciences, U.S.S.H.
Gigiena i Sanitariya, Ho. 11, 20-25 t 1954.
In 1952 - 1953 the Committee of the Academy of Sciences of the U.S.S.R.
for the Prevention of Silicoaia ordered that a comparative evaluation be made
of tiie different apparatus and methods used in determining air dust concentra-
tion. The following organizations participated in the task: the Moscow Region-
al Scientific Research Institute of Sanitation and %giene| the Institute of
Labor Qygiene and Occupational Diseases, Academy of Kedical Sciences of the
U.S.S.R.; the Institute of Physical Chemistry, the Academy of Sciences of the
U.S.S.R. | the Institute "Nigriaoloto", and the Moscow Institute of Labor Pro-
tection of the All-Union Central Council of Trade Unions.
Modifications of the gravimetric method with the use of cotton filters,
glass vool and filter paper were investigated. The vacuum and the Hot air
methods for drying of filter adapters were also re-examined. Ejector mine
aspirators, a mine injection aspirator developed by the Ministry of the Coal
Industry, and a rotary air (fan) blower aspirator developed by the Leningrad
Institute of Labor Hygiene and Occupational Diseases, were also checked for
their efficiency*
For this evaluation study a special dust chamber was constructed at the
Institute of Labor Hygiene and Occupational Diseases of the Academy of liedical
Sciences of tho U.3.3.E. Dust concentrations could be maintained within the
chamber varying from a for? to hundreds of milligrams per cubic meter in the
presence of a complex of air currents having a velocity of approximately
0.5 m/seo. ____
Fig. 1 is a schematic drawing of the chamber, the cross section of which
is hexagonal. Five sides of the chamber are made of glass and tho sixth is a
discountable wooden door through which instruments under study can be brought
in and the inside of the chamber cleaned* The cone-shaped roof or ceiling of
the chamber has three openings, oae for the admission of pure air, the other
-70-
-------
for dust-laden air, and the third for th* adjustment of necessary equipswnt.
A fan for mixing the air supplied into the chamber is installed in a conically-
shaped floor pan of the chamber* A detachable grating, for the equalisation
•>
of the air currents and for nor* even distribution of duet along the walls is
installed between the cone-shaped floor pan and the chamber proper. Ground
quarts or pulverised coal were used for dust.
Assembly A.
Ultramicro-
photometer
To dust suction
—— apparatus
To outside air
Pig. 1. Dust chamber
1 - Plowmeteraj 2 - Dust disperser ( see Assembly A)J 3 — Air
blower* 4 - Removable lidj 5 - Ventilator (fan)? 6 - .Electric
motor} 7 - Perforated bottom; 8 - Glass tube (gusiek)} 9 -Elas-
tic bandj 10 - Electric motori 11 - Projecting fastening
sorev} IT - Lathed roller; 13 - Steel spring}
14 - Bust distributor support.
**
^
Dust feeding into the chamber and the Maintenance of a desired concentra-
tion were accomplished by a specially chosen apparatus installed outside the
chamber. The apparatus consisted of a motor-driven air blower which supplied
either pure or dust-laden air, a dust disperser equipped with a sedimentation
tank and rubber hose, a snail motor with an attachment for th* dust disperser
end a shaker for better dust adzing, a flowneter to control th« air volume sup-
plied into the chamber, and a motor for the operation of the airing fan installs
in the conical floor pan*
-71-
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Control determinations were made for dust concentrations produced at vari-
ous rates of dust-laden air supplied into the chamber; the method of quantita-
tive dust dispersion was standardised so that the total volume of pure or dust-
laden air supplied into the chamber was always equal to the air volume removed
from the testing chamber. Thus, during the collection of two samples, each at
the rate of 15 li/min, 30 li/min was supplied into the chamber; if three sam-
ples 15/11 min each were collected, then 45 li/min was supplied into the cham-
ber during air sample collection, etc. This prevented the creation of sudden
pressure changes inside the chamber;
Depending upon the concentration desired, the rate of dust-laden air supply
varied between 2 to 8 li/min; additional pure air, the rate of which varied up
to 45 ii/min to maintain the "balance", was supplied by the air blower through
a separate flo%meter by-passing the dust diaperaer.
The air from the blower was fed to a T-coupling from which only that por-
tion of the air which was required for the experiment was directed into the
chamber; the excess air was diverted into the rocga. The total amount of air
directed into the chamber traveled along two branches of air conduits, each
passing through a separate flowmeter. One branch carried the air through the
dust disperserv the other carried pure air directly into the chamber.
Both conduits supplied the air into the chamber from above downward cen-
trally, thus causing the two air streams to descend into the conical floor pan,
shore the whirling fan mixed the air and forced the mixed air up along the cham-
ber walls at approximately 0.5 m/seo. The continuous operation of the shaker
provided a uniform supply of dust from the dust disperser. Two sedimentation
tanks, one outside the chamber and the other inside, the chamber located in the.
conical floor pan below the fan, a grate over the floor pan and the downward
flov of the air within the chamber all contributed to the separation of the
coarse dust particles or agglomerations of dust before they reached the operat-
ing part of the chamber. The ma-rlmnl size of the dust particles within the
working part of the chamber rarely exceed 5 H*
The dust concentration within the operating part of the chamber was deter**
mi&dd gravimetrioally on the. basis of three samples simultaneously obtained at
different points 18 to 20 cm from the inside surface of the wooden door. Tsn
holes were drilled through the wooden door which were closed by plugs, used to
hold permanent apparatus. Six of the holes of the same diameters were arranged
-72-
-------
In groups of three, In the upper and the lower third of the chamber door. Varl-
ou* instruments or adapters used in connection with gravimetric determinations
were introduced into the chamber through these holes.
V
Check determinations of dust concentrations within the chamber showed the
following: when dust-laden air was supplied at the rate of 2 to 4 li/min the
dust concentration inside the chamber varied from a few to tens of mg/m , but
never exceeded 60 mg/m . If the dust-laden air was supplied at the rate of 6
to 8 li/min, then the dust concentration within the chamber varied froa 100 to
1000 mg/m . The uniformity of dust distribution within the operating part of
the chamber was found to be adequate and varied between 10 to 20£ in cases of
low concentrations, and only in rare occasions was the variation as high as
Ihe total number of experiments was 120 and the number of air samples
tested was 120.
As previously mentioned, three types of gravimetric methods were investi-
gated! l) the cotton filter, 2) the glass wool filter, and 3) filter paper.
When filter paper was used, special adapters were employed which were developed
Jointly by the "Higrisoloto" Institute and the Institute of Labor Hygiene and
Occupational Diseases of the Academy of Medical Sciences of the U.S.S.R. Such
adapters found application in the mining industry because of the convenience in
obtaining samples of weighed dust for chemical and mineraloglcal analysis.
Fig. 2 is a schematic drawing of the adapter.
The filters were checked for possible passing through of dust particles
as follows: a, gravimetrically, b. by particle count. Cotton filters were
tested first} iu preliminsiy tests 1OO# dust retention was obtained as indicat-
ed by gravimetric determinations. In the second series of check tests, the
^
filtered air was analyzed by means of electron micro-
scope VDK. Samples were obtained froa the chanter
having a dust concentration up to 320 mg/a , at an
aspiration rate of 15 li/min. The percentage of
*
dust retained "by various types of filters and the
respective pressure dropa of tee filters are shown
Fig. 2. Institute Nigri- in fable 1.
zoloto filter paper The data prasentad in Table x &om that the
holder
1 - Funnel-shaped part; dust retaining capacity of cotton and glass wool
~f^pe^filter! **•!*•» determined graviaetrically reached 100 per-
-------
cent when the pressure drop was 150 ma of water; in the case of ash-free paper
filters at a pressure drop of 200 to 230 com of water and aspiration rate of
1^ li/min dust retention as determined gravimetrically was complete* Results
of electron microscope examinations substantiated the results. Some of the
particles in the filtered air observed by the electron microscope were of no
practical significance since they had no effect on the weight of filters*
TABLE 1.
Dust retention of different
Type of filter
Cotton
Cotton
Glass wool
Glass wool
types
i
i
of filters in relation
Pressure drop |
in mm water [
column i
100
150
100
150
to pressure drop*
Dust retention
in %
95 - 100
100
95 - 100
100
Ash-free filter paper
(blue ribbon) 200-250 100
Twenty-five experiments were devoted to taking air samples from the cham-
ber lay the three methods simultaneously at a dust concentration in the chamber
of 2 - 400 mg/ia * The results of 15 experiments thus conducted showed varia-
tions not exceeding 202. In the remaining 10 experiments at dust concentrations
of 2 - 10 mg/m , the variations ranged from 20 to 50£. The three types of fil-
ters tested showed variations above and below the average values. The varia-
tions in the values of dust concentrations obtained in this series of experi-
ments were the same as those resulting from sianilteneous sampling by the stan-
dard method using identical filters. Since the throe types of filters used
gravimetripally were of equal dust retaining capacity, it follows that any one
of them can be ueed in detexmining air dust concentrations. However, since the
pressure drop created by ash-free paper filter wao 200 - 250 mm of water and
of the cotton filters only 150 cm, it is clear that the use of the latter should
be preferred.
Recently different laboratories have been using the method of speed-drying
of adapters, because the standard method for drying adapters and filters waa
time-consuming and delayed the final results of investigations. • The method of
speed-drying adapters with cotton filters proposed "by H. I. Erman of the
Khar'kov Institute of Labor Hygiene and Occupational Diseases consists of a
-74-
-------
metal adapter holder which is placed into a drying oven usually pre-heated to
103°. The exhaust tube of the holder is connected to a flowmeter and a vacuum
pump by means of a rubber tube passing through a hole in the drying oven* Hot
air ia drawn through five adapters simultaneously at a rate of 30 li/min for
a period of 15 minutes.
In some laboratories adapters with glass wool filters are dried to constant
weight by bloving rood temperature air through the adapters* Results of such
adapter-filter drying procedures are shown in Table 2.
TABLE 2«
Effect of different procedures for drying filters to constant weight.
Type of filter
Drying procedure
Percent of filters
with constant weight
_
Hygroscopic
cotton
Hygroscopic
cotton
Hon-hygroscopio
cotton
Glass wool
Glass wool
In thenaodryer at 103 o" hrs*
and repeated 2 hrs*
Blowing air of 105° for 15
min. at 6 li/min
Blowing air of 105° for 15
min. at 6 li/min
Ditto
Blowing air of room tempera-
ture twice for 10 min. at
Hearly
H
M
n
n
100
50
40
80
60
Ash-free blue rib-
bon filter paper
Ash-free blue rib-
bon filter paper
the rate of 15 li/min
Kept in boxes in theraodryera
at 105° twice for 6 hours
Kept in boxes in thexmodryers
at 105° twice for 2 hours
70
40
The most reliable method of adapter-filter drying is the one specified in
5609-50 All-Union State Standards, by which hot air is blown through the filter
twice; by this drying method it is possible to prepare 50£ of adapters with
cotton filters and 6X# with glass wool filters* The hot air speed-drying of
non-absorbent cotton filters which theoretically should have produced the best
results actually gave results inferior to those obtained with absorbent cotton*
This may have been duo to the lack of uniformity in the quality of these grades
of cotton, or to the presence of Impurities which evaporated or were otherwise
driven off during the process of heating.
-75-
-------
Another method for obtaining a constant weight with, the aid of a vacuum
apparatus and which gave satisfactory results, waa the one proposed "by P. P.
Dorosh, of the Ministry of Metallurgical Industry. However, such vacuum ap-
paratus needs to be perfected by improving its vacuum creating capacity, by
re-designing some parts to fit standard adapters, by changing the shape of the
roof of the drying chamber, etc.
Among the new aspiration devices proposed for air sampling tests were made
with ASR-1, ASE-2 and a similar device developed by the State Hitrogen Scien-
tific Research Institute, Bach device consisted of a two-liter cylinder of
air under pressure of 200 atmj the cylinder is connected via a reducing valve
with an ejector. An ASR-1 flowmeter or an AER-2 volume meter or one developed
"by the State Nitrogen Scientific Research Institute is connected to the ejector.
The device can be used in taking samples of air through any of the filters
tested. A schematic drawing of the device A21-1 is shown in Figure 3.
Best results were obtained with AEH-1, which was tested under laboratory
and practical mining conditions. The AJSB-2 device and the one developed by the
State Hitrogen Scientific Research Institute, instead of being equipped with
f lowmeters, are equipped with volume
meters, a variety of differential mem-
brane manometers which require frequent
checking and recalibration. The maximum
volume of air removed from one cylinder
was 1,200 11, hence one cylinder with
air under 200 atsa pressure proved adequate
in instances where one sample of air was
taken with a dust concentration 2 to 10
mg/H , or 5 to 10 samples of air with a
dust concentration cf tens of nig/m or
higher. Spare cylinders of compressed
air or of inert gas should be kept in
reserve where large number of air samples
Ejector type of ndne aspirator AEH-1 are to "be removed.
1 - Compressed air tank| 2 - BSWO- A *°tary air blower equipped with
meter? 3 - rcduoerj 4 - connecting pn9tm<»eters developed at the Leningrad
valvef 5 - seconds neter; 6 - •^•o-
torjT - rubber tubef 9 - flowaeter Institute of Labor hygiene and Oocupa-
-76-
-------
tional Diseases was tested tinder laboratory and practical plant conditions*
This apparatus was designed for taking two samples simultaneously* After six
months testing under laboratory and plant conditions the reliable performance
of the apparatus was established* Its quantity production is recommended*
Conclusions.
1* Results of experiments indicated that the cotton, glass wool and ash-
free paper filters can be recommended for use in air sample collection for the
gravimetric determination of air dust concentrations* With a rate of air flow
of 15/li min the retention of dust was shown to be complete at a pressure drop
of 150 mm of water when absorbent cotton or glass wool filters were used, and
of 200 to 2^0 mm of water when ash-free paper filters were used. The use of
non-absorbent cotton can not be recommended because of the difficulty of drying
it to a constant weight.
2* The hot-air speed-drying for bringing air filters to a constant weight
proposed by M. I. Erman of the Khar'kov Institute of Labor Hygiene and Occupa-
tional Diseases, can be recommended if the process is performed twice*
3* Best results for drying ashless filters wore obtained with a three-
stage drying; one of six hours, and two of two hours each*
4* Under actual conditions of manufacturing it may not be feasible to
operate an electrically driven vacuum pump and air blowers or the ejector could
not be connected to an available source of compressed air) under such conditiom
use should be made of ejectors developed by the Ministry of the Coal Industry)
preference is here expressed for ejector AER-1.
5* Results of the rotary air blower developed at the Leningrad Institute
of Labor Hygiene and Occupational Diseases and which is equipped with pnoumo-
meters, demonstrated its good qualities and its quantity production is recom-
mended.
-77-
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A Comparative Study of the Retention Capacity of Different Filters Used in
the Gravimetric Determination of Smoke Suspended Aerosols.
E. V* Geraet.
The Gor'kii Scientific Research Institute of Labor Hygiene
and Occupational Diseases.
Gigiena i Sanitariya 23, No. 2, pp. 77-83, 1958.
Air samples for the gravimetric determination of a dispersed phase of
tcxic aerosols in industrial production establishments are usually collected
by the combined aspiration-filtration method and the material retained on the
filter dissolved in a suitable solvent and analyzed chemically. Cotton fiber
and paper filters have been used most frequently. Suitable porous glass fil-
ters can be used effectively for the separation of certain types of aerosols
and easily soluble air suspended substances. The size of the air suspended
particles is a determining factor in the weight of the material retained by
the filter. Highly dispersed smoke of lead oxide formed in the process of
smelting metallic lead and its alloys, oxides of zinc formed during brass
melting, oxides of manganese and of copper formed in alloy production, all
consist of particles 2p or less in diameter. This writer found no literature
on the subject of the comparative capacity of different types of filtering
materials to retain highly dispersed smoke, nor has he found any recorded
standard curves of part isle distribution according to size which could be
used as a basis for the recommendation of best suited filtering material.
For purposes of this study it .appeared essential to employ a smoke which -pos^
sessed most widely encountered characteristic physical properties in order
to obtain experimentally any desired concentration of smoke.
Burning tetraethyl lead in the blue flame of a Buns en burner offered the
simplest and most convenient method of obtaining dispersed lead which was
retained by filter paper. The produced smoke consisted of highly dispersed
particles of lead oxide. Fig. 1, on electronogram of such smoke, shows the
particles to be spheroids arranged into short chain formation. The desired
gravimetric concentration of lead oxide was obtained 'by regulating the supply
of the tetraethyl lead. The characteristics of the aerosols and their con-
centrations were established by ultramicroscopic (electron microscopic) ex-
amination and from these standard distribution aurves were plotted for aero-
sol (smoke) particles ranging between 0.02 to 1.5 I* in diameter. Gravimetric
-78-
-------
determinations of smoke (aerosol) retained particles were made "by a specially
designed method in the fonn of dithiosonate of lead. The sensitivity of the
method was 0.5 Y of Fb Per "test. Burning one drop of tetraethyl lead in a
chamber of 1 m produced a particulate concentration of 5 - 6 x 10 • p/ml, the
gravimetric value of which was 2-3 m§/m . Burning 4 drops in same size
chamber raised the particulate concentration to 2 - 5 * 10^ P/ml with a grav-
imetric equivalent of 12 - 14 mg/m . To obtain concentrations of the order
of tenths of mg/m the author performed his experiments 2-10 hrs. after cre-
ating the concentrations.
For the construction of the dispersion curve particulates of the lead ox-
ide were caught from the air by an electrostatic rod-shaped precipitator il-
lustrated in Fig. 2. It consisted of an inside rod-shaped electrode having
rows of perforations into which are screwed in magnets which hold screens
provided with films to catch the particulate matter for electron-microscopic
examination. The rod is fixed to a head made of organic glass (dielectric).
After the screens are properly arranged the rod is inserted into the electrode-
tube and is fixed centrally with precision. With the aid of a high tension
generator a 5 000 V negative potential is fed into the rod and the positive
potential is grounded. The aerosol is aspirated at the rate of 0.5 - 1.0
1/min along the narrow bore of the electrode. The particles settle in a layer
of even thickness, but without size differentiation. Aspiration should be
continued until 10 - 20 1 of the aerosol has been aspirated. The density of
the. material accumulated is first determined with the aid of light microscope
and again by the electron microscope, following appropriate size samples are
taken from each layer formed. Photographs were made at 50 kV »"d electron mag-
nification of 4 OCX) - 5 000 X. This was further magnified to 20 000 X. Upon
positive images particle counts are made on such positive prints with the
aid of counting chambers 1 n long and consisting of ten 0.1 u squares, with
the aid of which particles up to 0.2 \i can be counted. A counting chamber
consisting of multiples of the above can be employed advantageously. The more
particles are counted the more accurate are the results. Generally not less
than 500 - 600 particles should be counted, grouped according to size and the
curve of distribution plotted. An example of such counts is presented in
Table 1. Measurements showed that 95 * 97$ of the particles were cf a magni-
tude below 1 (I, the majority being between 0.1 - 0.6 p, (expts. 1, 2, 3).
-79-
-------
Fig* 1. Sizes of lead oxide particles obtained
ty burning tetraethyl lead.
Fig. 2. Electrostatic rod-shaped precipitator.
1-Preeipitator rod; 2-recess for screanj 3-joint boltaj 4-joint head;
5-high frequency negative lead terminal; 6-outside aleotrod«
frequency positive lead terminal.
-80-
-------
Different concentrations of lead oxide were created by the method de-
scribed, and the particulate retention capacity of filtering material tested.
Cotton filters with a pressure drop of 150 - 300 mm at aspiration rate of 15
1/min were tested. A filtering system was set up consisting of 4 and 3 adapt-
ers filled with hygroscopic cotton and connected in consecutive series. Grav-
imetric determinations for the amount of retained particulate matter were made
for individual filters. The results are presented in Table 2.
It was demonstrated that increasing the pressure drop of the cotton fil-
ter from 150 to 300 mm had little effect on the filter particulate matter re-
taining capacity. Aspiration of air having a 10 - 20 mg/m concentration of
lead oxide resulted in the retention by the first filter of 85^ of the parti-
cles by weight. As the particle concentration was lowered and the particle
*
size reduced the retention by the first filter amounted to only 6?%. A study
of the concentration count before and after a single cotton filtration by the
VDK ultramicrophotometer showed that the number of particles not held back by
the filter ranged between 11 - 24£. A study was made of the size of non—re-
tained particles with the aid of an electrostatic precipitator and electron
microscope. The results showed that all particulate sizes contained in the
original lead oxide smoke, ranged from 0.05 - 1»0 |i.
. 3. Organic glass (plastic) funnel-shaped
holder for paper disk filter.
Ash-free filter paper has been used freguently in practice and it has
been recommended in the past that the densest, blue ribbon paper be used,
-81-
-------
Table 1.
Results of particle counts for the construction
of size distribution curve,
lizes in
H
0.02-0.05
0.05-0.1
0.1—0.2
0.2-0,4
0.4—0,6
0.6—0.8
0.8-1.0
1.0—2.0
Total •
JSXpexruueub «u»
I
g*&
10
85
110
202
69
22
13
411
%
1.98
16,7
21.5
39.5
13.5
4.3
2.5
100
2
rifi1
o»&
•pflxS
•£"&
»
127
232
154
46
33
25
6
542
%
3,0
19.8
36.0
24.0
7.2
5.2
3.9
0.9
100
3
g^
8
82
167
88
32
11
20
408
%
2.0
20.0
40.7
21.6
7,9
2.8
5.0
100
Table 2.
Results of lead smoke retaining capacity of cotton filters
-0
0)
CO
COM
ore
+>
0)
OS
«H
150
150
150
JEO
^
•Hfc
V< -H
OOm
0>
t^TjdO
0.58
0.81
20.16
21.56
300 j 5.01
300 , 7.82
300
300
300
11.8
17.8
28,3
H .
o
PP
co3
fcS
-------
which la not always available. Tests were, therefore, made to determine the
retention capacity of other makes of ash-free filter paper. Pour types of
ash-free filter paper were obtained of which two were manufactured by the
D. I. Mendeleev Chemo-Technological Institutes white and blue ribbons, and
two "by the Zagorsk Filter Paper Mnfring Plant: red and blue ribbon. The
tested filter paper, 5 cm in diameter, was placed into a funnel such as shown
in Pig 3, and tightly sealed. The effectiveness of the sealing was first
tested. Each type of filter paper was tested for uniformity of construction
by studying 10 specimens of each lot and testing their drop pressure at aspi-
ration rates of 5, 10 and 15 1/min. The average results are shown in Table
3. Results showed that individual sheets of any lot had different pressure
drops. The average pressure drops of white and blue ribbon filter paper man-
ufactured by the Moscow Chemo-Technological D. I. Mendeleev Institute and of
the red ribbon, paper manufactured by the Zagorsk plant were almost identical,
but the considerably heavier blue ribbon Zagorsk filter paper had a pressure
drop approximately twice that of the other filter papers,
TABLE 3.
Pilter paper resistance in mm of mercury column*
TSJ-IA . s m j » lAspiration rate in liter per minute
Pilter paper grade . Trade mark .—«—= rrr -—«=—-c
t • j . Xv . Xj
Moscow D. I* Mende-
leev Cham.-Technol.
Institute White.ribbon . 14.6.., 31.0 46.0
Ditto Blue ribbon 13.0 31.0 45.0
Zagorsk make Red ribbon 14.0 32.0 47.0
Ditto Blue ribbon 30.0 65.0 92.0
In testing the filtering capacity of the paper filters two disks were
placed into the funnel, the required volume of air was then aspirated and the
quantity of lead retained by each of the filters determined. The results are
presented in Table 4. The results show that at aspiration rate of 10 - 15
1/min one filter paper of any of the brands tested retained nearly the entire
gravimetric quantity of the highly dispersed lead oxides. In most instances
the quantity of lead oxide aerosol caught by the second filter amounted to
tenths of a percent; and in a few isolated instances it amounted to 7.7S6.
-83-
-------
Control tests of the aerosol retention property of the filter paper made "by
the VDK ultramicrophotonetric method before and after aspiration showed that
the number of particulates which passed through the filter paper amounted to
only a few percent. Attempts made to precipitate the particulates which
passed through the filter paper by the electrostatic precipitation for elec-
*-*
tron microscopic study were unsuccessful because the numerical concentrations
were too low for the preparation of appropriate and reliable counts..
The retention of aerosol fogs and soluble dust can be accomplished with
**. .
the use of porous glass filters, manufactured in four grades. These were
tested for their retention capacities of lead oxide aerosol. The filter
plates were 25 nun in diameter. Aspiration rate of 15 1/min created a pres-
sure drop of 10 - 15 mm of mercury with plate Ho. 1, 80 - 85 mm with plate
No. 2. At aspiration rate of 7 1/min with plate Ho. 3 a pressure drop of 200
mm was created. The filtration system consisted of a glass filter plate fol-
lowed lay a successively connected paper filter. Aspiration was carried out
at the rate of 15 1/min. The results are presented in Table 5-
The data show that glass filter plate Ho. 1 had a low lead oxide aerosol
retention capacity; glass filter plates Nos. 2 and 3 possessed ladequate aero-
sol retention capacities. At lead oxide aerosol concentration of 0.2 mg/m
and aspiration rate of 15 1/min the amount of dispersed oxide of lead not
retained by these glass filters did not exceed 10 - 1556* Analysis of the
data presented in Table 5 shows that a connection existed between the in-
crease in the concentration of the aerosol under study and the increase in
the percentage of the particulate retained by the glass filter plate. Since
the original surface o;f the filter plate was small, it appeared that the par-
ticulate accumulation aided in the retention of further oncoming particles
by forming a dense layer over the glass plate surface in the case of higher
aerosol concentrations.
p"-
Tests were made for the retention capacities of liquid absorbers using
absorber apparatus of the Rykhter construction. We used 3£ HHO-, $% solution
of ammonium acetate and 50% aqueous solution.of glycerol as liquid absorbers.
Ifhe results are presented in Table 6. The data indicate that at aspiration
rate of 15 1/min the absorber set-up used failed to catch the particulates
under study to any worthwhile degree, regardless of the absorber solution
used*
-84-
-------
The results of the investigation showed that determination of concen-
trations of highly dispersed smoke (particles of which ranged between 0.1 -
1.5 n) could be satisfactorily accomplished by aspiration of air samples
through ash-free filter paper of the makes tested, or through glass filter
plates Kos. 2 and 3. Filter paper has the additional advantage of combusti-
bility thereby reducing to a minimum loss due to adsorptive retention "by the
filtering material. Cotton filters, glass filter plates No. 1 and liquid
absorber apparatus of the type of Gernet-Bykhter are not recommended for use
in the study of aerosols (smokes) of high dispersion.
Table 4.
Results of lead smoke retaining capacity of paper filters
Fb con en
in mg/m
0.58
0,72
5.37
6.02
16.1
0,1
0'.I25
0.42
0,55
1.2
0.76
5,1
15
20.1
0.32
0.38
1
3
12.04
O.I
0,16
3.i
11.32
— 1-1
-------
Table 5.
Filtering capacity of porous glass filters
Conc'n.
v3
0.4
0.72-
3.12
3.62
8
10.5
0,?8
0.29
2.37
9,1
12
0.22
0,26
2.3
4.56
Prtole
in co3
1.5-10*
2.5-10*
I, 2- 10s
1.5-10*
4.0-IO*
5.0-10*
M0»
1-10*
6:10*
4-10*
—
__
6-10*
3-10*
Fb retained
in Y
• Glass ,
15,3
37.5
64
87.5
300
450
25
24
112.5
450
600
*
20
25
112.5
225
Paper
20
34
90
93.7
100
125
3.3
4.8
6
4
4 .
2
1.2
2,2
3
Pb retained
Glass*
43
52,5
41,6
48,3
75
78.3
88,3
83. S
95,2
99,1
99.3
90.9
95.5
98
98.7
Paper
57
47.5
58,4
51.7
25
21.7
H.7
16.6
+.8
0,9
0,7
9.1
4.5
2
1.3
•
*^.
OH;
.
2
2
"2
2
2
3
3
3
3
«-*»»
&.
.88
100
50
50
50
50
100
100
50
50
SO
100
100
50
50
Table 6.
Rotension capacity of fluid absorbers
Description
Apprtus.
Gernet
»
>
.
s
Bykhter
Flow] To.
5
g
p.
•H
rH
\r\
60
50
50
50
50
50
Absorbing fluid
3# nitric acid
Ditto
acetate
^°* ic3u??8n*
Ditto
3£ nitric acid
mg/ffl
7.4ft
10.6.
6,6
S. 4
4.9
0.6ft
Fb'
^retained
> in Y
*i
300
400
206
£55
187
18.7
A3
.73-
128
76
64
G6
14
Fb retail
Ml
80.4
76.8
73.3
80 .
77
87.1
Mfc
19.6
24,2
;26.7
20
s*
48.9
Bibliography
JI
rpATVPA
M: C. rj^Cypr C JU XaflHSoea O- fl. Hpaimwecicoe pyxo-
•OACTBO no npOMumJitHHa-caMrirapHOi XHUUH, Jl.» 1954, crp. 24—25. — Bacn^Bit* A- H.
HfypBHuC. C. 3aB..x!fa6.. 1955. Ml. crp. 83—,4. — 111 e • T e p A. B.. P o r.ii •-
cKHfl C. 3. H Cax»>oBa c- B- H3-B- A**"- Hay* CCCP, OTA. XMM. Bayic. 1946. M 5.
crp. 491—495._BXao. Borries. Die Obermikroskopie. Berlin. 1949. —Drum-
in ond D. G. Joi^n. royal, microscop. soc. 1952. March, p, 53—55.—I ngram W. T.,
D i e r i n g e r jff. Amer. Ind. assoc. quart. 1953. v. 14, N. 2. p. 121—132, — R i c d c 1 G.
j> *~ .._ --- N 3,3. 2ffl^-232. , .„
nocryoHM SVt 1KB r.
Kollold.
-86-
-------
Sanitary-Technological Evaluation of Ash-Catching Systems Used in
U. S. S. R. Electric Heat and Power Plants.
V. F. Uzhov.
Institute for Making Gas Purifying Equipment, Technological Division.
Gigiena i Sanitariya 23, Ho. 3, 1958, pp. 15-19-
Two systems of ash-catching are presently in use in the U. S. S. K.
electric heat and power plants which are burning hard fuel: l) dry methods
with the aid of battery cyclones and electrostatic precipitators, and 2)
wet processes using centrifugal VTI scrubbers or 1SP-WI wet rod type ash-
abaters. In the past electric power plants predominently employed the dry
type of ash-catching equipment; at present the trend has been reversed and
the wet types of ash-catching installations have "been favored predominently.
The wide application of wet ash-catching installations was largely stimulated
by regulation Ho. 30 of the Council of the Ministry of Electric Heat and Pow-
er Plants of the U. S. S. B. issued 18th November, 1955j entitled "General
Announcement of Experience with Ash-Catching Installations of the Wet Princi-
ple VTI*1, which discussed the technical points of wet ash-catching apparatus
and recommended their use in electric plants on a broad scale. (Elektricheskie
Stantsii Ho. 2, 62-3f 1956). In this connection it appeared desirable to
evaluate the two ash-catching systems and to make a rational choice.
The efficiency of the MP-7PI ash-catching apparatus was studied "by the
Technological Council of the Ministry of Electric Stations of the U. S. S. R.
The results are presented in Table 1.
The data presented in Table 1 show that the efficiency of the installa-
tions reached 95# only in the Zuevsk GEES; in this connection it must be
noted that the ash particles were of large diameters and that the percentage
of the uncombusted material in the carry-off was high. In the other cases
the ash-collecting* efficiency did not exceed 90£, On the basis of the data,
9<$ must be taken as the ma-rirmim ash-catching efficiency of the wet type in-
stallations.
Data on the ash-catching efficiency of dry installations, such as elec-
trostatic filters alone or in combinations with battery cyclones were ob-
tained by the Giprogazo-otchistka Institute under operating conditions; they
are presented in Table 2.
-87-
-------
Electric
station
TABLE 1.
Type of : Combustion s Gas purifi- :
fuel used : method ; cation in % i
~ .
nemancs
CHES No. 4
fcos-energo
Lower Moscow'
coal
91/92
'
According to GEES No. 4
and Mosenerg records
only
»"£»•*. Pulverized 84.7/90
A~sh Pulverized 94 . 7/95
TABLE 2.
Large sized ash parti-
cles; 44 — 50£ incom-
pletely combusted par-
ticles in the carry-off
1
Electric station]
i
Kurakhovsk GRES
Leningrad GES-2
TEPs of Likhchev
Auto— plant
TEPs No. 11
LI os- en ergo
TEPs No. 11 - ..
Mosenergo
Shchekinsk GEES
TETs No. 12
Ti£V\c?£ii"iai*£rft
i
] Type of fuel used
i
Coal enrichment
waste products
Xnyinsk coal
Lower Moscow coal
Lower Moscow coal
Low grade coal
Lower Moscow coal
Low grade coal
: Combustion :
: method :
Pulverized
Pulverized
Pulverized
Pulverized
Pulverized
Pulverized
Pulverized
Type of : Gas purifi-
installation : cation in %
DGP
BTs+DVF
BTs+DVP
BTs+DVP
BTs+DVP " "
DVP
BTs+DVP
95.0
96-
93 -
95 -
97 -
95 -
97
98
95
96
98
97
Note: DVP - Vertical plastic smoke electrostatic precipitator; DGP - Horizon-
tal plastic smoke electrostatic precipitator; BTs+DVP - Combination ash-
catcher consisting of battery cyclone and vertical plastic smoke elec-
trostatic precipitator.
According to the data presented in Table 2 the efficiency of the above
type of dry ash-catching installations was 9556 and over, indicating that the
dry type of ash filters operated with an efficiency twice -as high as the wet
filters, since the residual ash the smoke gases discharged into the atmospher-
-se-
-------
ic air at 95£ purification was only half of that found at 90£ gas purifica-
tion,
In dealing with the problem of attaining a s&oke gas purification from
ash in compliance with prescribed sanitary-hygienic norms for inhabited lo-
calities located in the proximity of electric heat and power stations, some
simple calculations should be made of atmospheric air dust density, and the
data obtained by investigators of sanitary-hygienic institutes should be crit-
ically examined. First, let us investigate an electric plant of average (me-
dium) size, having 4 operating boilers of the TP-240 type, which consumes an
average 280 - 3OO tons of lower Moscow coal per hourj the electric plant is
equipped with ash-collectors which operate at 90£ efficiency and has a smoke-
stack 120 meters high* In 1955 a- study was made of the atmospheric air of an
inhabited region in the proximity of that electro-station. The study was made
under the direction of B. P. Gurinov by If. T. Kckarov and A. K. Yakovleva, all
of the P. P. Erisman Institute of Sanitary Hygiene of the Ministry of Health
of the R. S. F. S. R. They established that with a 90# gas purification effi-
ciency the station discharged into the air 6-7 tons of ash every hour. Cal-
culations of atmospheric air pollution at different distances from the station
were niade "by the method of P. I. Andreeva on the basis of 20 - 30 minute anal-
yses. The data obtained are presented as curve (2) in Graph 1. Curve (l) of
the same Graph represents maximal single concentrations of ash obtained by the
above named investigators in a study of the atmospheric air. The theoretical
curve of air pollution is in reasonable agreen&rit with the experimental curve.
The differences in actual, especially maximal, values can be accounted for by
differences in atmospheric conditions and local topography. (See Graph l).
The results of the study indicated that the medium sized electric power
plant generated an atmospheric air dust concentration 4-8 times as great as
the limit of allowable single maximal concentration within a radius of 4 kl,
despite the fact that it was equipped with dust-catching installations which
operated st 90J& efficiency and in the face of the fact that the smoke gases
were emitted at a height of 120 meters above the ground. This means that even
*
in the case of medium sized electric stations a smoke gas purification from
ash of 90/5 efficiency exceeded the required sanitary-hygienic norms of air
purity. In the case of the larger more powerful electro-stations which burn
coal of a higher ash content and in larger quantities and the ash-catching
-89-
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c
o
•H
•P
0)
g
o
o
-p
CO
O
r-l
-H
CO
i
-H
I
DiflTance "in meters
1 - Calculated curve of air pollution at 90^ effi-
ciency of ash-oolleoting installations (by the meth-
od of P. I. Andreova)} 2 - experimental curve of
air pollution at 90^ efficiency of ash-collecting
installations according to the data of the P. F.
Erisman Sanitary-Hygienic Institute) 3 -' curve of
air pollution at 975& efficiency of ash collecting
installations, calculated by the P. I. Andreeva
method
installations of which operate at 90£ efficiency the resulting pollution must
"be intolerably high. It appears from ths above that the required sanitary-
hygienic norms of air of inhabited localities can be met only when the ash-
collection installations of the nearby medium and large electric power sta-
tions operate at an efficiency of not less than 95%. For purposes of illus-
tration and comparison there is included in the graph curve No. 3 which pre-
sents results of maximal single concentrations of dust in the atmospheric air
(calculated by the P. I. Andreeva method) in the vicinity of the medium sized
electro-station .assuming that its ash-catching installations operated at 9756
efficiency. The curve shows that the maximal values of dust concentration in
the air under such conditions are close to the range of allowable concentra-
tions. It was previously shown that only the dry system ash-collectors, such
as the electrofliters or combined electrofliters and battery scrubbers, can
attain a smoke gas purification of such high efficiency.
-90-
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In comparing the advantages and disadvantages of the wet and. dry types
of ash-catching installations for use in electro-stations other points, in
addition to the above, have to be considered* Ash collected by the vet system
comes out in the form of mud and presents difficulties in its hauling away
because of its weight and consistency; ash aud is not suited well for commer-
cial utilization as is dry ash. A survey made of 65 new electro-stations in
the U. S. A. indicated that approximately 50£ of them were equipped with elec-
trofilters or with combined two-stage ash-collectors, or with dry scrubbers
and electrofilters combined, the regaining 50$ have dry mechanical (scrubber)
installations. Nearly one half of the electro-stations utilize the collected
ash, some using it as a filler, and 4 stations use it in the preparation of
cement.
It can be concluded from the discussion presented that the wet type of
ash-collecting eqiiipment installed in electro-stations fails to satisfy the
required sanitary-hygienic norms adopted for community air and that such
equipment is ill suited to the utilization of the collected ash for various
commercial purposes and should be regarded as wasteful from the viewpoint of
national economy.
Conclusions.
1. In order that sanitary-hygienic norms adopted for community air puri-
ty may be attained in regions where medium sized or large electro-stations are
located (such as are burning 250 tons of lower Moscow coal per hour) the lat1-
ter must be equipped with ash-collecting installations capable of purifying
smoke gases with an efficiency of not less than 952»»
2. The efficiency of wet system ash-catching equipment (UP-VTI or wet
centrifugal scrubbers VTl) did not exceed 90#. Ash collected by the wet sys-
tems presents serious hauling away problems and makes utilization of the col-
lected ash for commercial purposes difficult, if not impossible. The ash thus
collected must be disposed of at ash dumps, which in themselves become sources
of air dust pollution, "flet methods of electro-station smoke gas purification
can be used in small electro-stations, especially those located away from in-
habited localities. The installation of wet type ash-collectors may be sanc-
tioned in old electro-stations in.which for reasons of space scarcity the in-
stallation of electrofilters may present major difficulties.
3* Electro-stations of any considerable size which are surrounded by in-
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habited foci must be equipped with dry system ash-collectors, consisting of
combinations of two-stage ash-collectors: battery cyclones + vertical elec-
trofiltera of the DVP type, or of two- or tripolar horizontal electrofilters
of the DGP type capable of insuring smoke gas purification of not less than
952.
References.
Andreev, P. I. - Dispersion into the Air of Gases Discharged by Indus-
trial Plants, Moscow, 1952. Trudy conferentsii po voprosam zoloulavlivaniya,
shlako-zoloulavlivaniya i shisko-zoloispol'aovaniya, Leningrad, 1953*
Kharakteristiki novykh teplovykh elektrostantii SShA (USA). Hoskva-Lenin-
grad, 1955.
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Sanitary-Hygienic Evaluation of Industrial Hknissions by a Zinc-Lead Combine.
N. S. Pakhotina.
From the Eastern-Kazakhstan Regional Sanitary-Epidemiological Station.
Non-ferrous metallurgical plants emit into the atmosphere discharges
which contain sulfur dioxide, vapors and dust of compounds of lead, zinc,
copper, arsenic and other harmful substances. This author studied the degree
of atmospheric air pollution, of the soil and vegetation pollution by the
discharges of a lead-sine combine and the distance over which such pollution
extended. It should be mentioned at this point that according to H 101-54
the sanitary-clearance zone around lead-ainc combines must be 1000 m wide.
. The lead-zinc combine under investigation had the following departments:
a) premetallurgical production of lead from enriched ore concentratesj b)
production of zinc by the continuous and intermittent processes of pyrite
cinders leaching and the utilization of tailings, such as zinc cakes, sands,
etc.; c) production of sulfuric acid by the contact method from SO- formed
in the process of calcining the sine concentrates. The smokes and gases formed
in the roasting, smelting and refining departments of lead production entered
the dust-catching department which was equipped with bag type fabric filters;
after this purification step the aerosols and gases were discharged into the
air through a smoke stack 150 m high, the emission emanating frora the omcke
stack contained up to 0.108 g/m of dust, up to 0.61 g/m of lead and up to
0.26# of SOp, according to data supplied by the All-Union Scientific-Research
Institute of Non-Perrous Metallurgy. Atmospheric air pollution by zinc pro-
ducing plants results primarily from unorganized discharges of gases coming
from roasting or calcining ovens usually "built up to 30 m above the ground;
such gases carry with them into the atmosphere over 1056 of the S0? normally
entering the H.SO. producing department. Between 0.058 - 0.17^ of the SO
enters a smoke stack with some of the tail gases from the H_SO. producing
department; the smoke stack is 75 m higfcj the rest of the tail gases from this
department are emitted through a smoke stack 35 - 40 m high. In addition all
departments of the lead-zinc combine discharged into the atmosphere at a mod-
erately high level large quantities of technological, ventilation and some
other emissions through exhaust and air renewing ducts.
The territory surrounding the lead—zinc combine was. carefully 'studied
-93-
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and samples of the air, of the soil, and of the vegetation were collected
at specific time intervals. Samples were collected "by the sedimentation and
aspiration methods. In the sedimentation methods porcelain jars 25 cm high
and 55*39 era in diameter were exposed at heights varying "between 2 - 8 re for
15 - 20 days. Electrically operated and siphon operated "bottle type of as-
pirators were used. Determinations were aado for lead, arsenic and SO . At
designated points samples of soil were taken at 0 - 25 and 75 - 100 ma depth:
samples of plants were taken during their full development" and fruit bearing
periods. Soil samples were analyzed for pH, moisture content, K^SO., and
*• *r
total lead and arsenic: plant samples were analyzed for lead? arsenic and
H-SO.. Soil and plant samples taken 16 km away from the combine were simi-
larly analyzed for control purposes.
In this communication results are presented of the study of the atmos-
pheric air, soil and plants in a south-westerly direction from the combine.
Data obt^rned by the sedimentation method indicated that maximal pollution, of
atmospheric air with lead and arsenic occurred at distances between 500 -
1000 m from the combine. Results of soil sample analysis indicated that
greatest fall-out of lead and arsenic also occurred at distances up to 1000 m
from the combine. Results obtained with sedimentation samples collected along
other compass points indicated that the lowest quantity of lead, and of arsenic
fell out along the north-easterly direction from the combine at all times of
the study.
Leaf washings of poplars growing 500 m from the combine contained 7»5
times as much H_SO. as did washings of leaves taken from trees growing 5000 m
from the combine and 10.3 times as much as washings of leaves from trees grow-
ing in the control section. For the content of lead the results were corre-
spondingly 3.2 times and 73.8 times as much,.and for arsenic 11.8 and 16.7
times as much. The quantity of HJ30., lead and arsenic was lower in washings
of leaves taken from trees grown 500O m away, however, even at such a distance
from the combine the lead content was 22-5 and of arsenic and HpSO. 1.4 times
as high as in the control washings. Leaves of trees growing 2000 - 3000 m
from the combine showed signs of burns, the severity of which increased with
the closeness of their proximity to the combine.
Aspiration tests were made during September - October 195<> ^ *ne south-
westerly direction, when the prevailing winds were in the north-easterly di-
rection. .
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TABLE 1.
Atmospheric air content of sulfurous anhydride and arsenic in mg/m (leeward)
Distance from :
discharge source s
*
(in m)
Number of
samples
!
•
*
: Maximal
Content
• *
: Minimal :
Average
Sulfur dioxide
150 - 200
500
2 000
3 000
5 000
150 - 200
500
2 000
3 000
5 000
500
2 000
3 000
5 000
23
25
22
22
14
24
36
19
22
18
21
23
20
17
16.40
15-55
9.82
5-23
1.25
Lead
0.2413
0.2653
0.2073
0.1861
0.0098
Arsenic
0.157
0.032
0.021
0.011
0.74
0.47
0.47
0.32
0.17
0.0400
0.0294
0.0200
0.0175
0.0032
0.014
0.013
0,006
0.003
4.63
4.00
2.70
2.30
1.01
0.1212
0.1199
0.1144
0.0694
0.0068
O.O62
0.043
0.013
0.008
The results presented in Table 1 show that maximal single concentrations
of SO- exceeded the limit of allowable concentration in atmospheric air 33
times at a distance of 200 m and 2.5 times-at a distance of 5 taa from the
combine. The maximal concentration of arsenic in the atmospheric air at
2000 m from the combine exceeded the limit of allowable arsenic concentration
52.0 - 10.6 times (0.003 aig/in ), and at a distance of 5000 m from the combine
the maximal atmospheric arsenic concentration still exceeded the limit of
allowable concentration 3.6 times. Thus, the results of the determinations
indicate that the emissions coming from the lead-zinc combine heavily pollut-
ed, the atmospheric air with lead, arsenic and sulfur dioxide. It has been
known for some time that ingredients of industrial discharges underwent con-
siderable changes upon coming in contact with the soil as a result of which
they became potent secondary atmospheric air pollutants; they were known to
have been washed into the deeper soil layers, penetrating into and polluting
subterranean waters. Vegetation growing in such air polluting territories
-95-
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suffered the double effects of atmospheric air and soil industrial pollution.
Under industrial air and soil pollution under discussion soil fertility
may be seriously affected. Thus, SO* .and sulfur dioxide permeating into the
soil become converted into aulfurous acid which has a destructive effect on
the absorbing properties of the soilj they also render the calcium salts
soluble, so that they easily leach out of the cultivable soil layers. Ac-
cording to K. P. Karasinskii this causes coil dust disintegration. Arsenic
and lead easily accumulate in the soil and under favorable conditions of
moisture and pH become transformed into soluble compounds which plants as-
similate in quantities large enough to be harmful to the animal organism.
A study of the soil in the smoke affected region showed an extremely heavy
pollution of its upper layers with lead-and somewhat less with arsenic and
HpSO., as can be seen from the data presented in Table 2. At"distances be-
tween 500 to 1000 m from the combine the vegetation suffered some damage dur-
ing peak pollution caused by high concentrations of S0? in the atmosphere.
Conclusions.
1. Industrial discharges of the lead-zinc combine heavily polluted the
atmospheric air with 30^, lead and arsenic at all distances from the combine
at which samples were taken.
2. The degree of soil and plant pollution with lead and arsenic over
the three years of the combine's operation considerably exceeded the content
of lead and arsenic in the soil and on plants of the control region.
3. Under such pollution conditions the prescribed sanitary clearance
zone of 1000 m proved inadequate as a .sanitary protection measure.
4. Steps should be taken for the elimination of all unorganized techno-
logical and ventilation emissions of the combine and for the installation of
more effective sanitary gas purifyers.
Literature cited.
Gol'dberg, M. S. - The Sanitary Protection of Atmospheric Air, Moscow,
1948, Krasinskii, N. P. - Planting Smoke Resistant Trees around Industrial
Manufacturing Plants, Moscow, 1937* Morozsov, V. A. and Komm, D. G. - (Jigiena
i Sanitariya, 1953, Ho. 6, 8-11. Byazanov, V. A. - Sanitary Protection of
Atmospheric Air, Moscow, 1954. Toms on, N. M., in book - Limits of Allowable
Concentrations of Atmospheric Pollutants, Moscow, 1952, First issue 80-89.
Khachaturyan, M. KT. - Gigiena i Sanitariya, 1955* Bo. 1, 12-a6.
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TABLE 2.
Content in soil - fcrestlike argillaceous - of sulfuric acid, lead
per 100 grams of air-dried soil.
Distance
from pollu-
tion source
in m.
500
1 000
2 000
3 000
5 000
16 000
(control)
Sulfuric acid
t Surface- i
t layer t
476.43
621,42
309.31
229.92
149.63
59.78
0.25 om |
148.11 :
.104.13
73.42
'54.25
52,94
22,86
75 - 100 i
cm i
10.76
•
; 7.42
. 6.05
: 4.50
; 4.24
Surface
layer
23.9711
9-0163
1.4207
1.2192
0.1031
0.0943
Lead
j 0.25 om |
4.1747
1,8368
0.7432
0,5991
0.0649
0.0778
i
:
75 - 100 i
cm *
0.0748
—
0.0545
0.0474
0.0233
0.0292
and arsenio in ing
Surface
layer
3.702
2.783
2.719
1.721
1.425
0.450
Arsenio
| 0.25 cm |
1.882
1.663
0,950
0.734
0.263
0.305
75 - 100
om
0.196
-
0.064
0.017
0.012
0.007
-------
Establishing Marl gnim Allowable Concentration of Hydrogen
Sulfide in Atmospheric Air,,
I. F. Glebe va.
(From the Institute of General and Community Hygiene of the Academy
of Medical Sciences of the U. S. S. K. )
Gigiena i Sanitariya, No. 4, 1950, pp. 19-21.
The hygienic effect of low concentrations of industrial gases in atmospher-
ic air can be determined in some cases by objective evaluation of the reactions
of the human organism to such gases* In this connection data are hare presented
obtained in the study of atmospheric air pollution by a viscose-rayon factory.
The study was not extensive but the results merit the attention of hygienists.
It was previously demonstrated, (Gigiena i Sanitariya, Ho, 6, 1949, PP* 27-34)
that the artificial silk plants* atmospheric air pollution with hydrogen eul-
fide and carbon disulfide extended up to 2 km from the source of pollution, the
highest pollution was noted within a radius of 1 km where the maximum single
concentration of hydrogen sulfide was 0,05 mg/m and of carbon disulfide -
0,075
To determine the effect which hydrogen sulfide and carbon disulfide may
have on the human organism observations were conducted in nurseries on children
1 month to 3 years old. One factory nursery was situated 800 m northwest of
the factory, the other nursery was located 2 km south of the plant in an area
of relatively Ion and infrequent pollution. At the end of 1947 and the begin-
ning of 1948 the nursery physician, P. G. Vinogradova, noted that some of the
90 breast-fed babies were poorly developed and did not gain weight, and that
their weight was highly variable. The babies reacted listlessly to their sur-
roundings, occasionally they were lifeless, anemic and pale. The stools were
dyspeptic. The babies regurgitated immediately or 30 to 40 minutes after
breast feeding. They were susceptible to infectious diseases which took on a
more severe form than usual. These babies were retarded in their physical, de-
velopment; they began to walk late and their teeth were late in cutting
through.
A careful investigation revealed the cause of these phenomena; the mothers
of these babies worked in the spinning shop of the artificial sil& plant. Coot-
ing into the nursery at certain hours to breast feed their infants the women
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washed their hands and started to nurse their babies without talcing off the
work clothes. An unpleasant heavy odor of the "spinning shop11 emanated from
their clothes, particularly in rainy, weather when the clothes were damp. The
babies nursed well, but immediately after feeding, or a short time later, they
regurgitated; over-feeding was ruled out as the cause. Slipping on a robe over
the work clothes did not produce the hoped for prophylactic results. Regurgi-
tation and dyspeptic stools persisted. This lead the physician to suspect that
there was a connection between the infants inadequate development and sickness
and the mothers occupation. She insisted that nursing women who worked in the
spinning shops should be assigned some other workshop or to some auxilliary
work for the period of breast feeding. This simple measure yielded favorable
results. The babies stopped regurgitating, their stools gradually improved and
they began to gain weight although, in the beginning, they lagged in development.
Excerptb from two histories of infants' development are presented:
1. D-n Vova, weighed at birth 3,100 g. Housing and living conditions sat-
isfactory. Mother worked full time in the spinning shop. The baby boy was ad-
mitted to the nursery at the age of 1-1/2 months on May 8, 194?. Child was
undernourished at the time of observation, the skin and mucous membranes were
pale, the skin was flabby. Before admission to and while in the nursery the
baby's physical and neuro-physical development were slow. After breast-feeding
he regurgitated; stool was dyspeptic; he slept well. The baby did not sit up
at 10 months, began to walk at 1 year 5 months, weighed 6,950 g instead of
10 kg and his development corresponded to that of a 7 month old baby. When the
mother was moved to another workshop, where concentrations of free hydrogen sul-
fide and of carbon disulfide were low, the baby*a development improved.
2, Ava Galya, weighed at birth 2,700 g. Housing and living conditions
satisfactory. Mother worked full time in the spinning shop. The baby girl was
admitted to the nursery at the age of 2-1/2 months on April 2, 1947. At the
time of observation the baby was undernourished} the outer mucous membranes
were of normal color; weight was variable; appetite poor; stools dyspeptic and
frequent; frequent regurgitation after nursing; sleep was normal; development
retarded. At the age of 14 months her development and weight corresponded to
those of an 8 month old baby; the weight was 7»220 g instead of 9,500 g; began
to walk at 17 months. First teeth appeared at 14 months. The baby had influ-
enza, bronchitis, measles, chicken pox and dyspepsia. After the mother was
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moved to another workshop, the "baby's development improved and her weight came
to near normal,
An analogous oase occurred in the other nursery situated 2 km from the
plant. The physician noticed peculiar symptoms in a breast-fed babyj vomiting,
dyspeptic stools, and a retarded general development. The symptoms were those
of an ordinary simple dyspepsia. The baby's mother worked in the spinning shop
of the viscose-rayon factory. This was the only case of its kind in the nurs-
ery and the physician failed to detect any connection between the baby's con-
dition and the mother's occupation.
The described symptoms in the children could he caused by the hydrogen
sulfide and carbon disulfide with which the mothers* work clothes were perme-
ated. To verify this, chemical analyses were made of the air collected under
the mothers' work clothes. During nursing, when the clothes were unbuttoned,
absorbers were placed between the outer garments and under clothing close to
the baby's nares so that the air which passed through the absorbers was identi-
cal with the air inhaled by the baby. Observations of mothers working in
spinning departments were conducted parallel with observations of mothers work-
ing in other shops. Analysis of the air collected as above described in the
case of mothers working in spinning shops revealed the presence of hydrogen sul-
fide in a concentration of 0.028 - 0.055 mg/m ; no detectable carbon disulfide
was reported. Ho hydrogen sulfide and no carbon disulfide were found in any of
the air samples tested from mothers coming .«o nurse from other workshops. Hy-
drogen sulfide concentrations were near the maximum allowable concentration
presently in force.
Results of this study showed that the unfavorable symptoms developed in
the breast-fed babies were caused by H?S, There appeared no basis for chronic
poisoning, but the evidence obtained indicated the urgent need of a further
study of the effects observed.by hygienicts and by clinicians. According to
the data presented by Pravdin, Pavlenko, Strakbilovich, Bainet and others, daily
prolonged inhalation of slight amounts of hydrogen sulfide (0.1 - 10 ng/n )
produced a definite symptom complex manifested as undernouriefcaent, delayed
growth, general weakness, retarded development, digestive disturbances, tendency
to vomiting and diarrhea, conjunctivitis, oatarxfe °^ tne upper respiratory tract,
bronchitis and fUroncalosis. This was laoeompaaied ty increased susceptibility
to infectious diseases; imi;aao-rd8laf€«ae*~ decreased and a peculiar eensitisation
-100*
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to certain toxins developed.
A child's organise is highly sensitive to environmental effects, particu-
larly in the early stages of its life, when the normal growth and development
are determined by specific characteristics of the physiological processes,
which can retain their normal aspects only in favorable environmental condi-
tions, A disturbance in these conditions affects the normal course of growth
and development. The effects of hydrogen sulfide in the concentrations found
were sufficiently strong to affect deleteriously the development and growth
of the child's organism. The fact should be. taken into account that hydrogen
sulfide belongs' to a group of toxins capable .of accumulating in the -organism*
as was shown by Hekhoroshev, Savinekii, Strakhilovioh and others*
The results of observations helped to determine the etiology of distur-
bances noted in the children and to remove the causes of the developing thresh-
old pathological conditions. It is suggested that the maximum allowable con-
centration of hydrogen sulfide in the atmospheric air presently in force be re-
vised since, as it appears, infants health is adversely affected by concentra-
tions lower than the health of adults.
Summary*
1. Observations conducted in the nurseries of the viscose-rayon factories
showed that a peculiar complex symptom frequently appeared in breast—fed
infants whose mothers worked in.the spinning shop.
2. Examination of the air under the upper garments of the mothers (at the
point of infant breast feeding) revealed the presence of hydrogen sulfide in
small concentration; no carbon disulfide was detected*
3. The disappearance of the clinical symptoms after mothers were moved to
different type of work established the fact that such symptoms were caused by
the hydrogen sulfide present in the air inhaled by the breast-fed infants.
4* Assigning such mothers to shops other than the spinning checked the
pathological symptoms in the babies; this should be adopted as a standard.pro-
phylactic measure. " "
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Determination of Sulfur Dioxide Odor Threshold Concentration.
I* H. Popov, Te. F. Cherkasov and 0. L. Trakhtman.
From the Chair of General Hygiene of the First Moscow Order of .
Lenin Medical Institute.
Gigiena i Sanitariya, No. 5, 16-20, 1952.
The atmospheric air is being polluted frequently by emissions coming from
manufacturing and production plants, from heat and power stations, and the like.
This is particularly true of plants which use sulfur-rich coal for gas produc-
tion, ore roasting, and other chemical processes which pollute the atmospheric
air with sulfur dioxide.
The Ail-Union Sanitary Control Office appointed a special Coa^aittee of rep-
resentatives from hygienic institutes to determine maximum allowable concentra-
tions of pollutants present in the atmospheric air. The Committee prepared two
•>
concentration standards for sulfur dioxide: a maTlrcnirn single dose of 0.75 fflg/m
3
and an average daily concentration of 0.25 mg/ia • Tn« authors of this report
undertook to find the threshold concentration of olfactory sensitivity to sul-
fur dioxide in atmospheric air, to determine its relation to the recommended
standard maximum concentration of sulfur dioxide in the air, and to ascertain
whether the odor receptor apparatus could be used in the control of concentra-
tions of noxious odor-emanating gases in the air. It has been accepted gener-
ally that the threshold of perception was determined by the lowest magnitude of
a stimulator which manifested awareness. This is known as the "absolute thresh-
old" as distinguished from the "differential threshold" which indicates how a
stimulator should be changed in order that the awareness may rise to a barely
perceptible higher level. (L. A. Andreyev "The Physiology of Sensory Organs**
M., Moscow State University, 1941). Absence of awareness of the presence of a
stimulating or irritating agent can not and should not be taken to mean that
the stimulating or irritating agent had no effect on the organisa. On the oth-
er hand9 positive perception of a stimulation or irritation is a direct
indication of their effect on the organism. For this reason, in many in-
stances air pollutant concentrations below the toxic level can be detected by
odor and, thereby* serve as safe and reliable guards against danger. In thie
report odor perception intensity was graded as followst no odor perception -
-102-
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0; slight odor perception - If notable odor - 2; strong odor - 3.
There exist two methods for the determination of en absolute threshold of
odor perception - the static method and the dynamic method* In the static
method a definite concentration of an investigated gas is experimentally cre-
ated in an inclosed constant volume of air, from which samples are taken for
odor perception tests* In the dynamic method a constant concentration of an
investigated gas is maintained in an air current* The static method for the
determination of threshold of odor perception has the following drawbacks!
the gas concentration continually decreases owing to a continuous sorption of
the gas by the container walls) fresh air seeps in during the inhalation of the
tested air mixture; it is tima-consuming. The dynamic method is free of such
drawbacks*
Some authors recommend the use of "olive-shaped" nasal plugs* Control
tests indicated that this introduced additional irritation and affected the
natural process of odor perception* A study of the physiology of sensory or-
gans showed that inhaled air did not reach the olfactory cleft directly, hat
that the odor penetrated into it in a diffused state. This makes the attempts
of some authors to deliver the tested air directly to the olfactory region with
the aid of "olive-plugs1* physiologically unsound; no use was made of such a
procedure in this study*
In the static method for the determination of threshold concentration of
odor perception, these authors used a bottle of 66*5 li in which were created
different concentrations of the tested gas* The gas-air mixture was thoroughly
homogenized and nasal inhalation tests were made'for the determination of the
presence of any odor. The gas dosage delivered into the inhalation chamber is
a factor of great importance. Exact dosage of the sulfur dioxide was adminis-
tered with the aid of a special burette supported by a universal holder stand*
The burette had a 3-say stopcock at one end and a mercury tube at the other end*
Sulfur dioxide was generated in a flask by mixing sodium thiosulfate with strong
sulfuric acid* Sulfur dioxide concentrations in the burette ranged from 1*3 -
2*3 ing/ml. The 66*5 li flask made possible to obtain accurately gas of the .
required low concentration.
The dynamic method for the determination of threshold odor perception con-
centrations of gas is a useful one. It makes possible the chemical determina-
tion of the gas concentration existing at the time of the test. Ho leakage of
-103-
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the outside air or decrease of concentration can occur with this method. It
saves tise, makes possible the change of gau concentrations so that different
concentrations can be tested under identical conditions; concentrations of the
gas can be changed gradually from gas concentrations, imperceptible to the
sense of smell, to concent rations clearly perceptible by odor, making possible
the accurate determination of absolute thresholds of odor perception.
An apparatus for the determination of absolute odor threshold of sulfur
dioxide used in the dynamic method is shown in the following drawing. A fixed
concentration of sulfur dioxide is supplied at tha opening of the glass tube)
it enters the tube and mixes with a current of aix* At point B the odor and
concentration of sulfur dioxide are determined. The apparatus is so constructed
that changes in gas concentration and rate of air current can be made at any
moment desired. With this apparatus it was possible to investigate the thresh*
old of odor perception changing from pure air to SOy-air mixtures of different
concentrations and vice versa. Determinations of low concentrations of sulfur
dioxide were cade by the rapid method of V* A. Khrustaleva and 1C. V. Takovenko
6 \»
Set-up for the determination of gas concentra-
tion in a current of air (Dynamic method)
- Glass tube} 2 - motor and ventilator (fan) supply-
ing air into tube* 3 - flowmeter; 4 - adcromonaa*t*r|
5 - gasholding burette! 6 -» mercury containing level
adjuster! 7 - ga» supply regulator; 8 - air samplia*
point| 9 - gas absorbers! 10 - aspiratorf
11 - point of odor perception tooting.
-104-
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(A. S. Shltkova, Rapid Methods for the Determining Noxious Gases and Vapors
in the Air. U.-L., Goakhimizdat, 1946). The method is based on the discolor-
ation of a known starch-iodine solution by sulfur dioxide. By slowly bubbling
the air through the starch-iodine solution and recording the volume of air
consumed in the iodine discoloration the concentration of SO. in the air can
he determined with ease and reliability.
Desired dosage of pure SO. is attained as follows i Place 30 - 50 g of
sodium thiosulfate in a Wurtz flask; add sulfuric acid one drop at a time from
a dropping burette or funnel. A while later replace the Wurts flask air with
SO-. 'Connect the side-tube of the Wurts flask with a graduated burette previ-
ously filled with metallic mercury. Place 2 ml of sulfuric acid into the Wurta
flask end open the burette stopcock; the pressure of the sulfur dioxide will
slightly lower the mercury level* Gradually lower the mercury-filled bottle
and fill the burette with the S02 mixture and determine the gas concentration*
Place 30 ml of 0*002 H iodine solution into a 100 ml bottle and add exactly 1
cm of the gas; shake for 5-7 minutes; titrate with 0.002 H hyposulfite so-
lution to determine excess of iodine.
It was demonstrated that the concentration of sulfur dioxide contained in
the burette over the mercury decreased in one day 19 - 20£, and in two days by
35 - 60£> under the same temperature and humidity conditions. These tests were
repeated in a glass bottle of 66.5 li capacity and changes in sulfur dioxide
concentrations observed at 15 - 30 minute intervals* Results showed that in
15 - 30 minutes under constant temperature (18 ) and humidity (60 - 65$) the
concentration of sulfur dioxide decreased 35 - &#. This must be taken into
account in making the threshold tests. The determination of threshold concen-
trations of sulfur dioxide odor perception was made by the dynamic method.
An analysis of the data obtained showed that a concentration of sulfur
dioxide up to 0.004 &&/li (4 cag/m ) could not be detoctod by odor. Concentra-
tions of sulfur dioxide within the limits of 0.004 - 0.0065 mg/li were per-
ceived by the majority of test subjects as having a btrong odor and by only a
few as having a faint odor* Concentrations of sulfur dioxide above 0.0085
mg/li were determined as having a very sharp odor. Data available in litera-
ture on determining the threshold of odor perception of sulfur dioxide presont
a somewhat different picture. Henderson and Huggard state that sulfur dioxide
concentrations of 0.008 mg/li to 0.013 fflg/li were almost imperceptible by odor.
-105-
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B. V. Alekseyevakii regards 0,0075 m^/ll as a minimum concentration of sulfur.
dioxide detected by odor and H. V* Laaarev reported it as 0*006 mg/li. Re-
sults here reported show the threshold concentration to be at the level of
0.004 ma/li.
Soviet bygienists regard freedom from odor as a basic requisite. The
present sanitary regulations prescribe 0*25 og/m as the mnTlimim daily average
SO. concentration and 0*75 nig/m as the maximal single SO. concentration in
atmospheric air* Results of this investigation show such concentrations to be
above the threshold of SO. odor perception. It is suggested that they be re-
placed by results of more recent and more sensitive studies*
The Stimulability of the Olfactory Analyzer in the Hygienic Evaluation
of Atmospheric Air -Pollution.
A* A. Itskovich*
Cigiena i Sanitariya, Ho. 8, $-11,
In the study of effects of city atmospheric air pollution pertinent in-
formation can be obtained from an investigation based on the olfactory analyzer
function of those inhabiting vicinities under observation. I. P. Pavlov shoved
that stimulation applied to a given receptor apparatus affected the functioning
of other organs. Results of recent physiological investigations shoved that
such secondary effects of the olfactory organs extended over a vide scope of
the organism's functions, such as the emotions* work efficiency* general me-
tabolism* the cardiovascular function, muscle stizaalability* the electric skin
potentials, etc. This author studied the functional shifts in the human organ-
ism which resulted from atmospheric air pollution by volatile products of the
coke-chemical industry, such as tar. phenols, benzene, etc. j . the effect of
these substances on the state of the olfactory analyser in various population
groups was used as the selective index of pollution effects*
-106-
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The Elsberg-Levy apparatus as modified by the Institute of Labor Hygiene
and Occupational Diseases of the AM3 (Acad. of Med. Sci.) of the U.S.S.R. was
used in this investigation* The state of olfactory sensitivity vas determined
by the "olfactory coefficient", that is, the volume of air in ml which the in-
ventore designated for the apparatus. .It has been established that the "ol-
factory coefficient^ or threshold for each substance studied, was constant
and well defined for normal individuals; this fact makes possible the deter-
mination of normal "olfactory coefficients", or thresholds which can be used
as standards of comparison in experimental studies.
In the selective group-studies crystalline phenol and thymol were used as
the odor-emanating substances, and the threshold of odor perception was estab-
lished when no odor was sensed at the stage of intermittent inhalation* Tests
were made on 241 individuals divided into 4 groups. Group 1 consisted of work-
ers and technical personnel of a coke—chemical plant, i.e., persons exposed to
the direct effects of phenol under actual production conditions; group 2 con-
sisted of residents within 300 - 1000 m from the production plant; group 3 con-
sisted of school children living in the same area; group 4 consisted of employ-
ees of the Sanitary Institute who had no direct connection with the source of
the atmospheric air pollution. Ages of the adult group ranged between 18 - 39
years; ages of the school children ranged between 12 * 16 years. 70$ of the
individuals of group 1 had a work record of 4 years or longer; the inhabitants
of the city section under study were old time residents.
All test subjects were examined medically. "So noteworthy anatomical or
physiological abnormalities of the olfactory organs were found in any of the .
persons under investigation. The upper respiratory tracts were in a normal
state, with the exception of a few individuals who had cataxrhal symptoms. It
was concluded that deviations observed during the preliminary medical examina-
tions were negligible and could in no way affect the results of the olfactory
threshold investigations* The majority of the individuals manifested a normal
level of perceptibility to the smell of food; the food odor threshold perception
of 20£ of the plant workers was somewhat below the normal level. Isolated cases
of lowered threshold of food odor perceptibility were observed also among the
other groups. In reply to questions such Individuals expressed the belief that
the cause of their lowered threshold of food odor perceptibility was due to
their prolonged residence in vicinities of polluted atmospheric air.
-107-
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All persona under investigation were questioned regarding their sensitivity
to odors characteristic to coke-chemical industry. The replies indicated that
in 77? of group 1 the threshold of such odor sensitivity was lowered} being
away from the exposure conditions as during periods of vacation or other ab-
sences restored the original degree of sensitivity to the coke-chemical odors.
Some workers stated that upon returning to the original occupational conditions
they experienced symptoms of weakness and subjective sick feeling accompanied
by headaches, lack of coordination, loss of appetite, etc. which lasted only a
few days.
Members of group 2 also registered complaints related to loss in the acuity
of odor sensitivity to the specific coke—chemical odors. Some of the individ-
uals of group 2 stated that being away from the locale investigated and remain-
ing in an air-pure atmosphere for only a few hours brought back their normal
perception of the coke-chemical odors*
The question and answer investigation was followed "by an olfactometric
study of the odor perception threshold in the.same four groups. Results of
previous studies established that the threshold of phenol and thymol odor per-
ceptibility in persons with normally functioning olfactory organs rested with-
in the limits of 3 - 10 ml* Accordingly, thresholds of odor perceptibility to
the specific substances under investigation must be regarded as not normal and
presumed to be the result of occupational disturbances caused to the olfactory
analyser by exposure to the effect of such substances during work. Such ol-
factory analyzer and functional disturbances were observed among workers directly
in contact with coke-chemical processes as well as among residents of nearby
vicinities.
The olfactory analyser disturbances were not as profound in the school
youngsters, and only an occasional individual of the control group (members of
the Sanitary Institute personnel) showed symptoms of functional olfactory dis-
turbances, as can be seen from the following Table,
Conclusions.
1. Determinations made with the aid of the Blsberg-Levy olfactometer
shoved that in 66.6% of workers under study and of persons residing 500 - 1000
m from the coke-chemical plant the threshold of coke-chemical odor perception
was above the normal. The same was true of 50$ of the youngsters of school
-108-
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Phenol t Thymol
. .
_-, _______ _. . . ob- } normal Lw^^i^ I Ho*nal Lv ^u
3-10
Workers and technical
personnel 82 13 24 45 12 30 40
Residents of the near-by
miororegion and employee*
of the near-hy B-H station 70 12 22 56 11 23 36
School youngsters 58 24 22 12 23 18 1?
Sanitary Institute personnel 30 24 42 24 5 1
2* The results of olfactory threshold datarainations were in complete
agreement with the anamnestic data secured from the same population groups.
3* The changes observed in the olfactory sensitivity of the groups were
of a specific character and could be regarded as effects of the coke-chemical
atmospheric air pollutants.
4* It was noted that persons with pronounced changes in the olfactory
sensitivity resided within 300 - 1000 m from the source of atmospheric air
pollution where, according to analysis, the concentrations of phenol compounds
in the air ranged between 0.16? - 0.237 og/ra * This should be taken into con-
sideration in the determination of the limit of allowable concentration of
phenol in atmospheric air,
The results here presented point to the inadequacy of the sanitary clear-
ance zone prescribed in H 101-34 in connection with coke-chemical production
plants*
-109-
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Experimental Determination of the Limit of Allowable Concentration
of Dichlorethane .in. Atmospheric Air*
U. K. Borieova.
(The P. P. Erisman Moscow Scientific-Research Institute of the RSFSR
Ministry of Health).
Gigiena i Sanitariya 22, Ho. 3, 13-19, 1957-
Industrial enterprises which produce or use chlorinated hydrocarbons in
connection with their manufacturing processes constitute sources of air pol-
lution with vapors of chlorinated hydrocarbons. U.S.S.R. and foreign literature
shed little light on this subject despite the fact that chlorine substituted
compounds possess properties which assure their increasing use in any national
econoxqy.
Dichlorethane, as the ethane group solvent of chlorinated hydrocarbons of
the fatty order, possesses high solvent power, high volatility, low inflamma-
bility and a low explosive index; because of its low cost it is used ever more
extensively in industries for the extraction of fats, oils, tars, resins, wax,
paraffin, etc.) it is also used as an antiseptic and fungicide. It is suprising,
therefore, that no limit of allowable concentration of dichlorethane in the at-
mospheric air was set by the Committee on Limits. To fill this gap this author
undertook to make a study of this subject. As the first step some data were ob-
tained regarding the intensity and other characteristics of dichlorethane air
pollution by industrial production and manufacturing plants; parallel with this
some experimental data were secured regarding the effect of low dichlorethane
concentrations on man.
The studies were centered around two industrial plants which had been pol-
luting the air with dichlorethane vapor. One plant discharged into the atmospher-
ic air dichlorethane vapor coming from the manufacture of synthomycine. This
discharge amounted approximately to 1100 kg of the dichlorethane vapor at every
stage of synthomycine production. The other plant discharged daily approximately
1300 kg of dichlorethane into the atmospheric air in the manufacture of high quali-
ty lubricating oils and greases. Samples of atmospheric air were collected at dif-
ferent distances on the lee side of the plant into $00 - 600 ml gas collecting pi-
pettes, originally filled with a solution of BagSO-. Studies were made in the sum-
=3r, when the outdoor air temperature was 25 - 30 . Chi ore thane determinations
-110-
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were made by tho microcombustion method in a gas analyzer constructed for the
purpose "by D. P. Senderikhina of the P. P. Eriaman Institute, in 1954. The .
products of combustion were aspirated through an absorption solution *"*fl the
Cl ion determined nephelometrically. The sensitivity of the method waa 0.001
mg per determination. The results obtained for each of the plants are pre-
sented in Tables 1 and 2.
TABLE 1.
Maximal single concentrations of dichlorethane vapor in the atmospheric air
in the vicinity of the plant producing synthetic synthomycine.
Distance from i
source of i
pollution :
in m, :
100
250
500
1 000
i 500
:
Number of :
air samples i
*
*
40
44
45
45
45
TABLE 2.
Concent rat ions
Average
12.2
8.7
8.4
5.5
3.7
in mg/m
Maximal
33.1
20.9
33.0
21.9
28.5
Maximal single concentrations of dichlorethane vapor in the atmospheric air
in the vicinity of the plant producing high quality lubricating materials.
Distance from
source of
pollution
in m.
100
250
500
1 000
i 500
2 000
: :
: Number of t
: air samples :
s :
57
58
60
58
65
59
Concentrations
Average
19-4
18.3
8.8
8.2
3.9
3.5
in mg/m
Maximal
38.6
35.3
25.0
20.0
22.4
17.6
Data in Table 1 indicate that 21 of 219 air samples contained dichloreth-
ane in percentages below the limit of the method's sensitivity. Such samples
were taken at distances of 1000 - 1500 meters from the plant. Table 2 shows
that 53 of 357 air samples likewise contained dichlorethane in concentrations
below the sensitivity of the methodj the data recorded in this Table also
show that single concentrations of dichlorethane were only 50 - 65# of the
limit of concentrations of dichlorethane permissible for the air of work
-111-
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rooms and shops. Thus, the results of the preliminary study pointed to a
high degree of dichlorethane air pollution by either of the plants investi-
gated.
The effect of low concentrations of dichlorethane on man was studied by
the method of threshold of odor perception of dichlorethane by the adapto-
meter method and "by the methods of plethysmography and spirography. A spe-
cial set-up was designed which enabled the delivery of any desired concentra-
tions of the dichlorethane and which assured the constancy of any desired di-
chlorethane concentration for as long as the test period required. Twenty-
one persons aged 16 - 55 years were thus studied under controlled laboratory
conditions which assured precision of testing and accuracy of results. (See
Table 3). The total of tests made was 1256.
TABLE 3*
Dichlorethane concentrations in mg/m and the degree of its odor perception.
Initials
of test
individual
A. G.
A. H.
A, T.
B. M.
B. - B.
E. B.
I. T.
I. L.
K. M.
K. K.
K. B.
K. G.
L. P.
L. A.
B. H.
U. T. -
S. 0.
Kh. E.
F-na.
Sb-ch.
t Dichlorethane r
i odor not :
t perceived t
0-12
0-23
0-23
0 - 17*1
0-23
0-23
0-23
0-23
0-23
0 - 17.1
0 - 17.1
0 - 17.1
0 - 17.1
0 - 17.1
0-23
0 - 17.1
0-23
0-23
0-23
0-23
Dichlorethane
Moderately
12.2 - 24.6
23.2 - 24.6
23,2 - 24.6
17.5 - 23.0
23.0 - 24.6
23.2 - 24.6
23.2 - 24.6
23.2 - 24.6
23.2 - 24.6
17-5 - 26.7
23.2 - 26»7
17.5 - 23,0
17.5 - 23.0
17-5 - 23.0
23.2 - 30.0
17-5 - 24.6
23.2 - 24.6
24.9 - 26.7
23.2 - 24.6
— —
odor perceived
s Clearly
24.9 - 26.7
24.9 - 26.7
24.9 - 26.7
23.2 - 24.6
24.9 - 26.7
24.9 - 26.7
24,0 - 26.7
24.9 - 26.7
24.9 - 26.7
29.0 - 30.0
29.0 - 30.0
23.2 - 24.6
23.2 - 24.6
23.2 - 24.6
30.2 - 32.3
24.9 - 26.7
24,9 - 26.7
29.0 - 30.0
24.9 - 26.7
23.2 - 24.6
The results listed, show that 12 test subjects sensed the odor of di-
chlorethane in 23.2 mg/m concentration, 6 in 17*5 ni£/m concentration and
one each in 12*2 and 24.9 tog/a concentrations. If the results of threshold
-112-
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of odor perception tests of the majority of the test subjects are taken as
the basis of our determination, then 23.2 mg/m of dichlorethane should be
regarded as the concentration of dichlorethane threshold of odor perception,
despite the fact that persons with more sensitive olfactory mechanism sensed
the dichlorethane odor in 17.5 and 12.2 mg/m concentrations.
In using the method of eye sensitivity to light we employed the AJS!
adaptomoter. Three test subjects were selected aged 17 to 24 years. The
threshold of dichlorethane odor sensitivity of these individuals was 23*2
mg/m for two (K and B) and 25 mg/m for one (T). The first 5 - 6 days sere
used for preliminary training; following this, tests were made to establish
the specific normal reaction-thresholds of each test subject (adaptation to
darkness). This in turn was followed by actual experimental tests during
which the persons were administered, with the aid of special apparatus, mix-
tures of pure air and dichlorethane in known concentrations, starting with
lowest concentrations. Inhalation of the dichlorethane vapor was continued
for 15 min. prior to testing changes in dark adaptation. Tests were made with
dichlorethane concentrations ranging from 4 to 50 mg/m , a range which repre-
sented subthreshold, threshold and above-threshold dichlorethane concentra-
tions, as judged by odor perception.
The results showed that the inhalation of vapors of dichlorethane re-
sulted in recordable changes in eye sensitivity to light as compared with the
normal. The changes are graphically plotted in Figures 1 and 2* Fig. 1 is
the record of changes in eye sensitivity to light of test subject K and of
the process of one hour's dark adapatation during the inhalation of different
concentrations of dichlorethane. The data plotted in Fig. 1 show that at
dichlorethane concentrations of 6t 17> 23 and 50 mg/m the sensitivity to
light increased with the. increase in the concentration of the dichlorethans
vapor. Fig. 2 shows a fall or a rise in the intensity of sensitivity to
light on the 40th minute in the case of all test individuals, as indicated by
the appropriate blocks: in the case of K and B a concentration of dichloreth-
ane of .9. mg/m lowered their sensitivity to light and in the case of T the
sensitivity to light rose. Concentrations of 12 mg/m lowered sensitivity to
light in the case of K and B and had no effect in the case of T. The inhala-
tion of dichlorethane concentrations of 1?.5» 23.2, 25.0, 30,0 and 50.0 mg/m
brought about a lowering in sensitivity to light in all three test individ-
-113-
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SO 5$ 68
ss of stay la dark rooa
Fig. 1. Ifre senaitivity to light after dichlorethane
halation ty test subject K 15 ain. before adaptation
4» O
tS
S tZ iT.5 V.* *$
Concentration ln'ag/'«
QJ
Fig. 2. Decrease or increase in eye sensitivity to
on the 40th «inute of adaptation at different di-
ohlorethane concentrations*
1 - individual Kj 2 - individual B| 3 - individual *.
-114-
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uale; at 30.0 mg/m the lowering of eye sensitivity to light was most marked.
On the basis of that it can be stated that concentrations of dichlorethane
imperceptible to the olfactory organs can have a measurable effect on eye
sensitivity to light.
The results of our observations are in complete agreement with the data
presented by B. M. Galochkina, G. V. Gershuni, P. I» Dubrovskii and others
who shoved that the sensitivity of the eyes to light can be affected by other-
wise non-perceptible stimuli. Hence, the non-perception of odors by the ol-
factory route can not be taken as proof that a given substance may exert no
effect on the cerebral cortex.
The effect of low concentrations of dichlorethane on vascular reaction
was studied by the method of plethysmography. Vascular reactions, as com-
pared with other reactions of the organism, are characterized by a high, de-
gree of mobility and responsiveness, and can serve as very sensitive indica-
tors of the state of.cortical processes of man. The method of plethysmogra-
phy enables one to study pulse variations and changes in the blood volume in
man's extremities (appendages).
We used the triple-duct finger plethysmograph type ZP-2 in the study of
changes in vascular reaction resulting from exposure to low dichlorethane
concentrations. Tests and observations were made on four individuals whose
dichlorethane odor perception, as judged by replies to questions was 23*2
m . Two series of tests were performed with dichlorethane delivery for
30 seconds for the determinations of the immediate reflex effect of dichlor-
ethane on the vascular reaction, and 15 min. for the determination of the ef-
fect of the more prolonged action of the solvent. Tests were made with con-
centrations of 4 - 50 mg/m . The results of tests made with dichlorethane
concentrations of 6 mg/m delivered for 30 sec. showed that all four individ-
uals under observation experienced a constriction of the finger blood ves-
sels of short duration with a fall in the plethysmographic curve on 5th, 8th
and 10th min., specific to each individual tested; the curves returned to the
0 level after 10, 20, and 30 seconds.
Fig. 3 represents a plethysmographic record of the mid-finger of the
left hand of test individual K. It shows that a dichlorethane concentration
of 6 mg/m brought about a reduction in the volume of the finger, causing the
curve to fall 7 mm below the zero line; 20 sec. later, the curve returned to
the original level. Dichlorethane vapor of 12 mg/m changed the reaction of
-115- -
-------
the finger blood vessels in all 4 test individuals in the direction of in-
creased constriction. The plethysmograph fell 14, 18 and 20 mm and its re-
turn to the original level was considerably delayed*
Pig. 4 represents the plethysmogram of the mid-finger of the left hand
of test individual P, recorded during the-inhalation of dichlorethane vapor
of 12 mg/m concentration. Chlorethane caused the finger blood vessels to
constrict; the curve fell 12 am below the zero line and returned to the aero
position in 38 seconds. A 23.2 mg/m concentration of dichlorethane, which
corresponds to the odor perception threshold concentration of dichlorethane,
brought about constriction of the finger blood vessels in all four test in-
dividuals. The plethysaosram fell 16 - 23 mm below the zero line, to which
it returned only af ter 50 - 60 sec. Inhalation of dichlorethane vapor la
50 mg/m concentration caused the plethysmogram to fall 16, 21 and 23 mni be-
low the zero line, returning to normal only after 75 - 100 seconds.
Results of tests in which the dichlorethane delivery was extended to 15
minutes showed that concentrations of 6, 12, 23, and 50 mg/m brought about
characteristic changes in the plethysmogram of all four test individuals.
The reaction was expressed in the form of an increased pulse beat, pulse
waves, and pulse amplitude. The greater was the dichlorethane concentration
inhaled the more clearly expressed were such changes.
It can be concluded that the inhalation of dichlorethane vapor elicited
objectively observed constriction of the finger blood vessels. The degree of
vascular change caused by dichlorethane stimulation of the receptors of the
olfactory, organs odor perception, depends to a degree on the concentration of
the applied stimulator-^. The greater was the concentration of the dichlor-
ethane, the more signifj.cant were the shifts in the vascular system, which
were expressed in the form of more acute and more intense constrictions of
the blood vessels. It is concluded, therefore, that shifts in the reaction
of the vascular system objectively reflect the state of olfactory reactivity.
It should "be noted at this point that the results of our observations
are in agreement with the observations of S. Istaoianov who showed that un-
pleasantly smelling substances caused vascular constriction.
Respiratory changes affected by low concentrations of dichlorethane va-
por were also studied with the aid of the plethysmograph specially adapted
for the purpose. Pour test individuals were thus studied, Dichlorethana
vapor in the sane concentrations as in the previously discussed experiments
-116-
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Dichlorethane
.>. rietfiysmogram of test subject K taken during
inhalation of 6 mg/m3 concentration of dichlorethane.
Pig* 4. Plethysmograffi of test subject F taken during
inhalation of 12 Dg/m3 concentration of dichlorethane
-11?-
-------
were delivered for one min. Concentrations of 6, 12, 23 and 50 mg/m elicited
reflex changes in the depth of respiration which on the spirogram was recorded
in the form of increased amplitude of the respiratory wave (rhythm), as can
"be seen in Pig* 4.
The results of our experiments indicate that a 6 mg/m concentration was
the threshold concentration of dichlorethane affecting the functional state
of the vision analyzer and of the vascular and respiratory reactions which
was below the threshold concentration sensed by the olfactory organs.
We are of the opinion that the limit of maximal single concentration of
dichlorethane in atmospheric air should not exceed 4
TABLE 4.
Effect of low dichlorethane concentrations on the respiration of man.
Dichlor- :
ethane t Initial
concen- : of test
t rat i on : individual
j y. mrr /rrtJ •
4 K
P
N
M
6 K
P
H
—
12 K
P
H
M
23.2 K
P
H
H
50 K
P
H"
u
: Spirograms
: Prior to dichlor-
5 ethane inhalation
: Waves per
: 60 sec.
6
8
11
12
9
11
12
11. ._
8
8
13
12
8
7.5
11
11
8
. -. -^ :---
12
10
: Amplitude
: in mn
14
14
10
17
10
18
13
... 13 _
20
20
18
18
16
15
14
16
18
17
18
11
: During dichlor-
: ethane inhalation
: Waves per :
: 60 sec. :
6
8
11
12
9
11.5
12
12
8.5
10
13
13
9
9.5
12
14
9.5
9
12
10
Amplitude
in mm
14
14
10
17
11
25
17
18
23
22
25
24
20
23
21
20
23
25
20
20
-118-
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Determination of LArcits of Allowable Concentration of
Chlorine in Atmospheric Air.
By Iff. T. Takhirov.
Gigiena i Sanitariya 22, No. 1, 1957, 13-18.
This study was undertaken for the purpose of securing additional basic
data on the determination of limits of allowable concentration of chlorine in
the air of inhabited localities. Our first step was to establish the fact
that in the air of inhabited localities chlorine was actually present and in
what form. Previously published results by B. K, Ugryumova-Saposhnikova,
B. B. Bykhovekii and others related to chlorine "in" the e.ir of inhabited local-
ities were obtained by methods now regarded inadequate; it appeared imperative
that the subject be restudied. The analytical procedure employed in this
study was described by F. D. Krivoruchko; it is regarded as reliable and spe-
cific. The method is based on the reaction taking place between chlorine and
methyl orange in acid mediumj Cl reduces the intensity of the rose color of
the methyl orange solution: the loss in color intensity is proportional to
the Cl present and is determined colorimetrically. The sensitivity of the
method is 0.00015 mg of Cl in 2 ml of solution.
A study was made of chlorine concentration in the air surrounding a chem-
ical plant; chlorine was discharged into the atmosphere by the electrolytic
department and by departments employing chlorine in the production of HC1,
9H-C1, DDT and perchlorovinyl. The chlorine discharge was closely connected
with the specific production process used in the departments. Ninety-two
single dose air samples were collected at distances of 5» 50, 250 and 500 me-
ters on the lee side from the source of the discharge. Living quarters were
situated at a distance of 400 meters from the source of air pollution. Re-
sults of analyses are presented in Table 1.
The above data confirmed the fact that the plant's industrial discharge
polluted the air of the vicinity with chlorine. A review of literature on
this subject indicated that chlorine was universally, present in the air at
all times, especially in the air of large industrial cities. A study was
then made of the air of Moscow for the presence of chlorine. The study cov-
ered the central part of the city at distances of 1.5? 2.0 and 3.0 km from
sources of industrial discharges into the air and extended over a period of
-119-
-------
ten months. Air samples were taken 3-5 times weekly. Results are presented
in Table 2.
TABLE 1.
Maximal single concentrations of chlorine in atmospheric air
in the vicinity of the chemical plant.
Distance
in meters
5
50
250
500
1 NO. of ;
* tests *
• »
22
2
37
31
Maximal Cl
concentra-
tion in mg/m3
5.0
1.5
0.7
1.1
: Av. concn. of
: Cl (all tests)
: in mg/ia^
1-7
1.25
0.2
0.04
: Ho. of tests with Cl
: concn. exceeding
: allowable limit
22
2
18
-
(Note. 0.1 mg/rn^ is the limit of allowable Cl concentration in inhabited
localities).
TABLE 2.
•
March I
April J
May )
June I
July]
September)
October j
November J ..
Number
Total
23
26
27
38
of samples : Cl concentration
: Positive : Maximal
22 0.032
25 0,34
17 0.012
...... 37 0.028
: Minimal
0.003
0.001
0.002
0.001
in mg/m J
: Av. of all
0.018
0.008
0.004
0.012
The highest maximal concentration of Cl was 0.034 mg/m which is close
to 0.03 mg/m , the allowable limit of the average daily concentration; the
lowest minimal concentration was 0.001 mg/m and the average of all tests was
0.01 mg/m . As humidity increased the concentration of Cl in the air was low-
ered and the number of positive air samples became reduced. The possibility
of chlorohydrolysis must be considered in this connection. The highest Cl
concentration in the atmospheric air occurred in clear weather; in foggy and
damp weather, as indicated above, the Cl concentration in the air was lower.
The above tabulated results show that Cl was present in the air of Moscow even
at 3 km distance from the source of air pollution.
-120- ''
-------
A thorough study was made of the limit of allowable Cl concentration in
the air of inhabited localities by special tests. The 0.1 mg/m concentration
limit adopted by the ConEiittee was the result of a question and answer in-
vestigation of. chlorine odor perception threshold and of evidence of corro-
sive effects of Cl on metallic household objects and on the effeo.t of Cl on
the intensity of atmospheric ultraviolet radiation. The limit of Cl concen-
tration thus adopted served a temporary purpose. It was felt that the sub-
ject needed to be rechecksd by. newer methods of investigation .
The threshold of Cl odor perception was reinveatigated by special appa-
ratus which consisted of two horizontal cylinders, a system of tubes, a dos-
age administrator and mixers. The cylinders were separated from the dosage
administrators by appropriate shields. Known Cl concentrations were adminis-
tered via one of the horizontal cylinders and fresh air via the other. The
eet-up enabled the administration of any desired concentration of Cl at any
time required by the experiment. The Cl concentration constancy was checked
throughout the period of any experiment up to a full day. By appropriate and
continuous changing of concentrations and of substituting pure air intermit-
tently possible physiological effects were eliminated. Eleven persons were
under study.' Test subjects were used once daily to avoid the development of
insensitivity to the odor of Cl.
A total of 238 tests were thus performed. The results indicated that Cl
in 3 - 4 fflg/m concentrations was well sensed by the test individuals. Such
a Cl concentration caused irritation of the mucous membranes of the upper re-
spiratory passages in all test persons and brought about manifestations of
reflex cou^i and lacrimation due to irritation of the mucosa of the eyes in
some* Cl concentrations as low as 1.3 - 2.0 ng/m were still sensed by the
majority of test persons who experienced alight nasal irritation j three per*
sons complained of irritation to the mucosa of the eyes. The minimal con-
centration sensed by all ranged between 0.8 - 1«3 mg/m and the maximal con-
centration not sensed ranged between 0.7 — 1 ing/m . In the case of most sen-
sitive individuals 0.8 mg/m was the lowest concentration sensed and 0.7
the highest Cl concentration not sensed*
Considerable evidence has been presented in the literature of the fact
that irritation of the olfactory organs affected other functional phases of
man and animals. For this reason hygienic studies related to the effect of
substances emanating noxious and irritating odors need not be limited to the
-121-
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determination of threshold of odor perceptibility. It is equally important
to study the effect of such substances on the organism's reflex activity via
the receptors of the upper respiratory passages. Data thus obtained may prove
of value in obtaining more precise information on the limits of allowable
concentrations of atmospheric air pollutants. It should be borne in mind
that the maximal allowable concentration of gases emanating noxious odors
must lie not only below the threshold of odor perception but below their
threshold effect on receptors connected with reflex activity. We investigat-
ed Cl threshold effects on reflex activity related to visual adaptation to
darkness, on optical chronaxy, on respiratory rhythm and on visual-motor re-
action rate.
The effect of snail concentrations, of chlorine on visual adaptation to
light was studied with the aid of the ADlfl adaptometer. Three- test subjects
were used whose threshold cf Cl odor perception was 1 mg/m , Pure air or air
containing Cl were administered for 4.5 min. on tho 15th minute of adaptation
to darkness. A total of 75 tests were aade. The results indicated that in-
halation of Cl in 1.5 mg/m concentration elicited a heightened sensitivity
to light in all the persons tested. The level of eye sensitivity to light
returned -to its normal within 20 - 25 min. The inhalation of Cl in 0.8 mg/m
concentration had no effect on eye sensitivity to light in any of the test
subjects. The results of the experiments under discussion are presented in
Sraph 1.
It can be seen from the nature of the curves presented in Graph 1 that
changes in eye sensitivity to light became demonstrable only at and above the
threshold of Cl odor perceptibility. Concentrations of Cl which remained non-
perceptible to the olfactory apparatus had no recordable effect on eye sensi-
tivity to light any more than did pure air. It wasj thus, possible to establish
that the threshold of Cl reflex effect on the functional state of the cerebral
cortex, as determined "by the adaptometer, was in concert with the threshold of
olfactory Cl perceptibility.
Chronaxymetric studies were made next. (Chronaxy is the minimum time nec-
essary to excite a muscle or nerve tissue with an electric current of twice
the minimum potential for stimulation; more briefly, chronaxy is the minimum
time at which a current just double the rheobase will elicit contractions?
rheobase is the minimum electric potential which will elicit tissue stimula-
tion. B. S. L.) In optical chronaxy studies the differential electrode was
-122-
-------
vo
V*
£.<3 1J9f
1.99
I'"
•H
4»
•H -H
1-
no
S.1 IB U
^ 3 Cl concn, in ag/«
Fig. 1, Changes in lififrt sensi-
tivity of test subjects B» £
and P with different Cl concna*
on the 20-th min* of adaptation
4* &5V
,§• / 4 r iff 13
Teat time in min,
Fig. 2. Changes in optical
chronaiy in test subjects D, U
and P inhaling 1,5 mg/or of Cl
concentration
applied to the upper palpibra at the comer of the eye orbit and the indif-
ferent electrode was placed in the hand of the observed individual. For bet-
ter contact with the skin surgical gauze moistened with 0.8$ NaCl was placed
between the skin and the electrodes. Three individuals were thus tested;
they were asked to keep their eyes closed during the tests*
The test individuals were given a few days of preliminary training to
acquaint them with the nature of the tests. Determinations were made first
of each individual's original (normal) magnitudes of threshold response (pat-
terns); for this purpose three tests were made at intervals of 3 - 5 minutes
for the determination of the original rheobase and optical chronajcy of the
visual analyzer (optical neuro-differentiation of magnitudes and types of
optical stimulation. B. S. L.) of each individual. The final testing was
then begun. Definite Cl concentrations of pure air were administered via
the above-mentioned inhalation set-up for 3 - 4.5 min. This was followed "by
immediate repeat control tests of the rheobase and chronsoy. Duplicate tests
were then made every 3-5 minutes. The first appearance of a phosphene
(pbospbe^e is a luminous appearance caused by pressure on the eye ball; in
-123-
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this case - accomodation phosphene - is the streak of light surrounding the
visual field seen in the dark after accomodation. B. S. L^) The results of
the experiments established that inhalation of Cl in 3 mg/Q concentration
effected a prolongation of optical chronaxy as compared with the control by
an average of 0,1 - 0.12 pP. Approximately 2 - 2.5 minutes after the admin-
istration of the Cl was discontinued the chronaxy returned to the original
(normal) magnitude, considered to he a rapid return to the normal state. The
inhalation of Cl in 2 rag/m concentration prolonged the chronaxy "by 0.08 -
0.1 (iP, which is below the one above recorded. Inhalation of 1.5 nig/m Cl
concentration prolonged the chronaxy reaction by 0.07 ™ 0.08 jiF. Changes
recorded in the optical caronaxy during the inhalation of 1.5 fflfi/m Cl con-
centration are presented in Fig. 2. The inhalation of Cl in concentrations
of 0,6 - 1.0 mg/m for 2.5 - 4-5 minutes had no .appreciable effect on the
magnitude of optical chronaxy (the same as pure air), despite the fact that
1.0 fflg/m Cl concentration was sensed by the test individuals.. Inhalation
of chlorine in any concentration had no effect on the rheobase magnitude.
The effect of chlorine inhalation on the reflex reaction of the test
individuals was studied next using low concentrations of Cl, Volunteers were
first observed for an initial 2.0 - 2,5 minutes during which they inhaled
pure air. Test individuals were at no time aware of the nature of the sub-
stance administered to them. Tha pure air was then replaced by Cl-air mix-
ture of known concentration for 2.0 - 2.5 minutes: this was again followed by
the administration of pure air. Kymographic records were made of the respir-
atory movements of the test subjects. The results of the experiments indicat-
ed that the lowest Cl concentrations which were "able to elicit 'changes in the
pneumograph were at the level of 1.5 mg/m concentrations. A 1 mg/m concen-
tration of Cl produced no visible effects on the subject's respiration, even
though the Cl odor was sensed by them.
Thus, the threshold of reflex Cl effect as recorded by the pneumographic
method coincided with the threshold determined by the chronaxy method. The
method of visual-motor reaction was tried and found insufficiently sensitive,
as was shown by the fact that the inhalation of 3 mg/m concentration of Cl
for 3 minutes failed to effect any visible changes in the visual-motor activ-
ity of any of the test individuals.
-124-
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Conclusions.
1, Studies of air in the vicinity of an industrial cheiaical plant in-
dicated that the air in the proximity of the plant was regularly polluted
with Cl.
2. A study of the air of Moscow indicated that the atmospheric air of
our large cities was polluted with chlorine even at considerable distances
from sources of pollution.
3. The threshold of Cl odor perceptibility of odor-sensitive persons
was at the 0.8 stg/m level.
4. The threshold of Cl effect on the reflex eensitivity oi' the eye to
light coincided with the threshold of odor perception.
5. The Cl threshold effect on reflex activity as manifested by changes
in rhythm and amplitude of respiratory movements was at the 1.5 mg/m Cl con-
centration level, which coincided with the level established by the chronaxy-
metric method.
6. The limit of allowabl concentration of Cl (0.1 mg/m ) adopted "by
the Chief State Sanitary Inspectorate of the U. S. S. R. for atmospheric air
of inhabited localities is below the threshold of Cl odor perception and
also below the level of its reflex effect via the receptors of the upper
parts of the respiratory tract. Therefore, no recommendations are her© made
for its further lowering.
7. The maximal daily average concentration of free Cl in the air of
central Moscow was 0.034 mg/m , which is slightly above the recommended level
of 0.03 mg/m . This clearly indicates that the Moscow air can not admit any
additional Cl discharges and that the construction of new industrial plants
which discharge chlorine into the atmospheric air should be prohibited.
-125-
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Hygienic Standardization of the Limits of Allowable Concentrations
of Vapors of Gasoline in Atmospheric Air.
N. P. laaierov..
Central Institute of Post-Graduate Medicine.
Gigiena i Sanitariya, Vol. 23, Ho. 2, 1958, pp. 8-14.
This author made an experimental study of some "basic principles under-
lying the determination of limits of allowable concentration of gasoline in
atmospheric air. In this work a gasoline known as "Galosha" was used for the
greater part. This grade of gasoline is widely used in the rubber industries,
in the manufacture of paints and varnishes, in the bone processing industry
and in The manufacture or leather substitutes, etc. It is an easily evaporat-
ed liquid, especially at higher temperatures. Results of experiments per-
formed by the Institute of Labor Protection showed that when the vat contain-
ing gasoline "Galosha" was left uncovered for 11 hours and 40 minutes at 15
the loss by evaporation amounted to 21% l>y weight, at 20 the loss by evapo-
ration amounted to 48£ "by weight. In the larger manufacturing and processing
establishments the loss of gasoline by evaporation amounted to several tons
per day. In industries equipped with gasoline recuperation installations re-
covery of the evaporated gasoline was as higb as 70 - 80£. This author made
a study of the effectiveness of the gasoline recuperation installation at a
plant which used 5-5 tons of gasoline "Galosha11 daily and found it to amount
to 65£.
Recuperation of gasoline "Galosha" was practiced by only two of the
plant's departments and amounted to 500 kg of gasoline per day, indicating
that a substantial part of the gasoline used by the plant was discharged into
the atmospheric air. Studies made by this author indicated that the air in the
environs of the plant was continually polluted by gasoline vapors. Air samples
obtained were studied by the gas analyzer method in which the hydrocarbons were
combusted by a heated platinum wire spiral and converted to CO-. The latter
was absorbed by a known volume of 0.005 N solution of baryta and the excess
titrated with 0.005 K solution of HCl. From the difference in the titrations
prior to and after the CO- absorption the amount of hydrocarbons was calcu-
lated in terms of C. (See N. K. Turkel'taub, J. Analit. Khimii, 1950, Vol. V,
No. 4> also D. P. Senderikhina, Gigiena i Sanitariya, 1953; No. l).
-126-
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This author analysed over 150 single concentration air samples collected
on the lee side of the source of the gasoline discharge. It was shown that
at 150 - 200 m from the source of discharge the odor of gasoline was, clearly
sensed and its concentration ranged between 10 - 12 mg/m * Kosourov proposed
the following limits of allowable concentrations of vapors of Caucasian gaso-
lines in the atmospheric air: 50 mg/m for single maximal concentrations and
20 mg/m for daily average concentration. In the case of gasolines obtained
from Eastern petrolic oils rich in sulfur the corresponding concentrations
recommended by Kosourov were 5 mg/m and 1-1.5 n&/& • Ko reference was
found in the literature to the possible harmful effects on the organism of
such low gasoline concentrations. Evidence was found which pointed to the
specific effect of gasoline on the central nervous system (G.'B. Gerskuni,
I. S. Tsitovich, I. S. Aleksandrov and K. G. Tsibina, E. H. Levina and E. I.
lyublina, Z. E. Grigor'ev). S. G. Frenkel, I. Ya. Sosnovik, I. I. Lifshits
and many others observed changes occurring in the nervous system of those who
worked with gasoline under chronic conditions. However, according to records
in the literature chronic effects of gasoline occurred only as a result of
exposure to concentrations of 0.5 - 2.0 - 3,0 - and 5-0 rn^lit. It la not prob-
able that such high gasoline concentrations could ever be found in the atmos-
perhic air in the proximity of gasoline vapor discharges.
Ho evidence was found in the literature related to gasoline air concen-
trations as low as hundredth of tag/lit. Therefore, this author made a study
of the physiological effects of low air concentrations of gasoline. As a
first and preliminary step a study was made of the effect of chronic exposure
to 100 and- 20 mg/m concentrations of gasoline on animals' conditioned reflex
activity using the L. I. Kotlyarevskii method applicable to siaall laboratory
animals. Motor nutrition reflexes were elicited in white rats in a specially
constructed L. I. Kotlyarevskii chamber. VThite male rats of approximately the
same age and weight were used in the chronic experiments. Ten stereotype motor
nutrition conditioned reflexes were developed in each of the rats; two positive
in response to bell ringing, two positive in response to red light, one posi-
tive in response to bell ringing, one negative in response to buzzer sound,
two positive in response to bell ringing and two positive in response to red
light stimulation. After this stereotype had been well established (fixed),
tests were made to determine the animal's type of higher nervous activity, the
-127-
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effect of. differentiation extension to three minutes, the effect of ex-
ternal inhibition and 24 hours starvation.
By this method 12 rats were chosen for the experimental exposures to
the desired. gasoline concentrations. The rats were divided into three groups
each consisting of all the types of higher nervous activity groups. The
- - * j .
first group of 4 rate was exposed to high gasoline concentration; the second
group of 5 rats was exposed to low gasoline concentrations j the third group
of three rats was kept for control purposes. During the entire period of ex-
posure and recovery the control rats were kept under the same conditions as
the experimental rats. Exposures were .started after a seven day preliminary
period of acclimatization to the exposure chamber. . No deviations from normal
behavior were observed in any of the rats during the seven day preliminary
acclimatization to the test chamber.
Rats were exposed to the .effect of the gasoline in a chamber of 0.1 m
capacity six hours daily over a period of five months. The gasoline, of the
"Galosha" grade, had a sp. gr. of 0.72 and contained 2.322 of aromatic and
0.02$ of unsaturated hydrocarbons; the air in the, chamber was checked for the
concentration of gasoline 2-3 times daily. The average concentration of
gasoline for the entire exposure period calculated as C, was 106.5 nog/m for
the rats of group 1 and 21.8 mg/m for the .rats of group 2. The air in the
third chamber, which housed the control rats, was tested similarly for hydro-
carbons after the animals were in it for six hours, its concentration in terms
of C was 2 mg/m . The conditioned reflexes of . the rats were tested every
morning prior to being exposed to the gasoline concentrations. Hesults of the
experiments are graphically presented in Figures 1 and 2. The days on which
the higher nervous activity was determined are indicated horizontally: 143
days for the exposure period and 25 days for the recovery period. The fol-
lowing information was indicated vertically: the magnitudes of the conditioned
motor reaction, forming the two upper curves, and the duration of the lethal
period of the conditioned reflex reaction rin seconds .forming the two lower
curves. Changes in the conditioned reflex activity of the rats in response
to the sound of bell ringing are indicated by the solid line, those in response
to red 13 ght stimulation are indicated by the dotted line. Curve C-C repre-
sents differentiation in response to the buzzer sound, in which the vertical
lines indicate differential inhibition release. The two curves below line
C-C depict the magnitude arid the latent period of conditioned motor reactions
-186-
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In response to the tell sound and of light stimulation after differentiation
has been established. All curves of Fig. 1 are the results of tests made
upon.rat Ho. 6 of Group 1 and present a.total picture of the effect of gaso-
line "Galosha" on the higher nervous activity of the rat.
Curves in £*ig. 1 show .that changes in the conditioned reflex activity
of rat Ho* 6 began at the point of .inhibition differentiation release which
appeared on the 52d day of exposure to the gasoline concentration and could
be manifested daily thereafter. In other rats of the same Group differentia-
tion release appeared towards the end of. the third month of exposure to the
gasoline concentration; The average magnitude of the conditioned motor re- .
action in response to the bell sound became considerably lowered towards the
end of the chronic experiment, and the latent period became extended. During
the last stage of the experiments there appeared a disturbance in the inten-
sity relations (a leveling or equalizing and paradoxic phases), as was evi-
denced by the coming together of the solid and. dotted curves. In all rats of
this Group instances occurred when their motor conditioned reflexes in re-
sponse to red light became completely aborted denoting the appearance of the
narcotic phase. The results can be summarised as follows: exposure of the
rats to an average concentration of 106.5 fflg/m of gasoline "Galosha" for a
period of 5 months elicited in the rats changes in the conditioned reflex
activity, which were expressed as differentiation release, extension of the
latent period of conditioned reflexes to the bell sound and the appearance
of leveling (equalizing); paradoxical and narcotic phases. Complete return :
to normal- of the conditioned reflex activity of rats of this Group began to
make its appearance on the 14th day after exposure was discontinued (See Fig.
l), showing that the effects produced were not permanent and could be re-
versed. .
Curves in Fig. 2, generally follow the course of curves in Fig. 1; they
represent the results of experiments performed upon rat Ho. 16 of Group 2
which was exposed to 21.8 mg/m concentration of gasoline "Galosha". Ho
changes in the.higher nervous activity of this rat were observed throughout
the entire period of experimental exposure. Isolated cases of differentiation
release were observed prior to the experimental exposure as well as during the
period of recovery and, hence, could not be regarded as due to the action of
the gasoline vapors. The same was true of the behavior of the remaining rats
of Group 2 and of the control rats.
-129-
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In trying to determine limits of allowable concentrations of gasoline
vapors consideration should be given to their odors. All grades of gasoline
have a clearly expressed unpleasant odor. Gasolines which contain unsaturat-
ed hydrocarbons and sulfur compounds have particularly repulsive odors. Sat-
urated hydrocarbons and cycloparaffine have "ester types" of odors. There*
fore, a study was made of the threshold of the odor perception of three grades
of gasoline, using the method recotonended by the Committee for the Determina-
tion of Limits of Allowable Concentrations of Atmospheric Pollutants. (See
Limits of Allowable Concentrations of Atmospheric Pollutants, 1957» No. 3),
Eleven human test subjects were used varying in ages between 19-60 years,
whose olfactory functioning was found to be normal. In all 313 determinations
were made, the results of which indicated that the minimal odor-perceived
concentration of gasoline "Galosha" was at the level of 10 mg/m and the
maximal concentration not perceived by odor was at the 8 mg/m level. The
thresholds of olfactory perception of the odors of automotive gasoline A-72
and of aviation gasoline B~?0 were determined on the basis of 252 tests per-
formed on 12 normal human subjects for each of the gasoline grades tested.
The results indicated that for automotive A-72 gasoline the minimal concen-
tration perceived by odor was 6.5 mg/m and the maximal non-perceived concen-
tration by odor was 5*2 mg/m . For aviation gasoline B-7O the values corre-
spondingly were 7.6 and 7*1 fflg/m . It was, thus, determined that threshold
.concentration of olfactory perception of tte gasoline odors ranged between 6.5
mg/m (automotive gasoline A-72) "and 10 og/m (gasoline "Galosha.").
A study was also made of the threshold.effect of gasoline "Galosha" on the
reflex activity (as an indicator of changes in the functional state of the cer-
ebral cortex) using the adaptometric method, or the method of determining
changes in eye sensitivity to light using adaptometer model AIM. A total of
115 observations were made on three normal human subjects of 17 - 20 years of
age.
Test subjects had gone through a period of preliminary preparation during
which the normal curves of dark adaptation were established. They were then
made to inhale fresh air or air containing known concentrations of gasoline
vapors on the 15th minute of dark adaptation for periods of 5 minutes. Each
gasoline concentration was studied several times. The results indicated that
the inhalation of gasoline "Galosha" vapors in 100 rag/m concentrations elic-
ited no particular changes in the course of the dark adaptation curve and that
-130-
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only when the gasoline vapor concentration reached 217 mg/m did changes in
eye sensitivity to light occur in all three test, subjects, as can be seen in
Table 1. A sharp increase in eye sensitivity to light was observed immedi-
ately after the inhalation of gasoline vapors, or on the 20th minute, after
which the sensitivity to light became somewhat reduced, and towards the end
of the observation, or on the 50 - 60tU minute, reached the same intensity
as on the 20th minute. This was taken to indicate that inhalation of gaso-
line "Galosha" vapors in 217 mg/m concentration elicited some reflex changes
in the functional state of the cerebral cortex.
On the basis of the experimental results it can be concluded 'that the
inhalation of gasoline vapors in 100 mg/m concentration under conditions of
chronic exposure elicited in white rats clear cut changes in the higher nervous
activity, the intensity of which increased with the duration of the exposures,
and which disappeared only two weeks after exposure was discontinued. In the
case of man the inhalation of gasoline vapors in concentration of 217 mg/m
for a brief period of time elicited reflex changes in the optical analyzer so
far as sensitivity to light was concerned. The: threshold of gasoline odor
perception was considerably below the concentrations which elicited the pre-
viously noted changes in the functional state of the cerebral cortex; as in-
dicated by the results obtained with the Groznensk gasolines "Galosha", auto-
motive A-72 and aviation B-70, the odor perception threshold concentration
was between 6.5 - 10.0 mg/m * It appears safe to conclude from the above that
the threshold of olfactory gasoline odor perception is the most sensitive index
for the determination of limits of allowable concentrations of gasoline vapors
in atmospheric air. The thresholds of the three gasolines tested were within
a comparatively narrow range; therefore, it appears rational to propose one
limit of allowable concentration for all the gasolines. Allowing for a co-
efficient of safety, it is here proposed that a concentration of 5 nig/m cal-
culated as C be adopted as the allowable limit of a single maximal concentra-
tion of the three grades of Groznensk gasoline.
-131-
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TABLE
Initials of
person under
observation
•PW««4
L. B.
S. V.
L. Yu.
Pure air
1 ,,.
t 1J _
i At start of i At end of
s experiment t experiment
Concentration of gasoline
183
120
215
170
162
184.T
• • •
185
134
141
217
270
190
263
«rf o
a o •
• -H •
*» H
P.-H
•
o
2 s t
Exposure to vapors of gasoline "Galosha" Recuperation
period
Graph 1. Effect of gasoline "Oalosha" in 106.5 "g/» concn. on
the conditioned reflex activity of rat Ho. 6 of balanced strong type.
Average magnitude of motor conditioned reaction A-A to sound of bell,
B-B to light. Average magnitude of latent period of conditioned re-
flex a-a to sound of bell, b-b to light, C-C differentiation to buzzer.
132-
-------
**
0
o
So
ss
1-88
I"
.3
S
4* •& O
25 •
5-a
T- C^ I
< f H
•3 P*-rt .1
5
AV.-'v/t
II
at &*
- * * »- ^«.
\ ' » V "-J- "».
II
Reeup* tiae
Exposure to vapors of gasoline "Galosha"
2. Effect of gasoline "Galoeha* in 21.8 ng/a concn. on the
conditioned reflex activity of rat Jo. 16 of balanced, strong neurc-type,
Averag* magnitude of conditioned not or reflex A-A to sound of bell, B-B
to li«kt. Average magnitude of latent period of conditioned reflex
a-a to sound of bell, b-b to light, C-C differentiation to sound of buzter
-133-
-------
Increase In eye sensitivity to light on the 20th ainute
after Inhaling vapor* of gasoline "Galosha" In per cent cf
light sensitivity manifested on the 13th day before gas-
oline vapor inhalation was initiated.
Ia»e of
Pure air
Gasoline vapors conon.
in
test BUD-
Ject
L. ?.
B. V.
L. Tu.
I At start
I Of erpt.
183
120
151
t
t
At end
of ezpt.
215
170
162
t
184.7
185
134
141
{ 217
270
190
26*
Graph 3* Changes in eye sensitivity to light of subject L, Tu.
upon inhalation 2 - of purs air at start of test| 1 - of pure
air at conclusion of test; 3- gasoline in concentration of
54 mg/m^j 4 - gasoline in concentration of 184.7 BS»^i 5 - gas-
oline in concentration of 217
-134-
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Maximum Permissible Concentration of Formaldehyde in Atmospheric Air.
V. P. Melekhina.
Central Institute of Postgraduate Medicine, Moscow.
Gigiena i Sanitariya Vol. 23, No. 8, 1958, PP. 1O-14.
During the last several decades formaldehyde, in the form of formalin,
became widely used in the manufacture of plastics, formaldehyde resins, uro-
tropine, explosives, leather tanning, in agriculture and in medicine.* Formal-
dehyde has become one of the important products of the chemical industry. Ac-
cording to incomplete data, the annual world formaldehyde production ranged be^
tween 600,000 and 800,000 tons, of which over 400,000 to 500,000, or 50 - 65%
were used in the production of artificial resins.
Leakage and partial escape of formaldehyde in its manufacture and use
causes pollution of atmospheric air. However, no available data have been found
on the extent and sanitary significance of formaldehyde as an atmospheric air
polluting agent; its concentration in the proximities of specific plants have
not been determined and the effect of small concentrations on humans has not
been studied. Therefore, it was decided to obtain such information for the hy-
gienic evaluation of formaldehyde as an atmospheric air pollutant. Several
methods for the determination of formaldehyde were found in the literature.
The fuchsin sulfurous method was chosen for the possibility it offered to ex-
clude interference by the presence of other aldehydes. The sensitivity of the
method was 0.001 mg in 3 ml. In some tests the chromotropic method was used
as a check or control method; it yielded analogous results. Results of tests
demonstrated that for the determination of high concentrations of formaldehyde
6-8 liters of air should be- aspirated, and for lower concentrations 60-70
liters of air should be aspirated. In the first case the limit of determinable
formaldehyde concentration was 0.2 mg/m and in the second case - 0.014 mg/m .
Air samples were collected by the aspiration method in the vicinity of a
chemical plant manufacturing formalin and formaldehyde resins. The plant was
not equipped with air purification installations. Dwellings were situated at
distances of 50 - 75 m from the plant. The odor caused by the plant's dis-
chargoa was always perceptible in this area. Samples were collected on the
windward side of the plant, and determinations were made for maximum single
concentrations. Results are presented in Table 1. Thus, it was established:
-135-
-------
that around formalin manufacturing plants formaldehyde concentrations up to
0.042 mg/m were detected in the atmospheric air at 1000 m from the plant.
laany indications were found in the literature regarding the presence of alde-
hyde, and in particular of formaldehyde in exhaust gases of Diesel engines.
Accordingly 45 samples were collected of Diesel engine exhaust gases, directly
from the exhaust pipe of a running motor vehicle, and also of the air on high*-
ways during intensive automobile traffic. Studies were cade of exhaust gases
of cars using Diesel engine fuel and gasoline; the total of aldehydes and for-
maldehyde were determined. It was found that the exhaust gases of Diesel-pro-
pelled motor vehicles contained from 49 - ^78 mg/m , with an average of 115
mg/m ; the exhaust gases of motor vehicles using gasoline contained from 6 to
•a •
9 cig/m of aldehydes.
Investigations of atmospheric air pollution with formaldehyde caused "by
auto traffic were carried out on sidewalks and in neutrnl lanes of Sadovyi
Circle, 1-2 meters from a running Diesel motor. Fifty percent of the tests
were positive for formaldehyde, which varied between 2 to 10 mg/m . The mean
formaldehyde concentration of air samples 'from the sidewalk and the neutral
strip was 2.6 mg/m , showing that at the given distance the formaldehyde con-
centration in the air was 44 times lower than in the immediate exhaust gases.
Thus, the possibility of atmospheric air pollution around plants which dis-
charged forrualdehyde and in streets with prevailing automotive traffic was
established.
As the .next step, a study was made of the hygienic significance of the for-
maldehyde air concentrations found. Threshold of olfactory sensitivity was in-
vestigated first. V. B, Isachenko -; showed in 1940 that the threshold of formal-
dehyde irritation effect to man was 3 mg/m . A slight irritating effect to
the mucous membrane of the eye and of the mucosa of the upper parts of the
respiratory tract ivas observed in a room in which the formaldehyde concentra-
tions were between 0.95 and 1.0 m^m (as reported by G. 1£. Shifman). A 25
m concentration caused strong irritation of the mucous -lining.
Determinations of the threshold of olfactory senstivity and of reflex
response were, made by the method of optical chronaxy, adaptation to darkness
and pneumographically, according to recommendations by the Committee on Limits
of Permissible Concentrations of Atmospheric Pollution in Vol. 3, 1957? P. 124.
The threshold of olfactory senstivity was determined in 12 test subjects, 19-
-136-
-------
65 years of age. As a result of 269 observations it was established that the
threshold of olfactory senstivity to formaldehyde ranged between 0.07 and 0.11
ag/m * The maximum non-perceptible concentration for the majority o.f the in-
dividuals was 0.05 rag/m , as can be seen in Table 2.
The threshold of reflex response effect as determined by optical chrcmaxy
was studied with the aid of chronaxymeter GIF model 1949- Investigations were
conducted on 3 of the individuals under observation, aged 17 to 55 years. The
threshold of olfactory sensitivity to formaldehyde of two persons was 0.07 and
•5 *
of the third 0.11 rag/in . The first 5 ~ 7 days were devoted to training in the
technic of the test procedures "by making the test subject inhale fresh air; on-
ly after persons became well adjusted to the general steps of the test proce-
dure were actual determinations begun for chronaxy and rheobase effects through
inhalation of known formaldehyde concentrations. Formaldehyde was administered
on the sixth minute of adaptation and readings were made every three minutes be-
fore and after formaldehyde inhalation for 15 minutes. Intermittently persons'
response was checked "by fresh air substitution to ^uard against possible con-
ditioned reflex response as the result of environmental influence.
(Definitions; flheobase: The minimum potential of electric current nec-
essary to produce stimulation; Chronaxy; The time required for the excita-
tion to a nervous element by a definite stimulus; the minimum time at which a
current just double the rheobase will excite contraction).
An analysis of the data showed that formaldehyde in 0.08 mg/m concentra-
tion caused in two persons under observation shortening of chronaxy. The rheo-
base of the third' person was changing towards increase in latent period begin-
ing with 0*1 rag/m and upB The rheobase of formaldehyde reflex reaction was
•>
close to the threshold of olfactory perception and corresponded to 0.08 mg/m .
3)ata obtained with test subject S are graphically presented in Fig. 1. The
O.O7 mg/m concentration- was carried out with the help of adaptometex- AJS5-52
in a dark room at normal temperature and humidity, free from extraneous odors
and with prevailing quiet. During the first few days determinations were made
for normal adaptation curves for each of the individuals for comparative and
control purposes. Results of, final tests showed that high formaldehyde con-
centrations, such as 1.71 rag/m caused a sharp decline in sensitivity to ligiit
in all three examined persons. Formaldehyde concentration of 0.3 mg/m also
caused a delay in adaptation to darkness in 2 persons. Concentration of 0.2
-137-
-------
mg/m produced an Increase in sensitivity to light in all the observed persons,
and the 0.098 mg/m concentration effected no changes in the curve of adapta-
tion to darkness, as can be seen in Fig. 2.
Investigations of the influence of formaldehyde on respiration of three
persons were conducted with the aid of an ordinary pneumograph. No noticeable
changes in the frequency and rhythm of respiration were observed with concen-
trations below 2.5 mg/m .
Taking 0.07 mg/m ae the threshold concentration of olfactory perception
and 0.08 rag/in of formaldehyde as the point of reflex effect on optical chro-
naxy in conjunction with other pertinent data, it was concluded that the max-
imum permissible formaldehyde concentration in atmospheric air should not ex-
ceed 0.0^5 mg/m .
Conclusions.
1, The atmospheric air in the vicinity of the chemical plant under in-
vestigation was systematically polluted with formaldehyde, the concentration
of which was as high as 0.04 mg/m even at a distance of 1000 meters from the
plant.
2. The threshold concentration of olfactory sensitivity to formaldehyde
for the majority of persons under observation was 0.07 ns/0 . A concentration
of 0.05 mg/m was non-perceptible to most sensitive persons.
3. The threshold forrcaldehyde concentration affecting reflex reaction as
determined by the chronaxy method was 0.08 mg/m , and 0.07 ^g/m was the sub-
liminal concentration.
4. The formaldehyde threshold concentration of cortical reflex effect -
obtained by the adaptometric method rested in most sensitive persons at the
level of 0.098 mg/m &
5. In studying the influence of small or low formaldehyde concentrations
on man the method of determining threshold concentration of odor perception
was the most sensitive, the result being 0.07 nie/ni . Maximum permissible sin-
gle formaldehyde concentration in atmospheric air should not exceed 0.035
3 • —
6. The sanitary clearance zone established by our sanitary regulations
around plants manufacturing plastics, such as carbolite, celluloid, bakelite,
vinyl chloride, etc. and formaldehyde resins in volumes up to 200 tons annu-
ally is regarded as not adequate] it should be not less than 500 m wide where
-i3d-
-------
purifying installations are in proper operation and 1000 in where such instal-
lations are non-existent.
7. Plants discharging formaldehyde into the atmospheric air rcust use
scrubbers of the water-spray type.
8. Pollution of the air of lar^e cities with aldehydes, &M in particular
with formaldehyde, coming from automotive vehicles brings into sharp focus the
imperative need to Improve automobile engine designs, checking internal com-
bustion motor performance followed by expert adjustment which should materially
reduce the degree of air pollution by the constantly increasing volume of auto-
motive traffic.
Table
single formaldehyde concentrations near chemical plant.
: Distance ;
1 from :
• n j. j *
| plant in t
t meters i
s 5
250
500
1 000
No* of
.
samples
33
25
27
No* above
test
. . ,
sensitiv-
ity limit
33
17
4
: Concn.
t
! Maximal
V
0.578
0.155
0.042
in
i
i
mg/m
Average
0.211
0.063
0.0055
*
t
s
*
No* of samples
exceeding limit
able concentration
33
17
3
Table
Formaldehyde perception threshold*
I Test subject I Number of
1 (initials)
1
«-
H. I
A. P.
A. 3>.
E. B.
B. M.
Tu. A.
S. Ta.
«." P.
M* R.
B. P.
K. 0.
T. A.
t Formaldehyde concentration* :
: 1
| observations ] Minimum : M^yi rmirp non— :
1
i
28
26
28
27
28
23
27
27
22
21
8
4
| perceptible j
i :
0.07
0.11
0.07
0.07
0.07
0.07
0.07
0.07
0.08
0.08
0.08
0.08
perceptible j
s
0.05
ojo8
0.05 ,
0.05
0.05
0.05
0.05
0.05
0.07
0.05
0.05
0.05
-139-
-------
Observation time in minutes.
Pig. 1. Changes in optical ohronaxy of test subject S at
different formaldehyde concentrations.
pure air w* w w V
Formaldehyde concentration in mg/m
Fig. 2. Changes in eye^ sensitivity to light at differ-
ent formaldehyde 'concentrations after 20 min-
utes of adaptation.
L., S., E. - Initials of test subjects.
-------
The Utilization of Air Dust and Smoke Purification Equipment,
9jr
V. 0. Uatsak.
From the Central Sanitary Laboratory of Moscow.
Giglena i Sanitariya, So. 4, 27-35, 1950.
Industrial discharges of boiler ar.d heat and power plant furnaces are among
tne predominant sources of city air pollution with gas, dust and fly ash; this
is particularly true of plants which burn pulverized brown coal. To a lesser
degree air dust pollution comes from poorly maintained highways and streets;
where automobile traffic is heavy, air pollution/ with dust may reach high con-
centrations in large towns, particularly if the streets are cleaned and washed
infrequently. Furnaces of boiler-operated plants, and particularly of heat and
power plants and of manufacturing and processing industries, which emit dust in-
to the atmosphere are becoming potent factors in air pollution with dust and
smoke, Large industrial towns are always covered by a screen of discharged
smoke and dust.
The generally accepted classification of atmospheric air pollutants such
as dust and smoke, according to the diameter of the suspended particles is some-
what artificial. In nearly all dusts liberated as a result of industrial proc-
esses, such as grinding of substances or cleaning.of metal articles by sand-
blasting, particles smaller than 10 n are present along with larger particles.
The smoke of boilers fired with pulverized coal also has comparatively large
fractions of fly ash. Obviously the removal of larger particles of dust can
be accomplished more effectively than of smaller particles. The term efficiency
as applied to air or gas purifying equipment refers to the ratio between the
weight of dust removed and the weight of dust in the air prior to purification,
without taking into consideration the size or the degree of removal of individ-
ual fractions. Such a concept of efficiency is misleading since it is the frac-
tions which range between 0.2 to 5 M- which are most difficult to remove, and.
which affect the organism unfavorably, due to the ease with which they penetrate
into the alveoli of the lungs where they become fixed*
If a dust-retaining installation collects chiefly the large diameter frac-
tions, then even with a high, efficiency of dust removal the result is unsatis-
-141-
-------
factory from a hygienic point of view. To .demonstrate this point an analysis
was made of the dust generated during carborundum grinding of a plastic sub-
stance known as "pobedit". The resulting dust wae analyzed according to diam-
eters of free particles classed into four groups as follows* up to 2 u, from
2 - 5 Mi from 5 - 10 p and from 10 - 25 HJ and of dust agglomerates into two
&
groups i up to 10 \i with an arbitrary average of 5 H> and above 10 p with an
arbitrary average of 15 p. Particles of each group were counted and weighed
and results recorded in percent. The data presented in the Table are self-
^-explanatory. Assuming that the gas-purifying installation retained all the
dust fractions with diameters of 10 11 and over, tjid only 50£ of the fractions
with diameter up to 10 p, the efficiency of the installation would be (47*94 x
2) + (2.63 7 4) * 95*88 + 0.66 » 96.556. In other words, calculated on the above
basis the efficiency of the purifying equipment would appear to be very high;
at the same time the greater number of email-diameter highly dispersed dust
particles, that is particles of the size which are meet penetrating and most
active physiologically, remain suspended In the gas or in the air.
Ratios between results of count and gravimetric fractional percent
determinations. Samples taken at working points
and breathing level.
Ratios of
fractions
Count method
Gravimetric
method
I
1
s
Up to
2
7.6
. . ... .
0.21
Size
s From 2 s
i to 5 I
5.4
.. .
0.58
of dust
From 5
to 10
2.6
~
2.69
particles
i From 10
I to 25
2.6
45.95
in &i
i Agglomerates
t Up to 10 t
8.0
2.63
Over 10
5.4
47.94
Wet grinding and polishing arc generally regarded as dust-free operations,
and wet grindj rig-wheels, as a rule, are not equipped with dust suction apparatus.
In this connection It has been shown that highly dispersed particles generated
*,in the wet grinding and polishing operations remained suspended In the air in
. - . 3
concentrations as high as 5 ~ 7 Bfi/B . Where a high degree of air purification
is achieved sanitary regulation does not prohibit its reoiroulation, thereby
•„ saving the cost of winter fuel required to heat the outside air used In tba
ventilation of the workshops.
Purification of air and of gases £rom dust and smoke is practiced for hy-
gienic and national economy reasons. Thus, in purifying air coming frcea dost-
-------
creating production departments, such as rolling mills, the recovery of valuable
waste products is of equal importance to their removal for sanitary-hygienic
reasons. The same is true of installations for the recovery of dust from pul-
verizing and m* •«•* «g plants of the aniline dye industry, etc. Thus, the high
degree purification of ventilation air performs the functions of sanitation
and national economy. The purification of ligfrt and generator gases from dust,
smoke and tar aerosol, the removal cf dust from gases resulting from pyrite
calcination are of importance to industrial economy* The purification of smoke
*
gases from fly ash is of importance primarily to sanitation, and it may he done
also for industrial purposes. The Stalinogorsk State Regional Power Plant
(GBES) emits into the air hundreds of tons of fly ash containing about 2$% of
aluminum. The utilization of such ash as raw material for aluminum production
fully justifies the setting up of appropriate dust-collecting equipment.
In purifying air and gases from dust, the following factors must be taken
into accounts a) the weight of dust, which may vary from a few milligrams to
tens of grams per m of air or ga&j b) the size of dust particles and their
weight/number ratios; c) the chemical composition of the dust and its suscepti-
bility to vetting by water* oil and similar fluids. Relating means of purifying
air from dust and smoke can be divided into dry and wet methods*
Dry purification of air* Settling chambers are used at present chiefly for
the recovery of dust particles 50 to 100 p or larger, such as dust froa leather
scraps from shoe manufacturing, textile mills, etc. where the shops are in some
cases provided with wire netting. They are effective only where the dust par-
ticles are large and are of solid consistency* The effectiveness increases with
the surface areas of the wire screens and decreases with increase in the rate
of air circulation and of the height from which the particles descend. To in-
crease the effectiveness closely spaced horizontal shelves can be installed in
the shops* In the early days of sulfuric acid production, similar wire screen
installations were used for purifying the gas coining from pyrite furnaces. The
sizes of cinder dust particles retained reached 10 - 20 mp. The efficiency
seldom exceeded 50 - 60?, although the concentration of the dust in the gas
reached 10,000 me/a . Such equipment has been replaced by electrostatic pre-
cipitators.
Inertia dust separators* The separation of dust particles by inertia de-
pends upon the fact that the specific gravity of dust is 1000 times as great
-143-
-------
as the specific gravity of air* When the direction of air flow is changed
suddenly, the dust particles maintain their previous direction and become sep-
rated from the air or gas* On the "basis of the size and. concentration of the
suspended dust particles it is possible to determine a set-up by which close
to 10056 separation of particles of specified sizes can be attained* However,
the Inertia-dust separators cow in use, such as cyclones, multicyclonea and
inertia filters, operate efficiently only within the limits of specified size
particles. Snailer and larger diameter fractions slip through the filters,
and have to be filtered out by other types of purifiers. Some of the dust which
adheres to the walls becomes detached and is picked up by the gas or air flow,
particularly if the bottom of the cyclone is not tightly closed. Even if the
cyclones are properly installed and controlled, they should not be used for the
removal of dust with particles of less than 30 p. They are effective for re-
covering large fractions of dust and fragments of saw-dust and wood shavings.
Hulticyclones operate at a higher efficiency, IB the case of cinder-dust
from roasting furnaces their efficiency Is ?0£* Multicyolones are used for the
removal of fly ash from boilers burning pulverized coal, with an efficiency of
f
&5 - 70£* High concentration dust with a predominance of large diameter frac-
tions can be effectively removed by multicyclones; thus, the efficiency of a
muiticyclone used in connection with a coal kiln at the Voznesenskii Chemical
Combine wae 96£. A small centrifugal filter designed by I* S* Rozeakrantz was
installed in the laboratory of the UIUIF experimental plant (Scientific Re-
search Institute of Fertilizers and Insecticides) operated at 100$ efficiency;
similar results were reported toy Grishchenko and others* It can only be hoped
that such reports will be checked and verified under working conditions*
Porous filters* The separation of dust \jy fine-pore materials, such as
heavy fabrics or filter paper, has beon used widely as a means of purifying
factory air and as masks for the protection against the inhalation of dust.
The most widely used fabric filters are the sleeve, or bag filters, which may
reach 9@£ efficiency particularly in the separation of fibrous dust. In some
cases, as in textile plants, fabric filters are used for the purification of
reoirculation air* Complete purification of air cannot be achieved by fabric
filters. The best fabric filter has pores of 15 p and can not retain dust par-
ticles of 1 to 5 p. Dust particles of less than 1 p are well retained by fab-
ric filtersj this is thought to be due to the fact that dust particles of 1 p
-144-
-------
or lees are endowed with Brownian movement and do not move in a straight line.
It has been noted thai sleeve or bag filters were most effective in eases
where the dust contained a high percent of relatively large diameter fractions}
such fractions soon fill in the large pores and increase the retention capacity
of smaller particles. This is verified by the gradual increase in the origi-
nally low pressure drop. In cases where small fractions predominate the fabric
pores become clogged, the pressure drop risesf the fabric begins to stretch, and
its surface increases, this :Ln turn increases the pressure drop while .the fab-
^
ric load decreases. Similar instances were observed in connection with sleeve
or bag filters used in the Shohelkov plant for the purification of air from the
dust of arsenic salts after the latter were ground in Rem mills; such dust par-
ticles were less than 10 p in diameter. The pressure drop was more than 200 mm
7 O
of water at an air load of 40 - 50 m /hour per m of fabric. Examination showed
*
the bags to have been stretched, and the fflmfring apparatus proved ineffective
because the bags became too loose. This occurred in the face of the fact that
at this plant the fabric filters were well cared for; they were changed every
1.5-2 months and laundered, and the bags shrank to the original size. The
dust concentrations exceeded 1,000 mg/m . In the last 10 years fine-pore cel-
lulose filters have been proposed; but their use has been limited to the prepa-
ration of gas masks and the like*
Electrostatic preoipitatcrs. Gas and air purification by electrostatic
preoipitators was looked forward to with great hope. It aas thought that such
apparatus would remove completely dust, smoke and fog aerosols. Laboratory
tests showed that 100£ of fine cmoke, suoh as tobacco, could be removed. How-
ever, in many instances the use of electrostatic preoipitators under industrial
conditions did not yield the hope for high efficiency. For instance, where elec-
tric precipitatorg replaced sedimentation chambers in the production of sulfuric
acid, the gas entering into the tot?ors after electric purification still con-
tained up to 200 me/in of dust, the initial concentration having been 10,000
mg/m ; it clogged the opening attachments of the towers which had to be cleaned
periodically. The use of electric procipitatora in electric power stations for
recovering fly ash from furnaces burning pulverised coal was 90£ effective} this
is not adequate in view of the enormous total quantities of fly ash resulting
from the combustion of low-grade coal high in ash.
Acid fogs or aerosols formed during sulfuric acid concentration cannot
be adequately precipitated even "by two electrical precipitators installed in
-145-
-------
series. The pressure drop of electrostatic precipitators is low} it is protable
that the preliminary removal of large dust particles in settling chambers, cy-
clones, eto. would increase their efficiency. Large duat particle agglomerates
may prematurely discharge the dielectric electrodes} in addition, dust precipi-
tated but not removed from the range of the air current can become free and be
carried off by the moving air. The cost of operating electric preoipitators is
hot great, but the cost of the equipment is high; it requires much metal for
its manufacture, which limits its application. Electric preoipitators are chiefly-
used for technological purposes} their use in the purification of air is still
limited.
Wet purification,
Water spray washing. Water washing wets the suspended dust and effectively
removes it from the gas; in many instances it is 10Q£ effective. The purifica-
tion of industrial wastes from dust is done frequently in scrubbers mostly filled
with porous materials such as gravel, coke, Raschig rings and the like, which
increase the contact surface of the dust-ladan air with the water. Then dust-
containing air passes through a scrubber, the change of direction causes dust
to separate from the air current by inertia and to adhere to the wet surface
of the apparatus, as can be seen in Fig. 1. Scrubbers are of large dimensions
and are expensive to install. In addition, they have a high pressure drop. In
other scrubber types the purifying is done by bubbling gas or air through a lay-
er of fluid. Such scrubbers are highly effective, but develop a pressure drop
300 - 500 mm of water} this limits their application to the purification of
emission gases or vapors. .
At present wet cyclones and gas washers built on the principle of air con-
ditioners are successful scrubber competitors. They have a lor pressure drop,
but require greater quantities of atomized water. Fig. 2 is a drawing of such
a purifier which was tested in the tobacco factory "Tava:i; it was equipped with
spray noasles and removed close to 100$ of the suspended tobacco dust. The air
thus purified was cleaner than the outside air, and was recirculated.
A high degree of dust separation was observed in the air of the Orokhovo-
Zunevskii briquet plant where wet cyclones were used. Effective purification
of air from some types of dust was attained by the use of wet vacuum pumps
The air aspirated V such pumps coming into intimate contact with the water
-146-
-------
Fig. 1. Wet scrubber
1. Polluted air| 2- purified
air} 3 - furnace bars} 4 -
packing (Easchig-rings, coke,
gravel, etc.; 5 - outflow of
used fluid} 6* - fresh water
inflow} 7 - distributing de-
vice.
entering the pump rotor la freed close to
100£ of the suspended dust. Thus, In the
areenio department of the Shchelkov&k chemi-
cal plant such pumps were used for the crea-
tion of vaoutas and aspiration of air from the
mills and the purified air returned to the
workrooms. Fabric filters used previously
left considerable quantities of arsenic dust
in the air, frequently reaching several hun-
dred milligrams per a , and under faulty con-
ditions of operation more than 1 g/m . In
contrast, the air purified by vacuum pumps
contained no arsenic dust. An analysis of
the water passing through, the pumps disclosed
arsenic content up to tens of milligrams per
1 li of water, indicating that the purifica-
tion of air from toxic dust by pump HUK was
100*.
Oil filters. The retention of dust by
oil can be highly effective in removing dust
difficult to wet with water. However, wet scrubbers, and in particular the
oil wetting type, are seldom used in practice; they are used mostly for the
recovery of vapor forming substances. Viscose filters are used in the purifi-
cation of air for recirculation. Such filters consist of several parallel
viscous plates, as in the case of the Tronov filter, or of compartments filled
with Raschig rings previously washed in oil. Such filters will purify the air
from aerosols, such as tar aerosols generated in the production of consumer gas.
Such filters will remove 90i or more of kerosene aerosol. To be able to attaiu
such high air purific»tiui oil filters must be properly installed and operated.
To attain higher efficiency the standard sections of the viscous filters can
be filled with Raschig rings of not more than 15-20 mm, nor should Raschig
rings be placed in a vertical position. Oil filters should not be used for
the purification of air containing more than 10 mg/m of suspended particulatesj
under conditions of high duet concentrations the layers of oil soon become
coated with dust which cuts their efficiency to 5<#» Present experience in-
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Fig. 2. Plan of air purification system in
tobacco factory "lava*.
*
1 - Exhaust ventilation in crushing (cutting) section; 2 -
intake ventilation in crushing (cutting) section* 3 - cross
section of viscous filter; 4 - cross section of water spray
device; 5 - slide valyes; 6 - spray nossles; 7 - separator;
8 - heating device i 9 - water supply pipe I
10 - slurry the construction of which is shown schematically
in Fig. 4» could be used acre appropriately for the pmrification of air with
20 mg/« of dust.
The future of ...the struggle against air dust pollution and research in
this field. Th«* preceding discussions indicate that many air purification
means are available which are highly efficient* Among such methods mention
should, "be roade first of the wet dust removers* the possibility of using wetting
agents other than water should be investigated. Methods used for the removal
of smoke and fog from the air have beer, found reasonably adequate* nevertheless,
many phases of the problem remain unsolved} for instance, sulfuric acid aerosol
can not be removed completely by any of the existing methods. Multicyclones
and electrostatic precipitators do not remove fly ash completely at electric
power stations. In spite of the removal of 70 - 9056 of fly ash in modern
heating and power plants, they still constitute the principle sources of city
-148-
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Fig. 3. Flan of pneumatic vacu-
um connection with vacuum pump
SIC
- Collector for pneumatically
transported material} 2 — bag
filter; 3 - pumpj 4 - motor } 5 •
w&ter separator.
'/ .N
Panel,
filter
Heater
Ventilator
air pollution with fine dust. Xt would
appear timely to study the shortcomings
of multicyclones and electrostatic pre-
cipitatora. A study should also be made
of the poasibility of using wet air and
gas filtration more extensively. In the
production of dry ice use is made of the
contained in furnace gases completely
freed from smoke and in part from sulfuric
acid by passing them through water.
Recant investigations showed that
printing establishments and plants which
uss aelted lead polluted the atmosphere
with, a stable lead aerosol. In the ab-
sence of sanitary clearance
zones between the plants and
the residential buildings, the
emitted air must be freed of the
lead aerosol for the protection
of the health of those living
in nearby villages as well as
for the protection of the health
of the workers.
Fig. 4. Plan of intake-air purification
with paper filter.
1 - Outdoor airj 2 - "ovafcl*. panel? 3 -
revolving drum} 4 - netted screen* 5 -
trough with mineral oil5 6* - cover or
jacket| 7 - guide rods.
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Efficiency of Mineral Wool Filters,
T. S. Karacharov and Te. I. Vorontsova.
From Institute of Labor Hygiene and Occupational Diseases, Academy of
Medical Sciences of the U.S.S.R.
Gigiena i Sanitariya, No. 6, 29-35> 1952*
Electrode arc welding constitutes a source of considerable air pollution
with finely dispersed duat, which, in addition to the relatively harmless fer-
ric oxide, contains toxic compounds of manganese and fluorine.
In welding shops of heavy machine construction plants, particularly those
of transportation machinery, where manual welding is widely used, extensive
air ventilation is instituted to reduce the air dust concentration to the limit
prescribed "by regulation for workshops. Such extensive air ventilation ia
costly because of the high consumption of electric energy and of the necessary
preheating step. Economy may be achieved only by means of air reoirculation
and by the effective elimination of dust in the recirculation process. The
solution of the problem of air recirculation in electric welding shops must be
based on a detailed study of conditions and on the appropriate choice of dust
filters; in this study mineral wool was chosen, manufactured by a Moscow plant,
The wool fibers were 7 - 20 ti thick, varied in. length from 1 - 10 cm and were
treated with 0»5 - 1»3£ °f bitumen; the fibers became brittle and broke easily.
The thickness of the filter layer varied from 15 to 20 mm.--. -. .
Testing of the filter pads efficiency was conducted in two adjacent labora-
tory rooms of 100 m total capacity. One of the rooms housed the welding arc.
The filter coil, 0,5 x 0.3 m, was located close to the ceiling of the room, as
shown in Fig. 1; it was connected by means of a sheet Iron air conduit to a ro-
tary fan (3) installed in the other room. Pig. 1 is a schematic drawing of the
installation. The air polluted "by the aerosol coming from the operation of the
manual welding torch was sucked by the electric fan via the ceiling filter cell
into the adjacent room. For the duration of the experimental tests the instal-
lation operated at 100& recirculation.
The dust concentration was determined by special adapters, one of which was
installed in the upper part of the first room approximately 0.5 m from the fil-
ter cell; additional two adapters were installed in the middle of the second
-150-
-------
a^^^^^^^
First rooa
Second room
1
3
Fig. 1.
2 - &ir conduit
ventilator ; 4 - motor j
5 - air distributor.
room, one 1.5 and the other 3 m above
the floor. Tests were made with two
siees of filter pads, 0.5 x 0.5 m and
0.5 x 2 mj the 0.5 x 0.5 m filter pad
was placed over a wire screen of the
filter cell* the 0.5 m x 2.0 m filter
pad was placed over a specially con-
structed edapter which consisted of
two comb-shaped frames of equal dimen-
sions, as shown in Figure 2. The frames
were overlaid by wire gauze. The miner-
al filter pad was placed over one frame
in sections in a wavy or zigaag manner,
and the second frame was placed over it,
so that the layer of the mineral wool
was held between the two sets of wire
gauce. The two sections were then fastened together by thumb screws, and the
whole placed into a tightly fitting device to prevent air leakage.
The efficiency of the filter layer was determined "by comparing the concen-
tration of dust and the content of manganese oxide in the air before and after
Dust concentration was determined gravimetrically and ty count. In
the first method use was made of cotton and ash-
free paper filters in glass adapters. A metal
adapter designed fcy Ye. I. Vorontsova, of the
Dust Laboratory of the Institute, was used in
collecting the sample for dust counting. An ex-
act quantity of high quality steel electrodes,
brand CWM-5, was tairned for the experiments. Each
experiment lasted 40 to 45 minutes. The air passed
through the filters at 0.5 - 1 m/sec. The test
time for aa individual filter was determined by
the rise in the pressure drop and the consequent
fall in the rate of the air passing through, the
filter! *&« lower limit being 0.3 to 0.4 m/sec.
2. Average results of 16 tests made with two mineral
-------
filters, one weighing 600 and the other 400 g, showed that, with an initial
dust concentration of 8 - 12 mg/m and a pressure drop of approximately 44 am
of water, the dust-retaining capacity approached 8055. The results also showed
that a rapidly developing "fatigue" was a specific characteristic of mineral
filters, as shown in Figure 3. The retaining capacity of the filter pads waa
20 - 21 g for the entrance cell of the filter, or 80 - 87 g per 1 m2 of the
filter material. At an assumed rate of air passing through the filter of 0.5
m/sec (or more), which would amount to 1,800 m /hour per m of the filter and
an average dust concentration of 12 mg/m , such a filter should remain in op-
erating condition from 4 to 5 hours, and even then, during the last two hours
its pressure drop would rise to 60 - 80 mm of wacer., Such filters are inade-
quate for the needs of arc welding shops. With an average dust concentration
of 7 mg/za , such filters could remain in operation for a period of 8 to 10 hours
before requiring replacement*
It is possible to enhance
the dust-retaining capacity
and the time of effactive op-
eration of t-he filters, while
retaining the original cell
dimensions, by increasing the
surface area of the filter to
a maximum by a method shown in
/ j i i f r / t
Duration of filter service
Fi*. 3. Fatigue curve of bitumen treated «*_..,,.,..
* ndSral wool filter «*«* 2« »*• mteruig s
I - Filter layer 0.5*0.5 » weighing &>0 g| <* **** o-ll »as eo.ua! to 1
pressure drop 43-44 m« water column* orig-
inal air dust concentration 12 mg/wPj
II - Filter layer weighing 400 g; pres-
sure drop 43-44 am water column} ^original
air dust concentration 8
length of the filter pad
^i^* o o
was 2 m and its weight 2.2 -
2.3 kg. Two series of t&sts
flMfc
of 17 experiments the rate of air passing through the cell was maintained at ap-
prorimately 1 m/seo, and during the second series of 20 experiments, approxi-
mately at 0,5 m/8ec- ^e initial dust concentration in the first room varied
"1
from 5 to 9 £&g/m throughout the tests. Results of the test showed that, by
increasing the filtering surface 4 times, the duration of effective operation
of the filters aas markedly prolonged. With a rate of air not less than 0.5
m/aec passing through the filter and an initial dust concentration of 7 - 9
-152-
-------
mg/m , a mineral filter pad with a surface of 1 m inserted in a cell of 0.5
L
0.5 m operated efficiently up to 16 hours, or two work shifts. Best results
were obtained in the first series during which 9*600 m of air, having an av-
erage dust concentration of 8 mg/m , waa passed through the filter. No further
testing was possible due to the great rise in the pressure drop. During the
second series of tests 7>150 m of air, having an average initial dust concen-
tration of 6.5 nfi/0 » was passed through the filter. The dust retaining effi-
ciency, determined gravimetrically, was about 89£ for the first pad, and up to
98& for the second pad at a lowered rate of flow. Figure 4 shows pressure drop
curves for 1 and 0.5 m/seo rates of filtering.
Both curves show that
after the pressure drop
of a filter reached 70 »
80 mm of water, further
utilization of the filter
becomes impossible because
of the continuous rapid
rise in the pressure drop.
These phenomena were ob-
served after 11 to 12 hours
of operation at a rate of
1 m/sec, and after 18 hours
at a rate of 0.5 m/sec.
* * J f ? * * ^ " '* a " a
Filter service time
Fig. 4. Filter pressure drop.
- At air flow rate of 1 in/sec. II - At air
flow rate of 0.5 »/seo.
Averages of dust- retaining capacity of all experiments made were 69 g per single
cell of the first filter layer and 45*5 S ^°r *he second layer.
The count method could not be used in this efficiency evaluation due to
the high dust content in a large number of samples collected in the first room
before filtering. Generally, this method indicated a lower dust retention at
the beginning of the operation and a gradual rise as the air filtration con-
tinued. The dust counts in the second room, after filtering, were higji throu^i-
out the experiments, fluctuating between 3,000 and 10,000 particles as regis-
tered "by counter ^f-2. 99>6 of the dust counted before and after filtration
measured up to Iji in diameter. Arc welding aerosol is toxicj therefore, it is
important to know its contant ty weight per 1 m of air in terms of chemical
components. In the experiments here reported the content of ;nanganese in the
tested air varied from 0.018 to 0.03 mg/m .
-153-
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The,filtering efficiency and the dust-retaining capacity of mineral vool
was compared with that of lignin filters of 4 and 6 layers. One test was made
2 2
with the filtering area of 0.25 u and the other with 1.0 m . The results
showed that lignin filters, had a dust-retaining capacity of about 90£? but that
saturation, or fatigue, appeared in a short time* Soon after the first experi-
ment! the rate of air passing through the filter was only 0.4 ra/seo. Thus, the
dust-retaining capacity of lignin fibers proved to be below that of layers of
mineral wool, as seen from data presented in the following Table.
IJype of filter material
Dust retainingjDust retaining
capacity of s capacity of
0.5 x 0.5 m j 1 nr
in K i in fir
Dust retaining
capacity of
the filter
oabarit in K
Material layer
0.5 i 0.5 m
S - 0.25 m
a) Mineral wool, bitumen
treated; rate of air
passage 0.66 - 0.25
ra/sec 20
b) Ditto, rate of air
passage 0.9 x 0*3
a/secj weight of
layer 400 g 21.8
c) Four-layer-lignin,
rate of air passage
1.0 - 0.36 ra/sec 10
Material layer -
O.5 x 2.0 m
S = 1 m2
a) Mineral wool, bitumen
treated, rate of air
passage 1.0 * 0.4 ni/sec?
weight of layer 2.150 g 69
b) Ditto} rate of air
passage 0.5 - 0.35
m/secj weigrt of
layer 2,300 g
- c) Ditto plus one lignin
layer? rate of air
passage 1.0 - 0*5 m/seo 45.4
d) Six layers of lignin}
rate of air pass-age
1»0 - 0.4 m/seo 15
AH
80
87
40
69
45.5
45.4
15
80
87
40
276
182
181
60
-154-
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'. Arc welding generates dust of ferric and 'manganese oxides and'also gaseous
oxides of nitrogen and carbon. Testa of aix control samples for these gases
showed that daring reoiroulation of the air for I to 3 hours the content of
these gases in the air waei oxides of nitrogen 0.001$ - 0.004 o£/li» with an
average of 0*002 m^/lij carbon monoxide averaged 0.01 mg/H, i.e., below the
allowable concentrations.
Conclusions.
1. With an initial content of arc-welding dust of 10 mg/n of air the
efficiency of bitumen treated mineral wool as a dust remover was 80$, reaching
90£ and even higher in isolated cases. After filtering! the air dust content
did not exceed 1 mg/rn in a large majority of cases.
2. Filtering the air through a layer of mineral wool reduced its dust
content from 0.21 to 0.018 mg/oi , which. is approximately a removal of $1% of
the dust.
3. The content of oxides of nitrogen and of carbon monoxide in the re-
circulated air was below the limit of allowable concentration.
4« The use of mineral wool for the purification of air from arc-welding
2
aerosols proved practical only where the air load per 1 m of the filter-layer
did not exceed 450 "• 600 ™ /ncurj a greater load rendered the filter inopera-
tive within a short time. Beoirculation of air can be resorted to where in-
dividual reoiroulation ventilators (fans) can be installed at points of weldliu
the polluted air intakes can be installed close to the ceiling and the purifiei
air can be delivered directly to the working area*
The apparatus should be made up of individual filter cells and the minera.
wool overlaid in a wave-like or zigzag manner. In computing the rate of air r
circulation the residual dust content should be taken into account. The perfor
anoe of the ventilation units may be faulty at times; in addition to the dust,
the air may contain gases cooing from the arc welding; therefore, it is oug*-
gested that the air supplied to the shop during the cold seasons should be not
less than 3Q£ of the total unventilated air exchange, which amounts to 700 -
1,000 m /hour per 1 kg of burned electrodes*
2
5. In these experiments, the dust-retaining capacity of 1 m mineral fil-
ters averaged 200 g* With an initial air dust concentration of 5 mg/m and a
229 000
rate of air passing of 0.5 m/eec, a filter pad should last - ^ TftnQ ° 25 hours.
-155-
-------
or three working shifts* Where the Initial dust concentration ie greater than
5 mg/m , the time between filter changes should he shortened accordingly. •
6. Whether the use of mineral wool filter ie economically sound in any
particular arc-welding shop, should'he decided in each individual case* Such
air filters should be adequate for smaller shops with a moderate load of aro-
welding.
7. The use of mineral wool for the purification of recirculating air in
arc-welding shops may he more economical than the present fresh air method hy
4 to 8 times.
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'Electrostatic Apparatus for the Collection of Atmospheric^Dust Samples.
- i -. ~ ' '.
.By v» P. Litvinov and N. N. Litvinova.
From the Department of General Physics, Rostov University.
Gigiena i Sanitariya 1955> No. 9> P» 16.
In Gigiena i Sanitariya, 1950, No. 10, we described an electrostatic ap-
paratus with a dielectric electrode for the collection of atmospheric dust
samples. The air containing the suspended dust particles was aspirated through
a prismatic electrostatic aspiration condenser} the dust particles "became
charged and were forcefully propelled against flat glass plates 'attached to
the sides of the condenser. Generally one sample of dust collected from the
glass surface was sufficient for the performance of gravimetric, dispersion, .
mineralogical, luminescent, microchemical and other determinations.
Basic shortcomings of this model were: its weight, the need to'enclose
the transformer and the high voltage line as a measure of safety which inter-
fered with the freedom of the air current; its operation required a 100 w al-
ternating current which precluded it from use under certain field conditions. *
The apparatus was redesigned in 1952 - 53; the condenser, the anemometer and
'•*•)••
the aspirator were left unchanged; but the condenser "block was simplified,
reduced in weight and its aerodynamic properties improved, especially when
mounted on a ligjit stand. (Fig. l).
In designing the new electroprecipitator model provision was made for the
possible replacement of the cup-shaped condenser-anemometer "by a special flow
meter. (Fig. 2). The direct current of 6 - 8 v. and 1 - 2 mA (milliamperes)
required for the operation of the new electricfilter dust collector was con-
trolled by a special electric bulb arrangement. Electric precipitators used
in laboratories were operated by an alternating city current, and those used
in the field were operated "by special batteries.
The laboratory model feeding block is shown in Fig. 3. It consists of a
hi^i-frequency bulb-type generator assembled in a wooden box with a removable
cover. The box, measuring 375 * 245 *• 235 mm> nas a front panel en which are»
a kilo-voltmeter, a high-tension regulator handle, switches and terminals.
The voltage is increased by a special high-frequency transformer" and is rec-
tified by a bulb circuit. The generator is connected to the circuit by a plug;
the high voltage is regulated by a potentiometer by moving the handle on the
-157-
-------
front panel of the apparatus under the kilo-voltmeter which indicates the
voltage coming froia the "block.
The high voltage is supplied from the block to the condenser of the eleo-
tricfilter precipitator. Its negative pole is connected with the dielectric
electrode of the condenser and the positive is grounded. To protect the supply
"block from overloading, -.shich, may occur due to increased voltage in the circuit
or to a "break in the block load, for example, when the line "breaks, the appa-
ratus is provided with a fuse. Low and high voltage are turned on "by appro-
priate switches, mounted in the front panel of the apparatus. (Pig. 3).
Energy consumed by the electric dust collector ranged "between 60 - 70 w
for the corona (dielectric) electrode; it takea about 30 w to rotate the small
electromotor of the aspirator; the apparatus can be safely plugged into any
circuit. The current supply block of the field model was designed for opera-
tion hy a portable storage battery; otherwise it is constructed exactly the
same as the laboratory model. The 4 - 6 v, 30-40 A/hour battery is placed
inside the box. The low voltage current is fed from the battery through the
double-half period circuit breaker to the primary coil of the step-up.trans-
former. The tension from the high voltage coil is rectified (with a doub-
ling) through the. kenotron system and is then fed to the outgoing terminals
of the apparatus. Bnergy consumed is about 10 - 15 *.
In spite of a high-tension (6 - 8 kV), both supply blocks are safe, be-
cause contact with a low-power bulb circuit will merely disarrange the appa-
ratus} it may discontinue to generate high frequency, but without serious or
unpleasant consequences. Likewise, supercharging will merely blow the fuse,
but will cause no damage to the apparatus, -- -
The 1951 model weighed over 30 kg, the Ig5> laboratory model weighs
about 10 kg; the field model with the storage battery weighs about 15 kg.
The set-up, divided and packed into two boxes ^hich can easily be carried
by one person, stands transportation very well* The 1953 models are manufac-
tured in the experimental shops of the Rostov University (Director - A. D.
Guda). They were used in Rostov on/Don under field and laboratory conditions
to obtain samples of atmospheric and industrial dust in cooperation with the
Department of Labor Hygiene of the Rostov on/Don Medical Institute.
The efficiency of industrial dust-catching by the newly designed appa-
ratus was tested in the polishing shops of one of the industrial plants.
-158-
• e? • '
-------
Samples were taken simultaneously with field model and with Dr. D. I. Kagan's
cotton fiber filter. The results indicated that with dust concentrations up
to 10 mg/m both methods yielded satisfactory gravimetric results. However,
the electricfilter type yielded higher concentration values in the majority of
cases.
Simultaneously, air dust samples were collected with the V/enson particle
counter No. 1 to determine collected degree of dispersion. The fractional
dust composition was closely alike with one difference: dust particles ad-
hering to the"glass plates of the electric collector contained particles of
10 n and even 20 n in diameter which were not found in counter No. 1. Dust
particles of less than 1 u in diameter, as well as particles with diameter up
to 10 n settled very firmly on the surface of the electric precipitator glass
plates. They were not shaken off in transportation if glass was kept in a
vertical position in a specially designed holder box. In the case of the glass,
dust particles failed to come loose completely with water or alcohol from a
wash bottle: to obttiin a sample for chemical analysis it was necessary to use
a rubber policeman or a fine brush.
The 1953 electric precipitator models are convenient, simple, easily port-
able and can be used for the collection of dust samples of relatively low con-
centration. The development of practical and reliable methods for the analyses
of dust settled on the glass plates of the apparatus described is the present
primary task of our laboratory.
Experiments conducted in mines demonstrated that our apparatus was not
suitable fo^ the collection of dust san.ples from air with dust concentration
above. 30 - 50 mg/m . Attempts are now being made to develop special electric
dust sample collectors which will meet all conditions.
-159-
-------
•;: ;-:s
•
•- • -:
•
H
Fig. . 1. Electrof liter condenser block
p
*
' ,
Pig. 2. Condenser block and rheoineter
•
; ,Boi-enclosed feeding block
ia open ehowing outside panel.
-160-
-------
Method for the Collection of Samples of Air Dust with Particle Diameters
of Less Than 5 P*
27. I. Smetanin.
Tashkent Medical Institute*
Gigiena Truda i Professional'nye Zabolevaniya, Vol. 2, No. 2, 52-54, 1958.
Standard dust concentrations in the air of work places are prescribed by
the All-Union State Standard Sanitary Code G03F-H-101-54. The allowable con-
centration of dust is based on the quantity of free silicon dioxide contained
in it (from 2 to 10 mg/m ) regardless of the degree of dust dispersion* Ac-
cording to information found in the literature on this subject dust particles
of 1 - 5 n in diameter were most penetrating and most harmful to man* Ye. V,
demonstrated in 1956 that particles measuring 1 - 2 n produced fibre—
genie effects j this view was expressed by IFegelsbmidt, Nelson, King and Harrison
in 1955* Therefore, this author is of the opinion that in its practice the
sanitary inspector should determine the content of free silicon dioxide not only
graviiaetrically but also on the basis of fractional degree of 5 u °r less* In
fact, such has been the practice in experimental studies of dust pathology by
intratracheal administration to laboratory animals where the material has been
previously ground to any desired size or degree of dispersion. Such grinding
of polydispersed dust reduces large particles to smaller ones, breaks up ag-
glomerations thereby changing such physical properties of the dust as its gen-
eral structure, electric charges, etc. Grinding larger particles of mixed dust
with the smaller ones artificially changes the content of free silicon dioxide
ia the smaller dust particles. Therefore, under practical conditions it is de-
sirable to study the effect of dust in its naturally occurring state in differ-
ential fractions according to diameter sizes* This called for the development
of a sethod of dust separation into fractions according to diameters occurring
under actual working conditions. Fractions of naturally encountered dust, having
particle diameters of 5 u or less, are essential factors in the study of their
removal rate from the organiera, their toxioity. and the effect of total surface
or mechanical effect on the tissue, etc* It is important that investigators
have natural dust consisting of particles up to 5 P> and that the dusts be of a
more homogenous dispersion than dusts obtained from laboratory grinding. This
-161-
-------
-
is equally true of coaplex duate consisting of naturally highly dispersed frac-
tion**. To attain this a simple apparaittz has been developed for the separation
j
and collection of air pollution duet fractions baring particle diameters of 5 P
and less. The procedure is essentially one of fractional air dust centrifuga-
tion.
The apparatus. The principal part of the apparatus consists of a machine-
ground brass or galvanised tin box of 110 nm in diameter and 25 mm deep (Fig*
1-2). It has a cover of corresponding siee. The thickness of the box walls
are 1.5 a*n. An axle in the center of the box extends high enough through a
•
hole in the middle of the lid. The lid is rubber-lined, and when in place is
fastened firmly and tightly over the round box with a nut; when the cover is
fastened over the apparatus the box is hermetically sealed. The ends of the
axle are hollowed cut. The lower end of the axle serves as an adapter by means
of which the round box is placed over the axle of a vertically mounted electric
-
motor.
Fig. 2
Fig
Th.e upper part of the axle (i>) has a base 5 M» i*1 diameter which connects
with the inside of the apparatus hj a slit (K) in the aria. A spiral partition
(C) is soldered to the bottom of the box; it is of uneven diameter and where it
changes frcm the larger to the smaller diameter it forma an angle (B). Five
small partitions extend from the axle as radii 1, 2, 3, 4 and 5l one of them
(3) extends to the spiral wall, the others end 10 mm from the spiral wall (C).
At the top part of the solid partitions, near the axle, a 5 z 10 am opening is
made; its longer side extends from the axle radially. In the box, at the end
of the spiral (C), there is a 5 x 8 urn opening through which the inside of the
-162-
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box cossBunieates with the outside air* It is protected with a conical tin
ahidld (3h).
Procedure of work with the apparatus. Before setting the centrifugal air
separator into operation a cellulose film 42 cm long and 22 cm vide is fitted
into the apparatus. The strip thus takes on a spiral form from the indentation
(3) to opening (V) identical with the shape of the spiral partition (C) and the
outer wall of the apparatus* The cover is put on and tightened by screwing the
nut onto the axle. The apparatus is then adjusted over the vertical axis of
the electric motor separated from the apparatus by a protective sheath of gal-
vanized tin corresponding in siae to that of the apparatus.
The motor rotation sets the apparatus into motion clockwise at a speed of
1400 rpm. The centrifugal force developed within the apparatus forces out the
air from the inside through opening (V), creating a partial vacuum inside the
apparatus, which in turn sucks in the dust-polluted .outside air at a definite
speed. The outside air enters through, opening (D) at the top of the axle and
enters the retaining box through slit (£}, which is 5 x 8 mm. As the result of
the air revolving inside the apparatus and of the developed centriTugal force,
large dust particles suspended in the air begin to separate in differential
zone (A). At this point smaller dust particles do not separate but are carried
with the air current through opening (C) in partition (3). The next air move-
ment encounters indentation (B) which throws the finer dust particles against
the celluloid strip, to which they adhere, down to outlet (0). Bust particles
of 5 H &nd smaller are deposited where tho celluloid strip starts; 3 p and less
are deposited on the mid-part and 1 - 2 (i and less are deposited at the last
section of the celluloid strip. Disintegration of dust is obviated because it
is deposited on the strip in layers. Dust particles of 7 P and less collect at
point E on the section of tha inserted celluloid strip. The rato of dust a©-
cumulatiosL on the celluloid strip depends upon its concentration in the air.
Five minutes after tho apparatus has boea sot in motion the lid can be tc&oa. of£
and th@ strip removed for examination under tha microscope to determine the sise
and distribution of the dust particles. This is done best by first cutting the
strip into sections and appropriately pvtrTdng them.
The apparatus should be run until a sufficient quantity of fine dust has
accumulated on the strip from indentation (B) to the end of the strip. Uesaally
from 10 - 15 Eg of dnst collects on tha strip. The rate of accumulation of large
diameter dust partioleu at point (A) will determine the time when a n@w celluloid
-163-
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strip is to be inserted after section (A) of the apparatus has been thoroughly
freed of dust. It was feared that as a result of vibration the dust mi£rt shako
off the celluloid strip. Experiments demonstrated that this did not occur in
the ease of highly dispersed dust particles; in the case of particles of larger
diameters* special means had to be used to retain the particles on the strip.
ffhe dust was lifted off the strip with a Email piece of celluloid or X-ray fila
by pushing the dust away frca oneself and placing the strip on a piece of black
paper. It is expedient to have several celluloid strips for continuous opera-
4ioni while a collection is in the process, the laboratory worker can remove
the dust from the used ribbon in a clean, dust-free room. Shaking of the dust-
covered stripe when carrying them had no effect on them} nevertheless, special
strip holders should be used if the strips are to be transported over long dis-
tances* Strips should be cut into 2 or 3 sections before placing thea in the
holders.
The author has made extensive use of the described apparatus for the sepa-
ration from surface dust of highly dispersed particles directly in the labora-
tory. Dust deposited in the process of manufacturing was collected on plywood
then screened through a sieve of 40 p mesh. Fifty g of the sifted dust was
placed into a tightly woven cloth bag which was then vigorously shaken over the
revolving apparatus for 3-5 min. The desired fraction of dust was collected
from the celluloid strip. In this way it was possible to obtain a quantity of
highly dispersed dust required for laboratory and experimental study.
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Aspirators for Sampling Atmospheric Air Dost and Oases.
I*. P. Kachor.
The Erieman Central Solenttfio Research Institute*
Gigiena i Sanitariya, Ho. 4, 43-51, 1938.
Aspiration apparatus used in collecting atmospheric air samples can be
grouped intot 1) those which require outside sources of energy, and 2) those
which use energy generated by components installed directly in the aspiration
apparatus. Fixed-point atmospheric air investigations over long periods of
time are usually carried out "by aspiration apparatus of the first type* Appa-
ratus of the second type can be used in non-fixed point investigations and under
special field conditions, which the aspiration apparatus must meet adequately.
In collecting air samples at points considerably removed from the source of pol-
lution, where air dust concentrations say be low, large volumes of atmospheric
air must be aspirated through the apparatus* Under conditions of frequent changes
in wind direction the sample must be collected quickly, or the sampling point
may have to be changed. This can be done only when the apparatus is easily
mobile and can be quickly set into operation without disturbing its operating
precision. Apparatus presently used in field work for determining air-dust '
concentration, such as water-operated aspirators, portable vacuum puspe. elee-
trieally-oper&ted aspirators, etc., do not fully meet the above requirements.
Therefore, this author constructed a new type of portable apparatus for col-
lecting air samples which is operated by direct suction froa an autcmobilo car-
bureto?. In this connection the following had to be taken into considerations
the automobile-operated aspirator had to work continuously creating adequate
suction during "idle strokes*1 of the engine) the aspirator had to be constructed
sc that it could be attached to the motor without having to make any change In
the latter} it should be possible to attach, the ssw aspirator to any type of
autc&obilo having a minimum of 4 cylinders and an air passage rate not exceeding
1.5 E/BOO,. Too types of automobile aspirators wore prepared. The first type
consisted of an iron elbow pipe with a diaphre$a soldered into it} an adapter
Candidate of Bed. Sciences B. H, Gorlaov and Candidates of Teoh. Sciences
H. F. Dergaeher and H. P. Kalinuahkia participated in this work*
-165-
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for ft manometer, a coupling for the attachment of the aspirator to the carbure-
tor, a bushing for the insertion of the metallic adapters, a headpiece or shield
H
to equalize the rate of air suction with the velocity of the wind, and a required
number of metallic adapters. The aspirator had to be connected with the carbu-
retor of the engine rigidly tgr means of an appropriate coupling. The automobile
aspirator, as it appears in operation is shown in Tig. 1.
The second type of automobile as-
pirator (Fig. 2} is connected to the
carburetor by a rubber hose and can be
used with any type of internal combus-
tion aute engine. This aspirator con-
sists of a T-shaped tube (l), at one
of its wide ends a bushing (2) is at-
tached for ft Ttng metallic adapters and
headpieces; at the other end there is
a baffle plate (3), to the narrow con-
necting pipe (4) a rubber hose is at-
Pig. 1.
Pig. 2. Automobile aspirator of
Qoooud type
- T-shaped pipe; 2 - bushing for fastening of
metallic adapters; 3 - throttle valve; 4 - con-
necting end (narrow); 5 - rubber hose; 6 -
duoing bush.
tached (5) with a coupling for joining
*
the aspirator to the car-
buretor. The metallic
filter adapter (Fig. 3)
consists of a Duralumi-
n»B cylinder (1), a thrust
collar (2), a supporting
screen (3) and a circular
spring for packing the
cotton filter (4)*
During transporta-
tion, the metallie fil-
ter adapters are covered
with caps. The weight
of the adapters without
•
the caps varies between
14 and 1? g and is prac-
tically equal to that of
-166-
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Fig. 3. Metallic adapter
glass adapters. The pressure drop of a metallic
filter adapter with a layer of mineral cotton
weighing 3 g does not exceed 40 urn of water at
an aspiration speed of 100 li/minj toward the
end of the experiment, the pressure drop in*
creases to 80 - 100 mm. Checking of the metal-
lic adapter* showed that with the cotton packing
weighing 3 g, leas than l£ of the dust passed
through the filter, a quantity regarded as neg-
ligible* The suction capacity of an automobile
aspirator can be determined by the formula
Q e A P, where Q is suction capacity in li/min;
F is the pressure drop registered by the mano-
1 - Buraluminum cylinder?
2 - thrust collar* 3 - sup-
porting screens 4 - ring-
shaped compression spring;
5 — miner&l wool
meter in mm of water, and A is a constant determined in calibrating or stand-
ardizing the automobile aspirator. An aspirator should be equipped with sev-
eral headpieces of different diameters. Depending upon the wind velocity, a
headpiece of a suitabla
diameter is selected
using the nomograph pre-
sented in Fig. 4. To
facilitate calculations,
a curve representing the
aspirator capacity in
relation to the pressure
u-rop of the manometer is
given in the same diagram.
The operating pro-
cedure of the automobile
aspirator is aa follows:
the aspirator is con-
nected to the carburetor;
the force of the wind is
measured using an anemom-
eter; the diameter re-
quired for the shield is
of
too
/to
tso
t*0
riff
tea
00
to
40
fO
tO IS tO tS
P in mm of water column
to
7 in/sec*
Fig. 4. Graph of working rates in the adapter, of
filtration suction rates at fittings and of the
automobile aspirator efficiency
-------
:
determined from the diagraa; the desired pressure drop of the manometer is ob-
-
tained by regulating the baffle plate of the carburetor or of the aspirator,
and the adapter with the adjusted shield is then inserted! the air sample can
then be collected. When the sampling is completed the metallic adapter is re-
4
moved and capped by two covers; in this way it is transported to the weighing
place* ' '
Automobile aspirators of the described construction have been checked in
F •
practical work and found to be satisfactory; their wide use in determining air
dust concentration in field work is recommended. The automobile aspirator has
been used in determining gaseous air pollutants such as SO. and was found to be
*
somewhat wanting. For such purposes a special "field aspirator" of the accumu-
-
later type was assembled (Pig* 5).
All naeded parts and the source of
energy required for the field aspirator
were mounted in one case measuring 250
z 200 mm at the base and 300 mm in
height* The case opens in the front
and back. A special type of fan at-
tached to the rear end of the motor
Fig. 5* Field apparatus open to view
shaft and the carrying back was equipped
with a direct current motor accumulator*
. A Schott absorber with a fine-pore disk,
A flowmeter, an electric generator regu-
lator and 8 test tubes with the neces-
sary reagents are mounted in the front part of the case. The entire installa-
tion weighs 8 kg. The suction capacity of this type of aspirator with a Schott
absorber had a maTrlmtim of 7 li/min. Fully charged accumulators were good for
5 hours. It is suggested that an additional accumulator be included in case of
•
emergency.
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Adaptation of the Tu. A. Krotov Apparatus to Bacteriological Studies of
Atmospheric Air Under Field Conditions.
H. H. Poterovskii, Ta. G. Kishko and A. P. Ostranitsa.
From L'vov Institute of Epidemiology, Microbiology and Hy
Lab. Delo, Vol. 4, Ho. 2, 45-4*, 1958.
Tu. A. Krotov1 3 apparatus for bacteriological investigation of the air,
manufactured by the domestic medical industry operates on an alternating cur-
rent of 127 V; for this reason it cannot be used in field investigations of
atmospheric air. Other devices, such as the Shafir air centrifuge, Wells,
Burdillon, etc., which are widely used in the U.S.S.R. and abroad, have the
same serious shortcomings. The operation of such apparatus in the field re-
quires the installation of outlets on electric poles, buildings, etc., which
are costly and even at best do not render air sampling possible in many in-
habited areas.
During the investigation of the atmospheric air in 1955 these investigators
introduced the following modifications into the original Krotov apparatus: the
alternating current motor was replaced by a transformer with an incoming current
of 12 V, an outgoing current of 120 V and equipped with a changeover coil switch.
The axle of the converter was extended for the attachment of a small pressure
blower* The following Figure is a schematic drawing of the transformer connec-
tion with the coil changeover switch.
In the .lower part of the apparatus housing
loooooooo/l ^tto, there is an opening through which the trans-
M
*' former can be connected with the alternating
000000001 I or with tllQ
-------
Two years' experience with the modified apparatus shoved that the results
of the investigations were independent of the type of the current used, whether
direct or alternating, as well as of the voltage, such as 6 to 12, 12? or 220
volts) but the rate and direction of air aspiration were factors of paramount
importance.
In reply to a request a new improved model of the Krotov apparatus was ex-
hibited at the IV All-Union Conference on Problems of Sanitary Bacteriology*
April 1957; the overall size of the apparatus was reduced to half the size of
the former model; it was equipped with a manometer and was designed for use
with alternating current only.
It is recommended that the improvements herein described be incorporated
in all Krotov apparatus to be manufactured hereafter*
Old models of Krotov apparatus found in laboratories can be easily con-
verted into the improved type.
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Atmospheric Air Pollution with Sulfur Dioxide from Mining Rook Pumps*
*
D. H. Kalyuahnyi, S. A* Davydov, L. G. Dukarskaya and 11. B. Aksel*rod»
Proa the Ukrainian Institute of Communal Hygiene.
Gigiena i Sanitariya, Ho. 5, 19-24, 1950.
Coal mining necessitates dumping of waste rock which has the property of
spontaneous combustion accompanied by the liberation of sulfur dioxide into the
air. The Ukrainian Institute of Community Hygiene made a study of air pollution
oy sulfur dioxide in an area close to coal mines with a view to instituting a
scientifically organized sanitary clearance zone (green belt) between the waste
rock dumps and residences, suitable to conditions prevailing in the Donets coal
basin* The mined coal is enriched in concentration plants by cashing it, fol-
lowed by hand sorting. Coal screening is done directly in the mines} the waste
rook is brought up from the pits and dumped into pyramidal heaps reaching 80 -
100 m in height. Inevitably some coal and iron pyrite get into the waste rock
dumps. Depending upon the composition of the coal and the character of the bed
rock and of the strata overlaying the coal vein, the following can be found in
a pyramidal rook-dumps l) clay shale consisting of aluminum silicate, iron,
calcium and magnesium; 2) aand shale* 3) coal shale consisting of rock inter-
mingled with carbonaceous matter; 4) iron pyritess and 5) coal.
The organic components of mined coal consist of carbon, hydrogen, oxygen,
nitrogen and sulfur.. In addition, coal contains inorganic carter in the form
of pyrites, marcasite and sulfatos. The total content of sulfur in Donets coal
varies from 0.5 to 5£* It is also necessary to point out that the same vein
may be of different qualities; this has a considerable effect on the combustion
intensity of waste rock coming from different mining stages* Spontaneous com-
bustion of coal, or of rock containing coal, is due to the fact that the surface
of coal absorbs molecular oxygen from the air, forming an unstable peroxide
compound. The latter roadily decomposes and liberates nascent oxygen which
oxidizes the coal to a stable oxygon-rich compound. In this process heat is
produced which hastens the oxidation, culminating in spontaneous combustion*
Increased coal combustion observed after raina, particularly when accompanied
by thunderstorms, can be explained as due to the wetting of coal with water
containing diluted ozone* Sulfur dioxide is produced from the combustion of
-171-
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organic sulfur and of pyrite.
Rock combustion smoke emanating' from the surface of waste dumps can be
seen during daylight; the smoke intensity varies with the rate of combustion
and the degree of dispersion of liberated aerosol; at night, a violet glow can
be aeen, and at times even tongues of flame. The investigations here reported
on were carried out in 1948 in 3 mines of the Stalin region and in two mines of
the Voroshilov region; the intensity of waste dump combustion in these regions
differed greatly. Samples of air were collected on the lee side at a distance
of 2 km using portable aspirators connected to three successive Petri absorbers,
each absorber .ohtaining 10 ml of absorber solution (52 Berthollet's salt so-
lution). From 100 to 500 li of ai? were aspirated at a rate of 40 - 50 li per
hour. Analysis was made nephelometrically. The results of laboratory investi-
gations made in the summer of 1946 are plotted in the form of curves in Fige.
1, 2 and 3. The total number cf analyses was 82. The greatest air pollution
with sulfur dioxide near rock dumps of 5 investigate! mines was found in the
two mines of the Voroshilovgrad region (from 2.21 to 11.1 mg/m ). This may
have been due to the presence of sulfur pyrite in waste piles whioh rapidly
oxidizes in the air to sulfur dioxide* Lower waste piles in these mines created
a higher concentration of sulfur dioxide in the air of the proximity. Libera-
tion of sulfur dioxide to a lesser extent was found in the F. Eon mine of the
Stalin region, where the mftTHiPimi concentration of gas olose to the rook dumps
was 3*48 mg/m and minimum
0.91 mg/m . The air olose
to the rook dumps of the
other two mines was not in-
vestigated.
The diffusion of sulfur
dioxide from its original
source followed a pattern
characteristic to all mines:
the concentration gradually
decreased with the distance
from the mines. At a dis-
tance of 100 a from the rook
dump the mini mum concentra-
"l
10
a
to '
2
*
IP
J
•H 4
C^J
n
. .*
f
0
//./
1
\
\
A " b~Y indexes
\ -Hax. indexes
\ Ittn,' indexes
\
\
>
\ \
\ \
\ \
\ ^ " IOJ 0*6
\ *~~~~~ '*••—. ^^0*6 / 027 ' ~ 022
f£^ \ 052 ^~Q07~~~ — ~~^/,°Ji /^ OIS
"~fc"""'-~-. pflff "" ~ 111 ^?=^n iifimii,™****'0**
500
Distance from the mine in m«
Fig. 1
-172-
-------
It
a
s
^'
!n 7
Pi '
IP'
5 >
CJ
O *
Av. indexes
Hax, indexes
Pi
CO
?^
Jt« A w«
^ •"*• ™ " •
V\
V
\*-^ H«J i*»
Vr^T A°"
\09
-^
\0»
=4oag
oo
/> *w ^ffff XQ sea no
Distance from the mine in m.
2SO SOS 7M IOOQ
Distance from the mine in m.
Fig. 3.
tion of sulfur dioxide was 0.31 and the max-
imum 1.7 o£/B ; at 300 m from the =dne the
maxl*maro concentration dropped to 50$ as
compared with that of the preceding point
(0.83 rng/m )| at 500 m, in one mine, the
^
concentration of 30. was 1.35 - 1*8
Pig. 2.
in the other mines the mnri mum concentra-
tions varied from 0.20 to 0.66 mg/m ; the
average concentration of the entire study was 0.52 mg/m . At 1,000 m the con-
centration of sulfur dioxide varied from 0.07 to 1.07 mg/m , and at 1,500 m
from 0.15 to 0.46 mg/m . In the "lidievka" mine, sulfur dioxide was percepti-
ble even at 2 km from the rook dump. The stronger concentration of sulfur di-
oxide at "2-7 Lidievka" mine may have been due to a more intensive combustion
of waste rock and also to rainfall prevailing during our investigations! rahioh
supported the hypothesis previously expressed that when rock dumps.became wet,
oxidation occurred more intensely; this in turn lead to increased liberation
of sulfur dioxide into the air. The village residents frequently felt the odor
of sulfur dioxide in warm or rainy weather*
The question posed by the above results vast How to evaluate the concentra-
tions of sulfur dioxide observed from the hygienic point of view and at what
distances from the source of liberation- can S02 produce noxious.effects on the
health of nearby residents? At the tim® of this investigation no legal stan-
dards have been in force for the maximum concentration of sulfur dioxide in at-
mospheric air; under such conditions the data obtained were evaluated on the
basis of suggestions of different authors in the light of the sanitary, technical
and natural conditions prevailing in the vicinities of the mine dumps investi-
-173-
-------
O
3
4*
0)
3o
C IQ
S ***
H C
O
o
•d «d
•H o
ss
m
g
oJ
t4
O
o
c
o
o
s
o
^
SI
*S'_
Si
O!
£i
Q}''
|l
S!
mi
Si-
•6AY
•xeft
i-
«
Q>
s
'*§•'
I".-.
00
oooo
*
o
>o
o
-.°.'.
o — o
OOO
eo —i
— i/:
-------
beape the S02 concentration in the air fell to the level of allowable limit at
500 - 750 a from the rook piles*
Studies of plant life of the Donets coal field showed that trees were se-
verely injured in the immediate proximity of the rock dumpsj 200 - 300 m away
injuries were slight. Beyond the limits of thia zone tree foliage appeared
normal* Information gathered by the question method showed that the odor of
SO- was felt at 300 0 from the dump leeward. Farther away and with a wind
velocity of 1.4 - 3*7 a/sec prevailing during our investigations, the odor of
sulfUr dioxide was not perceptible* In the case of coal mines and waste rock
dumps S0_ recovery by suitable installations is impractical and uneconomical.
It is recommended that the elimination of air pollution by sulfur dioxide
liberated from rock dumps be along the following lines! a) changing methods
of operation of underground coal mines by introducing underground gasification
and filling empty coal veins with waste rock; b) preventing spontaneous com-
bustion of waste rock and timely extinguishing of burning rock dumps; c) in-
stituting sanitary clearance zones between rock dumps and residential areas.
The moat appropriate methods which can obviate the piling of waste rock are
underground gasification and filling in emptied coal veins* The latter method -
"butovka" - could radically change.the location of workers* villages in the
Donets coal field. The Ministry of the Coal Industry should energetically en-
force the practice of "butovka"* Methods for the prevention of spontaneous
combustion and for extinguishing burning waste rock dumps are still in the ex-
perimental stage* Attempts to extinguish burning rock waste dumps with lime did
not produce the desired results. However, the idea aa such merits attention
and should be studied further*
The State Institute for City Planning proposed that waste rock be used for
filling ravines so numerous in the Donets coal field* The haulage of waste
rock by rail to a nearest ravine instead of a rock dump should present no dif-
ficulties and would serve to prevent the formation of rock dumps which are the
sore spots of sanitary and architectural planning*
In mines where the measures mentioned are not in use the State Sanitary
Inspection organizations oust enforce sanitary clearance zones, which proved
effective in reducing or eliminating the noxious effect of burning waste dumps*
An analysis of the data of investigations made in 1943 and a comparison with
those of 1937 leads to the conclusion that sanitary clearance zones in the
-175-
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Donets coal mine region should be 500 to 1000 m vide. In mine regions having
intensive spontaneous combustion in rock dumps, sanitary clearance zone should
be 750 - 1000 m vide and on the windward Bide 500 m vide. The above should be
applied also to new mines the coal and waste rock of which may contain favorable
pox-cent of sulfur* compounds.
Summary,
1. Emission of sulfur dioxide into the air was caused by the oxidation
of sulfur compounds present in dumped coal and waste rook*
2. The intensity of waste rock burning in rock dumps and the quantity of
sulfur dioxida liberated depended upon the chemical composition of the coal
and tiie waste rock, the height of rock dumps, the duration of their accumula-
tion, meteorological conditions, etc,
3. In mines with an intensive burning of waste rock and with high rock
dumps increased concentrations of sulfur dioxide were found up to 1500 a from
the source. In mines with low and slow burning dumps, diffusion of sulfur di-
oxide did not extend beyond 750 m.
4* Sanitary clearance zones between rock dumps and residential quarters
should be 500 - 1300 m wide, depending on the intensity of dumps1 burning, the
direction of prevailing winds, and the chemical composition of the coal and of
the waste-rock.
5. ?he method of filling in emptied coal veins, or "butovka", should be
put into wide practice in coal mining by organizations concerned with this
problem. This should eliminate further dunp heap accumulations. Waste rock
should also be used for filling in of ravines. Extinguished dumps should be
planted with appropriate shrubs and trees.
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The Purification of Air Polluted by Vapors and Oases.
By V. G. Katsak.
From the Central Sanitary and Hygienic laboratory of Moscow.
Gigiena i Sanitariya, Ho. 8, 1950, pp. 2O-2J.
In the face of the rapid growth of towns and of the country's industries
the problem of atmospheric air protection from industrial vapor and gas emis-
sions became an acute one. Sanitary clearance zones of 2 km create worker's
transportation difficulties and do not always achieve the desired results; at
best, they reprerent a passive means of atmospheric air protection in residen-
tial areas of towns and industrial centers. The law concerning the protection
of atmospheric air must require more positive and direct methods of com-
batting industrial waste emissions such as purification and recovery prior to
emission, etc.
Noxious substances ejected by installations, such as gas exhausts, as a
rule, are characterized by high concentration in comparatively small volumes
of air-gas mixtures. This makes the recovery of air polluting substances from
exhaust gases economical. Methods for the recovery of such air pollutants have
been well studied in most cases; it was found easier to purify exhaust gases
than ventilation air. The content of gas impurities in the latter is of a com-
paratively low concentration, although from the viewpoint of sanitation and hy-
giene it may exceed the permissible safety limit. The volume of air emitted
by ventilating installations is large and the pollutant concentration compara-
tively low, two factors which make purification of air and pollutant recovery
costly and technically complicated.
From the viewpoint of economy and hygiene it is important to recover and
purify gases. The removal of acid gases such as sulfur dioxide, hydrogen chlo-
ride, nitric acid, etc. from industrially emitted gases and ventilation air aids
in the preservation of plant life, roofs of buildings, metallic ornamentation,
such as statues and monuments in the vicinity of industrial plants, etc. Most
important is the fact that the air purity in the factory and its surrounding
residential area can be kept within safe sanitary-hygienic levels. Ventilation
sir can be purified close to 100? and returned to the industrial building, thus
saving fuel during the winter months. Generally, the solution of this problem
depends essentially on the concentration of polluting gases and vapors contained
-177-
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in the industrial emissions.
1. Chemical purification method. Gases are more completely caught by-
chemical purifiers which convert them into relatively harmless and non-volatile
substances. Thus acid reacting hydrogen sulfide, sulfur dioxide, nitric oxide,
hydrogen chloride and hydrogen fluoride,.passing through alkaline solutions, for*
salts usually soluble in water. Ammonia, which is alkaline, is completely
caught by eulfuric acid. In many instances it ia possible to recover 100$ of
the air polluting gases. For instance, by passing hydrogen sulfide and sulfur
dioxide through a solution containing 1 - 1.5£ excess of free alkali it is pos-
sible to completely free the air from these gases. Vapors of sulfuric acid and
of sulfuroua anhydride in the presence of air moisture form stable aerosols which
resist purification by the neutralization method.
Chemical purification of gasea l^y neutralization is usually done in scrub-
bers of different designs, all containing a liquid gas absorber (Pig. l). !fhe
- neutralization method is moat frequently used for
i
recovering exhaust gases coming from plant machin-
ery. In plants manufacturing nitric acid by the
tower condensation method tiie tail gases containing
uncondenaed nitric oxide are passed through alkali
towers which operate at an absorption efficiency
of 80 - 90i. The formed aerosol and oxide of ni-
' h
trogen, not fully- oxidized to HOg are not retained
by the alkaline solution.
In plants producing sulfuric acid by the con-
tact method alkali towers effectively absorb un-
oxidized sulfurous anhydride, converting it to
commercially valuable sodium sulfite. Chlorine
can also be recovered fully by alkaline solutions
IH (T) M * o-« an^> ^ hyposulfite. Hydrogen sulfide liberated in
coke, gravel, chorded pack- the production of sulfur dyes in aniline plants i&
iiig, etc.j 5 - spent fluid effectively absorbed V *&« alkali in scrubbers
6 — purifying flu— ^* *
equipped with mixers. Bhen hydrogen sulfide i» ab-
Fig. 1. A typical gas and
vapor scrubber
. Polluted airj 2 - puri-
outflow*
ld| 7 - spray device
sorbed, a solution of sodium sulfide la obtained,
which can be used aa raw material in the production of sulfur dyes.
Uoat above described methoda aid in the recovery of relatively valuable
-178-
-------
salts such as sulfites, nitrites and nitrates, eulfides and hydrosulfides, by-
poohlorates, etc* Unfortunately a wider use of this type of air purification
is prevented "by the lack of available reagent8, in particular, of alkalies and
acids. For this reason the majority of plants using the contact process for
the manufacturing of sulfuric acid have no alkali towers; and where such towers
exist the operation is frequently interrupted because of alkali shortage.
2. Condensation method. This method can be applied only to gases and va-
pors liberated in pure state and free from oil* In one of the phenol factories
benzosulphonic acid is neutralized with sodium sulfite, liberating almost purs
sulfur dioxide which can be used consnercially after drying and compressing at
4 atmospheres and cooled to +20 , which converts the gas to liquid; it is then
collected Into tanks or cisterns* If the vapor or gas contain air, then the
condensation has to be done under greater pressure and at lower temperature,
which makes recovery more costly. For this reason, the condensation method can-
not be applied to all waste recovery, since the tail gases usually contain air
in amounts surpassing the volume of the pollutant. This method is even less
suited for purifying ventilation air since it would require considerable com-
pression and cooling energy for condensation.
3* Liquid absorption method. This method is widely used in industry. Hy-
drochloric and nitric acids are prepared by passing hydrogen chloride vapors
through water. In using the absorption method for the recovery of gases from
gas-air mixtures it is necessary to boar in miad that this method is effective
only when the gas and vapor tension over the absorbing medium, i.e., their con-
centrations* are low as compared with the concentration in. solution* Under such
conditions the solution of hydrochloric and nitric acids can liberate hydrogen
chloride and nitric acid into the air; at the same time, their vapor tension, and
consequently their concentration in the air which is in contact with the liquid
phase, is considerably lower than in the liquid phase, Curves in Figs. 2 and 3.
illustrate changes in vapor tension over different concentrations of their acids.
The concavity at the base of the curves points to their negative characteristics.
Curves of the vapor tension of alcohol and of ether in creosol are of similar
type* (Fig. 2, 3 and 4.) The tension curve of HC1 vapor over hydrochloric acid
shows that HC1 containing air can be aspirated through 10£ HC1 solution and come
out with, as low a concentration as 0.008 mg/1- which la below the limit of al-
lowable HC1 concentration in air. This becomes more complicated in instances
when the air-gas mixture contains HC1 aerosol, because it is difficult to fully
-------
O Z / 68 10 IZ M J8 ti 20
% of HC1 in liiuTd'phase
2. HC1 vapor tension
over. different concentra-
tions of its liquid phase.
precipitate HC1 aerosol by washing; in the
absence of HC1 aerosol the absorption of
HC1 vapor by water is highly effective;
therefore, this method is used in many chem-
ical plants. Suppose that the air-gas mix-
ture contained about 5 ug/1 of nitric acid
which corresponds approximately to the con-
centration of HO and HUCL in tail gases es-
caping from the tower in the manufacture of
sulfuric acid; nitric acid vapor contained
in the exhaust air from nitrating centri-
fuges in the manufacture of smokeless pow-
der approaches the amount given above.
The curve representing tension of ni-
tric acid vapor over liquid nitric acid of
different concentrations (Fig* 3) shows that
passing the air—gas mixture through 3Q£ ni-
tric acid at a temperature of 20 brought
about a condensation of the greater part
of the nitric acid vapor. The concentration
of nitric acid vapor in air decreased from
5. mg/1 to 0.12 mg/1 which is an absorption
equal tos
(5 - 0;12) x 100
5
97*.
Here, as previously described, any formed aerosol will escape from the ab-
sorber to some extent. In addition, low nitric oxide (HO), which may be present
in the air-gas mixture, will aloo pass through the absorber apparatus* This au-
thor conducted experimental tests on the absorption of nitric oxides and of ni-
tric acid vapor in a plant manufacturing pyroxilinj the plant was equipped with
an air purifying apparatus of 1000 m /hour* Under the prevailing conditions.it
was possible to obtain 80 - 9056 absorption of nitric oxide end nitric acid vapor
I-'
contained in the air drawn from a nitrating centrifuge. In the case of sub-
stances with high vapor tension over the absorber surface, such as SCU or BH^
in water, the efficiency of recovery from air will be low. Thus, in aspirating
air containing 1% of S02 through water at 20° it is not possible to attain
-180-
-------
an S0_ tension lower than 60 uua, which corresponds
to 115 mfi/1 of SO. in the air. Again, suppose
that water is used to absorb ammonia from the air
in concentrations of 1 mg/1. As can be seen from
the curve of NH* tension over its solution in wa-
ter (Fig. 6) at a temperature of 20 , ammonia so-
lution in less than 10£ has a vapor tension
equivalent to 1 mg/1 concentration in air, which
is the equilibrium point of its water solution.
Thie shows that large quantities of water will be
required for the air purification. Final calcu-
lation demonstrating the technical impossibility
to absorb, ammonia from air by water was presented
for the benefit of those who, from time to time,
recoamend this method of ammonia removal from air.
. •*•_,__
H!K>3 in liquid phase Such MCOnmQndations were made at a plant of hard
Fig. 3. HH02 vapor'tension ( ' _ 6) Qn the other hand, solu-
over different concentra-
tions of its liquid phase. tions of alcohol and of ether in cresol and in
tetraline havo negative vapor tension curves.
Therefore, it was possible to recover °££ cf alcohol and of ether from the air-
vapor mixtures in pyroxilin manufacturing plants by using the cresol and tetra-
line solutions (Fig. ?)• These installations are still popular in the face of
competition from installations using hard absorbers such as activated coke. It
should be noted, however, that it is im-
possible to render air 100£ pure by the
absorption method* It produces good re-
sults in absorbing hydrogen chloride, hy-
drogen fluoride and nitric acid, and does
not require alkalies and acids. Low con-
centration acids obtained through, absorp-
tion can be used technically. The absorp-
o a a so to x so TO so ao~iQ9% tion 09thod can be applied to the purifi-
of ethylol or of ethyl
ether in the fluid cation of exhaust gases and ventilation
4/*Tapbr tension of eth^l air cominS from nitrating centrifugal ma-
alcohol and of ether in solu- chines in the manufacture of pyrozilin,
tions of oresol
-181-
-------
» m to saw
SO* content in water
Fig. 5« SOg vapor tension
over Its aqueous solution
The preceding is a discussion of only a few of the absorption methods used*
A great variety of absorbents and many methods of absorption have been pro-
posed for recovery of solvent vapors and of gaseous pollutants, many of which
hold considerable promise*
4» Absorption by solid absorbents (adaorpr
tion). This method is predominantly used in re-
covering vapors of many volatile organic solvents
such as alcohol, ethers, esters, aldehydes, ke-
tones, benzene, gasoline, etc* Hitric oxide, va-
pors of toxic agents, water vapors and a number
of other vapors and gases can also be recovered
by the method of adsorption. The method is not
applicable to the recovery of carbon monoxide,
carbon dioxide, hydrogen sulfide and sulfur con-*
talning organic compounds* Sulfur compounds are
generally decomposed by steam in activated char-
coal with the liberation of elementary sulfur. Sulfur retained in the capilla-
ries of the adsorber cannot be removed by steam rendering and the adsorbent be-
comes inactive. Adsorption possesses the
advantage of simultaneously adsorbing sev-
eral organic solvents, such as acetone va-
pors, acetates and benzene which are liber-
ated in the production of nitrous varnishes.
Activated charcoal and silicagel are
- used at present as the principal adsorbents*
The recovering capacity of these agents grows
rapidly with the increase in vapor concen-
. tration in the air up to a degree, after which
it remains constant regardless of th3 con-
centration. This phenomenon is illustrated
by a benaol-activated-charcoal adsorption
isotherm presented in Fig. 8. This type of
adsorption system can recover about 0.18 g
of benzene per 1 cm of charcoal. It should
be noted that the air-vapor mixture is com-
HEL content in water
Fig. 6. HB\ vapor tension
over different concentra-
tions of its liquid phase".
-182-
-------
pletely Unrated from the volatile solvents contained in it upon passing
through a layer of activated charcoal several sis thick. The adsorber layer
is usually 0.5 " 1*0 cm thick; this prevents the by-passing of the solvent
and the apparatus can operate for a considerable time before the adsorbent be-
comes saturated, fig. 9 is a schematic illustration of an adsorption type of
volatile gas purifier*
When an adsorbent becomes saturated it can be freed of adsorbed vapors
(desorption) by forcing steam through it. The steam and solvent vapors are
condensed, freed of water and partitioned by different methods; Florentine sep-
arators can be used in the case of immiscible liquids, such as gasoline and wa-
ter; the separation of miscible liquids, such as alcohol and water, can be ac-
complished by redistillation. Thus, it is seen that with the adsorption method
it is possible to remove from polluted air a great variety of vapors and gases
up to 100£ even when they are present in the air in high dilution.
In concluding this brief report on modern methods for air and gas purifi-
cation attention should be directed to the fact that by present methods air and
gases can be rendered close to 100/£ free of most acid and alkali gases, organic
solvent vapors and some other gases. But no effective and cheap method has been
found up to the present for the recovery of carbon monoxide.
Water
Vapor
1
er; 5
Fig. 7. Plan of the absorption setup
Air blower; 2 - cooler; 3 - absorber} 4 -
catch-
sorbent accumulator} 6 - solution accumulator* 7 —
8 — heat exchanger! 9 - heater} 10 — evaporator (va-
porizer)! 11 - fractionating column} 12 - deflegraator; 33
— cooler (condenser)} 14 - collector for final products.
-------
Purification of air from solvent vapors, such as gasoline, acetone, ace-
tates, etc. can be used effectively only in the case of tail gases and not in
the purification of ventilating air, even though it is effective in both in-
stances; the high cost makes its use for purification of ventilation air eco-
nomically prohibitive. The possibility of using solid absorbents, such as ac-
tivated charcoal and silicagel for the purification of ventilation air may ap-
ply to many cases. Faint shops in the automobile and airplane industry and in
rubber manufacturing, in plants producing artificial leather, etc. are equipped
with powerful ventilating installations which discharge air containing various
solvent vapors in concentrations less than 5 Bfi/1* Such a concentration makes
pollutant recovery economically unprofitable. The primary obstacle lies in the
high cost of adsorbent material and in the consumption of considerable electric
energy in overcoming the pressure drop of recuperating installations.
At full load recuperating installations normally create a pressure drop of
1000 - 5000 mm water column; ventilators used in technical ventilation are used
to overcome pressure drop of 50 - 150 mm water column* Therefore, for the pu-
rification of ventilation air from volatile solvent vapors it is necessary to
find a way to reduce the cost of adsorbent materials and to decrease the pres-
sure drop of filters. A challenging and urgent problem is the design and con-
struction of a solid sorbent filter having a pressure drop of 50 mm or less wa-
ter column. Purification by adsorption, by liquid solvents, or by chemical
means is at present done by a variety of scrubber designs. It is important that
these be standardized and built according to suitable specifications.
Problems related to practical air purification from gases and vapors are
under intense study at Trust "Gaso-Ochistka", which is, in effect the All-Union
State Trust of Electrical, Chemical and Mechanical Gas Purification and Bust
Elimination. Special problems of air purification
*" *_ /<**»
J. n. -i^8/o° from gases and vapors had been studied by many in-
stitutes, in particular by H10GAS or the Central
Scientific Research Laboratory for the Purification
activated
C>
-------
vestigated air and gae purification problems tc some extent. 1*he problems re-
lated to air purification can be defined as follows* to determine the exact
nature of hygienic purification of industrial emissions; to develop methods of
sanitary control over work on waste recovering and over the operation of de-
vices designed for the same purpose,! and to comply with the Sanitary-^gienic
air purity norms preccribed by the State Sanitary Cods.
Vapor
Closed
Open
t
Open
Besorption
» ^
Adsorption
Closed
I, I,
Water
\
9. Plan of system used in the adsorption of
volatile solvents' vapors by activated charcoal.
1. Section outlets; 2 - air conduit; 3 » flame
protector; 4 - air blowerj 5 - Ludlow valvef 6 -
adsorbers; 7 - activated cliarcoalj 8 - condenser;
9 - separator; 10 - valves; 11 - motor
-185-
-------
Zonal Study of Atmospheric Air Pollution in Areas Surrounding a
Booting Tar Paper Plant,
Ta. I. Shvarts and L. A* Zil'berg.
Proa Leningrad Scientific-Research Institute of labor Protection,
All-Union Central Council of Trade Unions*
Glgiena i Sanitariya, Bo. 7, 53-54, 1952*
The Riga Institute of Labor Protection studied the air in the vicinity of
a roofing tar paper plant ; determinations were made of the content of gases in
the atmospheric air between June 1930 and February 1951 through the slimmer,
autumn, and winter seasons* Air samples were collected on the windy side, and
2*5 m above tho ground on all sides of and at different distances from the
plant. Hydrocarbon determinations were made in air samples collected 50, 100
and 150 ra fros the plant; sulfur dioxide and dust determinations were made at
distances of 100, 150 and 250 m. A total of 79 analyses were made, which in-
cluded 32 tests for hydrocarbons, 17 for sulfur dioxide and 26 for dust. Hydro-
carbons were determined by the combustion method at 500 - 1000 9 with platinum
wire as the catalytic agent; resulting carbon dioxide was absorbed by baryta
water in accordance with the approved method of the Leningrad Institute of Labor
Protection* Sulfur dioxide was determined nephelometrically, using the electro-
photo— turbidimeter manufactured by the Leningrad Institute of Labor Protection*
Dust was determined gravimetrically*
Carbon dioxide determinations were saade in 13 air samples collected at 50
m from the plant . The concentration of carbon dioxide varied between 0*046 ~
0*302 mg/li of air* Thirty air samples aero taken 100 a from the plant, of
which 13 were tested for concentration of hydrocarbons, 11 for dust* and 6 for
sulfur dioxids* Concentration of hydrocarbons varied between 0*024 - 0,293
cg/lij dust between 1*? * 5*59 Eg/a » and of calftir dioxide batwosn 0*0056 -
0*0022 og/li* Twenty-four air samples were collected at 150 n frxm the plant*
of which 10 were tested for hydrocarbons, 9 for dust, and. 5 fox SOg. Concen-
tration of hydrocarbons variod frcs traces to 0.35 tog/lif only two of the ten
analyses showed a high concentration. Dust concentration varied from 1*25 -
4 &£/B • Concentration of sulfur dioxide varied froa 0,0092 - 0*017 &3/11*
Of 11 samples collected at a distance of 250 a from the plant, 6 were tested
-186-
-------
for dust concentration and 5 toT 30^* Ho air samples collected 250 m from the
plant were analysed for hydrocarbons. Dust concentration varied from 1.3 -
4*5 ofl/» * and salfUr dioxide from 0,0034 to 0.0176 mg/a » The results shoved
that the SO. air content fell at 150 a from the plant, but remained practically
unchanged at 100 and 250 m from the plant.
To obtain more accurate results with reference to the basic source of air
pollution, 8 additional laboratory analyses were made of air samples collected
1.3 km from the plant at a point far away from industrial establishments. Sul-
fur dioxide concentrations varied between 0*0012 - 0.0015 mg/lij and dust con-
centrations varied between 1*05 a&& 1.12 ag/m . The results indicated that at
points distant from the plant, dust and sulfur dioxide concentrations were con-
siderably below those found in close proximity to the plant. This uao taken as
evidence of the fact that air pollution in the vicinity, of the plant was caused
by the emiosion of gases and by the dust coming from the plant. Qa the strength
of the evidence produced by this investigation a resolution was adopted in 1953
to close the plant permanently. A new building site was provided where a new
roofing tar paper plant was then constructed in accordance with all sanitary
and technical requirements prescribed for the building of a tar paper plant.
A project has been initiated for the construction, of a gas purifier and
dust collector for use in the manufacture of tarred roofing paper.
-187-
-------
Acrolein as an Atmospheric Air Pollutant.
By
IS. V, Plotnikova.
Chair of Coaninunity Hygiene, Central Institute of Postgraduate Medicine.
Gigiena i Sanitariya, Vol. 22, Ho. 6, 10-15, 1957.
Acrolein is formed where fats or glycerine are subjected to the effects of
temperatures of 130 - 2?0 5 in foundry's core divisions, in the electro-tech-
nical industry, in the preparation of insulation material, in tiaplating, in
tinsmithing, in the manufacture of oil cloth and linoleum, in the manufacture
of dryir.g oils and stearine, in hydrogenation of ucsaturated oils, in the manu-
facture of oils, in lard rendering, in bone processing, in remelting of typo-
graphical material coated with fatty dyes, etc* Acrolein, CH^CH-CHO, is the
simplest of the uusaturated aldehydes; it has an irritating stifling odor; its
vapor is 1.9 times as heavy as air.
Many methods have been described for acrolein determinations the benai-
dine method, the fluoroglucine method, the iodometrie, pyrogallio, fuchsia sul-
furous acid, and monoatomio phenol concentrated sulfurio acid methods. These
are all colorimstric methods and have in common the disadvantages of non-speci-
ficity and non-sensitivity. The funchsin sulfurous acid method has been used
most widely in sanitation work. Despite the fact that this method is insuffi-
ciently accurate and is subject to gross error, it has been used in scientific
research and in air pollution control work. The method is based on the forma-
tion of a reddish-rose color produced by the reactions taking place between
acrolein and fuchsin sulfurous acid. Other aldehydes also produce a color with
the fuchsia sulfite reagent, so that the method does not determine acrylaldehyde
specifically but total aldehydes, according to V. H. Granenova and V* A. Hold-
ovskii.
In 1955 the Leningrad Scientific-Research Sanitary-Hygienic Institute made
a study of .the atmospheric air in the environs of the "Zhirccrabinat" of Lenin-
grad (Fat-CQ&bine). The report showed that the content of acrcloin in sotae in-
stances reached a concentration of 37*4 mg/a . The averago concentration of
acrolein in dwellings situated 200 meters from the combine was 8*44 otg/m . The
Astrakhan Municipal Sanitary Epidemiological Station taado a similar study in
-18ft-
-------
the environs of the Mikoyan combine in 1934 - 1935* The workroom air contained
42 mg/m of acrolein. We considered such results as unreliable; according to
H. V. Lazarev and A* Patty above concentrations of acrolein could not be toler-
ated "by man even for as short a time as one minute. The lack of a specific
method for the determination of acrolein throve doubt on the data heretofore
presented regarding the concentration of acrolein in atmospheric or workroom
air* We used the specific method for acrolein determination proposed by 3. P.
Senderikhina in Gigiena i Sanitariya, 1947, Ho. 3, 17-19*
The principle of the method is as follows t acrolein reacts with tryptophan
(p-indol aminopropionic acid) forming a stable violet color* The technic is as
follows: Into each of two Poleshaev absorber tubes place 2 ml of absorption
solution made with distilled water, HC1 of 1.19 ep« 5?* and alcohol in propor-
tions of Ii2.5:0,5. Immediately prior to collecting the air sample add 0.2 ml
of 0,25£ tryptophan) the latter is prepared in small portions by dissolving 0.2
g of the tryptophan in 10 ml 0.1 H HC1; this must be kept in the dark. The ab-
sorber tubes are set into a glass container imbedded in snow, and the air aspi-
rated at the rate of 20 li per hour. At such a rate only a slight amount cf the
aspirated air is carried over into the second absorber tube. Ho air was carried
over into the second absorber tube at a rate of air aspiration of 10 li per hour,
At the completion of the air sample collecting pour the absorber solution into
a colorimetrio tube; place into a waterbath at 40 - 45 for' 30 minutes, then
make the colorimetric determination using standards prepared from known dilution^
of aoroloinj acrolein standards prepared before-hand retain the color without
change or fading throughout the working day.
The tzyptophan method yielded good results under laboratory conditions}
however, we encountered some difficulties in our studies of the air In the en-
virons of the industrial plantc We.were unable to obtain positive results with
the air around the drying oil plant where the odor of acroloin was clearly per-
ceptible. All air samples produced a yellow color with the absorber solution
instead of a violet color. Some thought this was due to the fact that the
aorolein in the air rapidly polymerised.and disappeared from the atmospheric
air aa such, and that its polymers still possessed the irritating stifling odor;
others thought that the odor was due to different volatile substances formed in
the course of oil boiling. Laboratory check-testa did not confirm such assump-
tions. The control tests were made as follows* A drop of acrolein was placed
-189-
-------
into a 6.375 li capacity flask and hermetically sealed. At intervale of 30
minutes 100 ml of the air was taken from the flask and replaced with 100 ml of
air to avoid vacuum formation. Tola waa done over a period of 6 hours* All
samples shoved the presence of acrolein. the concentration of which "became
gradually lower in proportion to its actual dilution by the acrolein removal
and air substitution* This indicated that polymerization of acrolein occurred
at a slow rate and that it must have been present in the air surrounding such
manufacturing establishments as drying oil plants*
The opinion was also expressed that no acrolein was formed at temperatures
as low as 130 - 150°, which prevailed in the processing of the drying oils at
that factory* We placed some linseed oil into a glass flask and heated it to
130 - 150 , The vapors issuing from the flask were directed into a hood from
which air samples were taken. All this was done under controlled laboratory
conditions* Tests showed that acrolein was definitely formed at that range of
temperature. However, it was found that other organic compounds were generated
with the acrolein. presumably ketones and fatty acids y which in the presence of
the tryptophan produced a yellow color, thereby interfering with tha original
determination, the high sensitivity of the tryptophan method was known to ua.
We, therefore, resorted to the aspiration of air volumes not exceeding 2-3
liters; after heating the sample over the watorbath as prescribed, we obtained
a violet color, entirely free from the masking yellow tint. Accordingly, we
proceeded with our practical investigation of the air by aspirating small air
volumes.
In the factory under study siccatives are prepared at 220 - 270°, natural
drying oils and oxyl drying oils at 130 - 150 . The plant is equipped with
acrolein absorbing installations based on the absorption of acrolein by water
spray. Residential dwellings, a school for ten-year old youngsters and other
establishments and institutions were situated 25 meters from the plant. In
this area the irritating odor of aorolain was felt constantly. Samples were
taken on the lee side of the plant, Analytical results are presented iaa the
Table. The recorded data show that acrolein waa present in the atmospheric
air in considerable quantities even at great distances froa the source of ita
discharge* The concentrations of acrolein in the atmospheric air recorded by
us were markedly below those found in the literature and as recorded by the
Leningrad investigators} the reason for that was discussed by ua in one of the
preceding paragraphs.
-190-
-------
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the eyes and of the naso-pharyngeal passages. At 1 mg/n aorolein concentra-
tion all test Individuals experienced alight irritation of the mucosa' of the
eye and a stinging sensation in the nose* For 8 of the tested individuals
the minimal perceived acxolein concentration was 0.8 mg/m and for the re-
juaining two 0.9 mfi/m . The maximal non-percepitable concentrations ranged
Between 0.7 and 0.85
The presence in atmospheric air of odors of any type is not a matter of
indifference to man. Unpleasant odors produce a feeling of sickness; and it
is well known that by way of unconditioned or conditioned reflexes unpleasant
odors exert unfavorable effects on many functions of the organism. We, there-
fore, undertook to determine the threshold of reflex effect of acrolein on
opitc&l chronaxy, on the respiratory rhythm and on dark adaptation. We used
the 1949 "GIF" chronaximeter. Under study were three individuals. The threah-
05
3
old of olfactory perception of acrolein for two of them was 0.8 mg/ffl and 0*9
mg/m for the third one. Test individuals were given a 5 days period of train-
ing. Following this determinations were made of the rheobase and chronaxy of
each upon the inhalation of different concentrations of acrolein. As a first
step triple determinations were made of the chronaxy to establish a background
for each of.the test individuals, then each test individual was made to inhale
known concentrations of acrolein for three minutes, at the end of which measure*
ments were taken of the rheobase and of the chronaxy. Pure air was administered
intermittently to obviate the formation of conditioned reflexes to the existing
study conditions.
The results showed that in concentration of 1.5 og/m acrolein brought
about a reduction of the chronaxy in two individuals and a prolongation in one.
Within 3-5 minutes the chronaxy returned to the control level. Ho change in
the rheobase was observed in any of the test individuals. Inhalation of 1»5».
1.0 and 0.8 rag/o of acrolein, similar to the inhalation of pure air, produced
no changes in the values of the rheobase or of the chronaxy. The threshold of
reflex effect of acrolein, determined by the method of optical chronaxy was
at 1*73 mg/m * The results of the tests of one of the individuals are plotted
in Graph 1. . .
Aorolein effect on respiration nas studied on 3 test individuals with the
aid of the usual pneumograph. Results of the tests showed that 1.3 mg/m was
the lowest concentration of aoroloin which brought about pneumographio changes
-192-
-------
fi»
flii
«6tf
I ^fc ft rt ' J
/ x^tf/*/**
1
Acrolein
-1
(170 -
Q6S -
060 •
WO -
Q60 -
070
0.65 •
fiKfi
/\ 175^ V
/ \ L "e/"
i
Acrolein
i
Acrolein
Air,
f~T~
in all three test individuals* The changes
were expressed in the form of lowered res-
piration frequency and uneven amplitude of
the respiratory waves (variations between
Time in 5
intervals.
0.4 cm). 1 mg/m appeared to be
the respiratory threshold concentration.
Determinations of eye sensitivity to
light cere made in three test individuals
with the ADU adapt ometer at normal temper-
ature and humidity, in perfect quiet and
in the absence of any odors. The individ-
uals were examined preliminarily and were
found to have normal vision and odor per-
ception. As another preliminary step these
individuals were tested on several days to
determine their usual, or initial, curve
of dark adaptation. After this, tests were
made to determine changes in the dark adap-
Fig. 1. Effect of acrolein on tation cupves following the inhalation of
optical ohronaxy.
low acrolein concentrations. Acrolein was
administered on the tenth minute of adaptation for 5 minutes. Results of this
study, shown in Graph 2, indicated that 2 mfi/m of acrolein "brought about a
levering in the eye sensitivity to light. Acrolein concentration of 0.8 mg/m ,
which was the threshold concentration of olfactory acrolein perception, and of
0.6 mg/m brought about a notable increase in tho eye sensitivity to light,
which gradually returned to normal within 40 minutes of dark adaptation. In-
halation of 0.5 me/in of acrolein for 3 minutes, like pure air, had no effect
on the eye sensitivity to light. • - • '
Conclusions.
1. Atmospheric air pollution with acrolein discharged from a drying oil
factory extended as far as 1000 meters from the source of pollution in concen-
trations exceeding the allowable limit.
2* The threshold of olfactory acrolein perception for the majority of the
teat individuals was at 0.8 mg/m .
-193-
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Acrolein concentration in mg/ai
Tig. 2. Changes in eye sensitivity to light on the 15th
minute of adaptation to the dark in test subjects I, II, III,
3. The threshold of acrolein effect on the reflex reaction and on optical
was at 1.75 nsg/o , and at 1.5 mg/n in the case of respiratory rhythm
and wave amplitude*
4. The threshold effect of acrolein on the functional state of the "brain
cortex as indicated ty changes of reflex reaction and determined adaptometrically
was established at 0.6 mfi/m » which is below the threshold of acrolein odor
perception.
5. Tests indicated that 0.3 mg/m of acrolein can be taken as the limit
of allowable maximal single concentration.
6. The sanitary clearance sone of 100 maters prescribed by our present
sanitary regulation for drying oil factories is regarded as inadequate.
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Present Day Conditions of Atmospheric Air Pollution "by Automobile Exhaust
Gases in Cities and Problems of Its Control.
By H. K. Hedogibchenkp.
Chief State Sanitary Inspector, Main Government Sanitary Inspection
Department of the D. S. S. R. Ministry of Health.
Gigiena i Sanitariya Vol. 23, No. 8, 1958, pp. 6-9.
The extensive development of industiy and of motor transport vehicles dur-
ing the sixth Five-Year Plan brought into sharp focus one of the moat important
problems of health, namely, the sanitary protection of community atmospheric
air against pollution with industrial discharges and wastes, and to a consid-
erable degree with motor vehicle exhaust gases.
In accordance with the Directives of the 20th Conference of the KPSS (Com-
munist Party of the Soviet Union) regarding the sixth Five-Tear Plan for 1956-
I960) production of motor trucks is to be increased by 32^ and the total load
capacity "by 45? 5 the number of buses is to be increased by 88S& and of passenger
cars lay 86j6. Production of 40 - 50 to*1 dump-trucks is now in the process of
organization. Production of several types of automobiles is also due for an
increase. In connection with this the problem of atmospheric air pdllution
with automotive exhaust gases in cities compels serious attention. Exhaust
gases of motor transport vehicles emit into the atmosphere carbon monoxide,
soot, tarry substances containing carcinogenic principles, such as 3,4-benz-
pyrine, oxides of nitrogen, and, when motor fuel 10 reinforced with tetraethyl
lead, also lead compounds. One of the basic current problems is to eliminate
carbon monoxide pollution from atmospheric air.
Laboratory studies of atmospheric air in cities showed that carbon monox-
ide concentrations in the streets of large cities exceeded the permissible lim-
its. Thus, in Moscow, in areas of specially intensive motor traffic, maxinrnin
concentrations of carbon monoxide reached 100 - 200 mg/m . In Leningrad, on
the main highways, with traffic reaching 3000 motor vehicles per hour, carbon
monoxide concentration reached up to 128 mg/m , while in streets with moderate
traffic carbon monoxide concentrations were at times as high, as 145 - 1^4 mg/m
In Saratov carbon monoxide was found in concentrations of 20 - 60 mg/m . In
Perm maximum concentrations of carbon monoxide amounted to 40.- 60 mg/m , while
in Ivanova carbon monoxide concentrations ranged between 18 - 88 mg/m . Motor
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transport vehicle exhaust gases, and in particular carbon monoxide, in high
concentration are not limited to city streets. In isolated instances carbon
monoxide was found in Moscow on the 4th floor balconies in 28 mg/m concentra-
tion, and in living quarters in 10 - 20 mg/m concentration. Carbon monoxide
was found not only *ln air samples collected on sidewalks of main city streets,
but.in the air of nearby small park areas and gardens where the concentration
of carbon monoxide was as high as 18 mg/m .
Although carbon monoxide is lighter than air, it diffuses very gradually.
Investigations made by A. S. lykov of the Leningrad Medical Sanitary-Hygienic
Institute showed that an idling motor created a carbon monoxide concentration
up to 182 mg/m at a distance of two meters from the exhaust point, and an
idling motor of a .passenger car at same distance created a CO concentration up
to 78 mg/m . After the motor was cut off, carbon monoxide air concentration
became gradually reduced; however, after 9. - 10 minutes, carbon monoxide con-
centration in the air still amounted to 12 - 30 mg/m ; after 12 - 15 minutes
the air samples became negative for CO.
Experiments carried out by the Scientific Research Institute for Automo-
bile and Motor Transport under practical working conditions showed that exhaust
gases of the "Moskvich** automobile contained, on the average, 1% of carbon mon-
oxide, while exhaust gases of 2IL-150 trucks contained 4# of CO, Cases were
recorded when exhaust gases contained 7-9 and even 11% of carbon monoxide*
On the average, exhaust gases of passenger cars and autobuses contained 6.3%
of carbon monoxide. Carbon monoxide content fluctuated between 1 and 13.7^
depending upon the type of motor fuel and, above all, upon the working condi-
tion of the motor. In the process of burning 1000 kg of gasoline the passenger
car "Moskvich" emitted into the atmospheric air 800 kg of CO.
Such intensive pollution of atmospheric air with exhaust gases of motor
driven vehicles violates the sanitary living conditions of the population. In-
vestigations made by the Leningrad Medical Sanitary-Hygienic Institute and by
the F. F, Erisman Moscow Scientific-Research Institute of Sanitation and Hy-
giene of the R. S. F, S. R. Ministry of Health revealed that prolonged exposure
to CO concentrations In the vicinity of motor driven traffic caused notable
changes in the blood composition of OHTB workers, in particular of polyglobulin,
and revealed the presence of carboxyhemoglobin. The examined persons complained
cf headaches, vertigo, weakness in limbs, etc. Complaints of headaches and
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of dizziness were most frequent. Carbon monoxide concentration in atmospher-
ic air should not exceed 6 mg/rn in single tests and 2 mg/m in average 24
hour tests*
. From the sanitary viewpoint the lead content in the city air, created by
•
transport vehicles using ethyl-lead gasoline is of no lesser significance,
When 'ethylated gasoline is burned, oxides of lead and other lead compounds are
formed which are partially deposited within the motor and partly discharged
into the atmospheric air; according to some data lead deposited in the motor
amounted to 63% while 31% escaped with the exhaust gases. According to data
of foreign authors 36 g of lead emitted with exhaust gases are deposited year-
* 2
ly on 1 m of a small town street (Schwartz). In Zurich 100 kg of lead were
deposited in the course of one year on the main streets of Tzecger city. In-
vestigations of the P. P. Erisman Moscow Scientific-Research Institute of
Sanitation and Hygiene of the R. S. P. S. R. Ministry of Health showed that in
burning 1 kg of ethylated gasoline an idling GAZ-51 motor discharged into the
atmosphere 0.3. g of lead; running at a speed of 15 km/hr it emitted 0.8? S a*1*1
at a speed of 40 km/hr - 0.92 g.
In 1956 the Institutes of Hygiene of Hoscow, Riga, Sverdlovsk, Ivanova,
Perm carried out investigations of atmospheric air pollution with motor trans-
port vehicle 'exhaust gases containing lead. In Sverdlovsk the lead content in
the exhaust gases ranged betueen 0,069 - 3-7° mg/ni , depending upon the make
of the motor vehicle. In the atmospheric air of a street with heavy motor traf-
fic lead was found in concentrations exceeding the maximum permissible limits
of O.OQQ7 mg/Ei » Lead was found in the water used by traffic officers to wash
their hands in, as well as on the inside and outside surfaces of domestic win-
dow panes and. on automobile windshields, Particularly large quantities of lead
were found on leaves of shrubs and trees. Thus, in isolated instances in the
Riga-Kirov square up to 15-5 sng/m of lead sas found on the leaves of a linden
tree. It should be noted that at the time of the investigation not all the
motor transport vehicles of Riga raere using ethyl-lead gas; the quantity of
lead pressent in the air of Riga would have been several times greater had all
automotive vehicles used ethylated gasoline at the time.
!Phe P. P. Erisman Moscow Scientific-Research Institute of Sanitation and
Hygiene of "the R. S. P. S. R. Ministry of Health carried out investigations in
Koscow in connection with the utilization of ethylated gasoline by the passen-
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ger auto transport only. Prom 0.001 to 0.003 cag/m of lead was found in the
street air. Thus, at present, when only public auto transport vehicles are
using ethyl lead gasoline the Moscow air is polluted with lead along the traf-
fic, route and at the stopping points of public auto transportation. It must
"be noted that no industrial plants releasing lead into the atmosphere existed
close to the points of investigation. No lead was found in air samples taken
from streets with light motor-transport traffic in the above cities. Analysis
of the collected data on actual lead in the air of the cities showed that the
demonstrated lead concentrations could not be safely regarded as of no signif-
icance for the health of the population. Investigations by Soviet and foreign
authors disclosed in auto transport exhaust gases the presence of a polycyclic
hydrocarbon, 3,4-benzpyrena, generated at the rato of 0*75 Bg/min.,
According to most recent reports auto transport exhaust gases were polluting
atmospheric air also with nitric oxides; the more incomplete was the gas com-
bustion the greater was the quantity of formed carbon monoxide and less of ni-
tric oxides were emitted into the air; vice versa, the more complete the gas
combustion the less CO was formed and the more nitric oxides were discharged
into the air. This problem requires immediate study, and.hygienists and tech-
nological engineers should regard the problem as an urgent one, the solution
of which should not be unduly postponed.
Hext in importance to air pollution with carbon monoxide is air pollution
with soot discharged in large quantities with automobile exhaust gases. The
cause of this type of atmospheric air pollution lies.in.the unsatisfactory
technical construction and mechanical and functional adjustment of the engines.
Existing designs of automotive motors violate sanitary requirements "Sy dis-
charging into the air above mentioned harmful substances. Design and construc-
tion of new types of motors the exhausts of which should contain no harmful
ingredients are developing extremely slowly.
Under presently prevailing conditions only the brakes are checked before
the motor car gets off the assembly line, while the motor performance and in
particular the performance of the carburetor are not checked. As a result,
auto vehicles are frequently seen in the streets offensively fuming due to
improperly adjusted fuel feeding, and combustion; the exhaust gases of such
motors were found to contain up to 11$ of carbon monoxide, while the same motors
when properly adjusted exhausted gases containing not more than 2 - 3% of car-
bon monoxide. Use of gas analyzers (alphameters) in garages showed that they
-198-
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could be employed for control of motor combustion processes to indicate when
carburetor adjustment should be made before the motor vehicle was released by
the factory or Toy the garage. However, production of these devices is still
in an unorganized state.
The NAMT Institute and tue Scientific-Research Institute of Industrial
and Sanitary Gas Purification (NIIOGAZ) undertook to solve the problem of re-
ducing the emission by motors of autovehicles of products of incomplete com-
bustion. STork oh this problem has been in progress for more than 7 years,
but basic difficulties presented t& this problem still remain unsolved. The
same is true of the problem of elimination of malodorous and irritating sub-
stances exhausted with the gases by Diesel-engine operated buses any. trucks.
Early solution of such urgent and important problems as the elimination
from auto—transport exhaust gases of carbon monoxide, carcinogenic substances,
nitric oxides, etc. constitutes the pressing task of the Institutes of NAlfi,
HTIOGAS and of the Ail-Union Scientific-Research Institute of Automotive Trans-
port (VNIIAT). The reduction of city air pollution caused by auto-transport
exhaust gases should be carried out along the following basic lines:
1. Improvement in the design of automobile motors and carburetors with
a view to increasing degree of combustion and of gasoline utilization. This
applies equally to motor engines using other types of fuel.
2. Development of methods to render harmless exhaust gases emitted by
auto-transport engines, preferably by oxidizing them to smaller non-harmful or
less harmful molecules.
3* Strict periodic checking of the performance of the engines and organ-
isation of large inspection and adjustment centers where carburetors, distrib-
utors, spark plugs, feeding lines, etc. can receive, a thorough examination.
4. The production of domestic alphameters should be improved and speeded
up to facilitate checking and determining required adjustments in automotive
engines. •__..-
5- Fuel quality, should be improved by increasing the octane number and
by any other suitable means, and the addition of tetraethyl lead should be
discontinued.
-------
Sulfurous Anhydride in the Atmospheric Air of Leningrad*
**
V. T. Lenshin.
Gigiena i Sanitariya, Vol. 23, No. 8, 57-59, 1958.
This ia a report on an effort to establish a connection between concen-
tration of sulfur dioxide in the atmosphere and certain meteorological con-
ditions. The report is based on a study made in Leningrad by V. H. Guskova
and published in 1951. The study presented results of 313 determinations of
SO- made in four separate locations in Leningrad; it consumed 130 days over a
period extending from February 1957 to February 1948* A comparative study of
the temperatures and S02 air concentrations of air samples taken at the time
substantiated the inverse ratio previously established. This inverse ratio
appears more pronounced when monthly averages of SO. concentrations are com-
pared with monthly air temperature averages* In these comparative studies at-
mospheric instability and turbulence were taken into account*
The experimental data of Guskova uore subjected to statistical analysis
the results of which verified the above conclusion* It is enough to mention
that the monthly S02 average concentrations compared with the monthly average
temperatures in Leningrad, computed over a period of many years, shoved a
correlation coefficient; r « -0*90, for the cold and narm half of the year
alike.
The correlation between the S02 monthly average concentrations and the
monthly average temperatures of the Leningrad air recorded for the period of -
February 1947 to January 1948 inclusive, showed a still higher coefficient of
correlation, namely:
r., « -0*9^ for the cold period, between Hovember 15 and April 15* and
r» m -O.98 for the warm period, between April 15 and November 15*
The high correlation coefficients pointed to the existence of a linear
functional relation between concentrations of S02 and the temperatures of the
air for the entire year. . . -
On the basis of the high magnitudes of correlation coefficients, the suf-
ficient number of observations, and the constancy of the investigated series,
it is possible to derive generalizations expressing the correlation between
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the mean monthly SO. concentrations and the eean monthly temperatures of the
air for the season when fuel is used and for the season when no fuel is used
for heating purposes* The generalizations ares
for the heating season, d - ' and d - * and
for the unheated seaaon, d . '< and d . " 9'11 *.
4.64 4.536 '
where d ie the mean monthly concentration of SO- in ag/m
t is the mean monthly temperature of the air in degrees*
Sine® d is a statistical function of t, or vice versa, it follows that
for any given value of t there is a corresponding value for d; on the oasis of
this principle trao generalizations sere derived for each of the above two sea-
sons of the year*
The fact that correlation equations exist in pairs makes possible to as-
tablioh the mean quadratic error, i.e., the degree of precision with which the
equations can be solved for the heating and unhaating seasons. It is not dif-
ficult to see that the precision in solving the equations for the unheating sea-
son will exceed that for the heating season. This is due to the fact that the
functional relationship between SO. concentration and temperature of the air
follows a truer course at higher temperatures*
A lower correlation coefficient for the heating season, i.e., r. < r,,,
and a rise in the quadratic errors at loser temperatures point to deviations
in the relation between d and t due to the effect of other factors which become
more pronounced under the particular set of conditions.
7* A. Byasanov pointed out that there also existed a correlation between
SO. concentration and barometric pressure, wind velocity and air humidity. It
is apparent that cold season anticyclone weather conditions make those relation-
ships sore pronounced with a corresponding lowering of the relationship bstcoen
d and t.
Regional olicatologie data manifest a great variety of wind-rosettes, shich
are characteristic for different months of the year for a given region. Saa>-
pliug of the air in several locations of the region and obtaining monthly aver-
ages of analytical results negate the effect of the wiiuU If, under such oir-
cuastancsEJ, the correlation between SO. concentration and air temperature is
regarded as the basic one, and the correlations with barometric pressure, air
humidity, etc., as incidental; then the values of their coefficients will i&r~
-------
crease with lover temperatures only to a slight degree and in most cases may
be disregarded,
The mean Leningrad temperature of many years was 4.2°, on the basis of
calculations herein indicated its correlated S02 concentration should vary
between 0.062 - 0.063 ma/m » which coincides with average SO 'concentration
for the month of October.
The computed semi-annual indices of S00 concentrations in Leningrad for
•y £
the years 1947 and 1946 in mg/o weres
1948
Warm period 0.034 0.033
Cold period 0.179 0.150
Results of the statistical analysis of the data support th® assumption
that the SOp transformations from the gaseous to the liquid state, or vice
versa, at temperatures above or below -10 do not disturb the statistical
correlation to any appreciable degree, and in this lies one of the advantages
of the aspiration method for the determination of S0_ concentration in the air
as compared with the sedimentation method widely used abroad.
It is believed that the stability of the correlation coefficients through
the year indicates that S02 is constantly present in the atmospheric air of
Leningrad, its re-distribution in time and space j that within the range of
monthly averages the processes of pollution and self-purification of the at-
mosphere acquire even levels; and that all such Banifestations are the results
of the dynamic continuity of the process.
The main causes of the seasonal SO- concentration fluctuations in the . .
Leningrad atmospheric air aro in the quantity of mineral fuel burned and the
seasonal changes in the vertical temperature gradient, y? these were clearly
reflected in the inverse correlation between the SCU concentration and also
temperatures arrived at on the basis of S02 determinations made in four sepa-
rate locations through the year, a .procedure uhich negates the raiad effect on
the SO. concentration. The wind factor depands entirely on meteorological
conditions; it predominates not only in Leningrad, but also in such largo in-
dustrial centers are Kharkov, Eostov-on-Don, etc., where close to the ground
radiation inversions occur more frequently and are more pronounced.
Conclusions.
1. Contrary to apparent obviousness, the assertion that the monthly av-
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erage SO^ concentration in a given region depends principally on the cold
(heating) or waxta (non-heating) seasons of the year IB inaccurate.
The rise in S02 concentrations during the heating season results not only
from the greater amount of burned mineral fuel, but is also the result of un-
favorable meteorological conditions.
This author is of the opinion that S02 concentration close to the ground
during the cold season of the year is due to the greater air stagnancy in cold
weather and to the prevailing radiation inversion, especially in anticyclonic
weather; and, in addition, SO. is more soluble in the air-suspended moisture
at louer temperatures*
A 1 drop in the temperature during the cold season of the year results
in a three times greater increase in S02 concentration than under similar con-
ditions during the uaim season of the year. By ih« combined solving of the
generalizations derived for the heating and non-heating seasons it uae estab-
lished that a sudden rise in the concentration increase from the warm to the
cold seasons occurred approximately at 4*2 . Accordingly, computations of
monthly average S0? concentrations at temperatures above 4.2 should be made
by the empirical formulas intended for the warm season; and at temperatures
lorjer than 4.2 by the empirical formulas intended for the cold season of the
year.
With the aid of the formulas it was shown that at temperatures above 31
strong turbulence and convection developed which sent the total combustion
originated SO. upward. Close to the ground air temperatures approaching 30°
were observed in Leningrad only on rare occasions, when only traces of 302
were found in the air.
2* The greater was the amplitude of the course of daily temperature,
the greater was the temperature gradient amplitudes during the day, and espe-
cially in t^e summer, the upper diabatic gradients rose to high values, and
at night, especially in the winter, the inversions became profound; hence,
lowest SO- concentrations occurred in the summer days and highest SOg concen-
trations in the winter, between midnight and sunrise.
With the increase in the vertical temperature gradients after sunrise and
mth dispersion of the lower part of the close to the ground inversion, the
maximal S00 concentration in the close to the ground air most probably will be
found at progressively higher levels, that is, the lower half of tho close to
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the ground inversion, which ia characterised by a less intensive maes inter-
mixing, while the stagnation will acquire & stepped-up relative humidity.
3. Since the effect of fuel-combustion-originated SO. is more pronounced
during the wintertime, it is recommended that industrial establishments ia
large centers hum only high grade fuel poor in sulfur components during the
nighttime and early mornings; this will help to prevent toxic fog formation,
particularly on frosty or foggy days.
All Leningrad large Industrial enterprises should have adequate reserve
supply of high grade coal to be burned during unfavorable ateieorological con-
ditions, such as radiation inversions, dense smokes and foga.
Bibliography*
JIHTEPATVPA
AjieKcecaa M. B.. BymryeBa K- A. Pur. B can.. 1954. *& 4, crp. 13—16.—
aeuP. A. Taai me. 1940. *& 9 cff>. 7—15.—O H as e. Sgrpfunemie ropoAotoro BOS-
M., 1948. — EymTyeea K. A. far. H can., 1954, *& 11, crp. 11—13. —Fox bji-
6 c p r M. C. CaHHTapHan oxpana Boanyxa. M., 1948. — fycbicoea B. H, B KB.: Bonpocik
rHreeHu aTBeoctfrepHoro eoaAyxa. Jl, 1951, crp. 56—60. — ripcAea*Ho AonycnMUit KOHuea-
rpaitHH aTMOciJiepHUX aarpnauemiiL flon pejx. B. A. PaaaHoea, B. I B II. M., 1957. — P •-
:s a a o & B. A. CaBHrapaan oxpaaa arnocJiepBOni BOSAyxa, M* 1954.
nocrymua 2S/XI I9SB r.
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. The Toxicity of Vapors of Organic Mercury Compounds (Bthylmercuric
Phosphate and Bthylmerourlo Chloride) in Acute and Chronic Intoxication.
(Experimental Data).
I. H. Trakhtenberg.
(Department of Industrial Hygiene, Kiev Medical Institute).
Oigiena i Sanitariya, Ho. 6, 13-17, 1950.
A comprehensive hygienic and toxicologlcal investigation of organic mer-
cury compounds used in industry and agriculture is becoming the pressing neec
of today. These compounds are widely employed "by industry as uood preserva-
tives, as agricultural fungicides, and as antiseptics in medicine. Concen-
trations of mercury vapors at the level of inhalation in workrooms frequently
greatly exceeded the ma-rimm permissible concentration adopted for mercury vi
por (Malyahev, Witto and Axelrod, Braginekil and Fel'dberg). It was demon-
strated experimentally that the toxicity of organic mercury compounds exceed*
that of corrosive sublimate (Medved, Pravdin and Kremneva). It aas shown the
basic differences existed in the effect on the central nervous system of or-
ganic and inorganic mercury compounds* Medved and Serebryanaya maintained
that organic mercury compounds had a marked toxic effect on the cardiovasculi
and respiratory systems*
This author investigated the toxicity of vapors of organic mercury com-
pounds, such as othylmercurio phosphate and ethylmercuric chloride, and vapor
of inorganic mercury compounds. on a comparative basis. The compounds studiec
were the active ingredients in HIUIF-1 (aqueous solution of ethylmercuric
phosphate) and "granosan" , or ethylmercuric chloride thinned by talc; both
are extensively used in agriculture. In 1949 this author studied the workin
conditions prevailing in the use of ethylmercuric chloride as a fungicide in
the Kiev oblast. Concentrations in which this substance was found in tfco oz*
ganism of the workers are shown in the following Table. Identical results
were obtained in a similar study of ethylmercuric phosphate vapor. A compar,
tive study was oade of the toxicity of metallic mercury and of the two organ.'
compounds; white mice sere used in acute and chronic toxicity tests. In the
acute experiments use saa made of 3 desiccators of 4*5 liters capacity. Pet*.
dishes containing ethylmercuric phosphate solution aere placed in desiccator
-205-
-------
Herourj concentration in the air resulting from dry treatment of eeeda
with "Granosan" preparation (ethylmercurio chloride).
Test
Ho.
o*
KolkhoE
t Equipment i
Where _,_..,_
t treated 1 used
t of air
10
11
Providna
In the
Ditto
Ditto
Ditto
Ditto
Ditto
Ditto
Iron keg;
not sealed
ti^itly
Ditto
Ditto
Ditto
Close to the treat-
5
6
7
8
Chervonyi
Boets, Selo
Rodnikovfca
Ditto
Ditto
Ditto
In a
closed
barn
Ditto
Ditto
Ditto
Open
wooden
barrel
Ditto
Ditto
Ditto
Voroehilovy
Solo
Dmitruahki
Under a
Ditto
Ditto
Ditto
Ditto
In a
tightly
sealed
"psp-05"
apparatus
Ditto
Ditto
One ra to the lee
side of treatment
apparatus
One m to the wind-
ward side of treat-
ment apparatus
Close to treatment
apparatus
Ditto
One m from treat-
ment apparatus
Two m from treat*
ment apparatus
Close to treatment
apparatus
0.000045
0.000050
0.000035
0.000020
0.000150
0.000200
0.000070
0.000030
0.000025
12 Ditto
Ditto
Ditto
Ditto
0.000025
0.000010
0.
Ditto
One m from treat-
ment apparatus
Two m from treat-
ment apparatus
No. 1? crystals of ethylmarcizrio chloride in desiccator Ho. 2, and metallic mer»
cury in desiccator No. 3. ?he mice were placed inside screen inclosures sus-
pended from the top of the desiccators. Each desiccator was connected on one
side with the ouier air and on the other side with two absorbers filled with a
solution of iodine in an aqueous solution of potassium iodide. The absorbents
were connected with two water aspirators which insured a controlled flow of
fresh air to prevent CO. from accumulating in the desiccators during the ex-
-206-
-------
perlinent} and at the same time ensuring the constancy of vapor concentration
in the three desiccators. Air was drawn through the desiccators at the rate
of 1 liter every 10 minutes.
Animal exposures lasted 5 hours at mercury concentrations in hundreds and
thousands of milligrams per liter of air. The mercury vapors were determined
by S. Plisetskaya's modification of the Folezhayev nethod, based on the color-
i me trie determination of the precipitated complex CuI'Hgl- which is of a red-
dish-orange color. The modification has many advantages over the original
method.
Results of the acute experiments showed that ethylmercurie phosphate con-
centrations equivalent to 0.01 - 0.04 nig of Hg per liter of air and at ethyl-
mercuric chloride concentrations equivalent to 0*03 - 0.04 nig per liter of air
the mice began to die during the third to the fifth hours of exposure, depend-
ing upon the vapor concentration. Concentrations of either substance above
0.04 mg/li killed the mice within the first hour of exposure. Concentrations
of metallic mercury of 0.03 - 0,04 mg/li failed to c&use the death of the ex-
perimental animals even after 8 hours exposure. However, depending upon the
concentrations of the Eg vapor, the mice died 12 to 16 hours after the exposure
was discontinued. It was not possible to experimentally create metallic mer-
cury vapor concentrations exceeding O.O8 mg/li.
With ethylmercuric phosphate vapor concentrations in the air equivalent
to 0.006* to 0.009 mg of mercury per liter and with etbyImercurio chloride va-
por concentrations equivalent to 0.007 to 0.001 mg/li the animals died 6 to 15
hours after exposure. Mice exposed to identical concentrations of metallic mer-
cury vapor did not die, as a rule. Acute vapor poisoning followed a character-
istic course of development. At the beginning of exposure the mice became rest-
less, rushed from corner to corner, rubbed their snouts and at times crawled
into the cotton bedding. This stage of excitement usually lasted 15 to 20 min-
utes and was followed by marked depression. The mice became listless, sluggish,
huddled into groups, reacted only slightly to stimulation, and respiration be-
came fast. This was followed by symptoms of impaired equilibrium and a slow,
The organic mercury compounds under study are very stable; and since factors
capable of causing their breakdown were lacking, the concentration of the two
organic compounds was determined in terms of mercury per liter of air.
-207-
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staying gait* Paralysis of the hind leg* set in gradually and, as the intoxi-
cation progressed, respiration dropped to 20 per minute. The snout, tail and
ezpecially the ears became cyanotic, the animals fell on their side, dying in
that position. Some mice died before reaching such position.
In the mice exposed to ethylmercuric chloride vapor these symptoms devel-
oped over a longer period of time than in the mice exposed to ethylmercuric
phosphate vapor. In similar experiments with metallic mercury such symptoms
did not appear, the clinical picture being one of marked general depression and
slow superficial respiration. The results indicated that vapors of the organic
mercury compounds were more toxic than metallic mercury vapor. Chronic exposure
experiments were performed in 3 especially constructed 50 liter chambers con-
nected with the room air and correspondingly with the sources of ethylmercuric
phosphate, ethylmercuric chloride and metallic mercury vapors; the chambers
were connected with absorbers, flowmeters and a water jet-pump. The air aspi-
rated through the chambers passed first over the respective poisons, then through
the successively connected absorbers with iodine-potassium-iodide solution,
through the flowmeter, and finally, through the suction pump, as shown in Fig.
1. The pump assured a continuous flow of air through the chambers* By varying
the temperature of the air, rate of aspiration and surface of evaporation of
each of the substances tested it was possible to maintain the desired vapor
concentration in the air of the experimental chambers. Average concentrations
of vapors in the chambers in terms of Hg equivalents seres metallic mercury -
0.003 mg/li; ethylmercuric phosphate - 0.00075 ag/li; ethylmercuric chloride -
0.00080 mg/li. Mice were exposed for 6 hours daily, except off-daya.
The clinical picture of chronic poisoning by vapors of organic mercury
compounds was typical. At the beginning of the exposure animals manifested a
state of excitement which lasted 30 to 45 minutes with no other noteworthy
symptoms. Ten to 14 days after exposures were initiated the animals' behavior
changed: they became listless, slept moat of the time, ate poorly, and lost
weight. The symptoms became gradually intensified. The animals ceased to react
to stimulation, moved about sluggishly, and the sense of balance was disturbed.
Paralysis began to spread until the entire posterior half of the body became
involved. When paralysis extended to the front appendages, tonic ^nd occasion-
ally clonic convulsions appeared in response to stimulation and at times spon-
taneously. As intoxication progressed death ensued*
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Fig. 1. Plan of tho setup for the study of the comparative
toxicity of ethylmercuric phosphate, ethylmercuric chloride,
and metallic mercury in chronic inhalation of their vapors
1 - Bthylmercurlc phosphate? 2 - metallic mercury; 3 - ethyl-
mercuric chloride; 4 - exposure chamber Ho. 1; 5 - exposure
chamber Ho. 2; 6 - exposure chamber Wo. 3? 7 - absorbers with
I-KI solution; 8 - flow meters ; 9 — water operated pump
The mice exposed to metallic mercury vapors manifested only changes char-
acteristic of mercurialism: high excitability, loss of weight, slight tremors,
paralysis and occasionally convulsions. The symptoms developed gradually and
were never pronounced* Despite the fact that the average concentration of ner-
cury vapor of 0.003 mg/li was nearly four times as great as in the ex-
periments with ethylmercuric phosphate (0.00075 «MJ/li) aad ethylmercuric chlo-
ride (0.0008 mg/li), the animals in the latter cases died sooner; all animals
died by the 38th day from the start of exposures; animals exposed to metallic
mercury vapcr died by the 58th day from the start of exposure, as shown in
Fig. 2. Thus, the results of the chronic experiments show that organic mercury
vapors were much more toxic than the vapor of metallic mercury.
Conclusions.
1. Inhalation by white mice of vapors of organic mercury compounds, such
as ethylmercuric phosphate and ethylmercuric chloride, caused acute or chronic
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Days from "beginning
exposure.
^ 2 - Comaparative tox-
ioity in chronic inhala-
tion experiments
1 - Mortality curve of mice
exposed to etbylffiercuric
phosphate vapor* 2 - mortal-
ity curve of mice exposed to
ethylmercuric chloride vaporj
3 - mortality curve of mice
exposed to metallic mercury
vapor
poisoning varying in severity with the du-
ration of exposure and vapor concentration*
2. Poisoning by the mercury compounds
followed a definite course and terminated
in the death of the animals. Acute poison-
ing seriously affected respiration and, to
a lesser degree, the nervous system. In
chronic intoxication the central nervous
system was basically affected.
3. Vapors of ethylmercuric phosphate
and chloride proved more toxic than metallic
mercury vapor.
4. The vapor concentration of the two
organic mercury compounds in the workrooms
should not exceed 0.00001 mg/li at the
breathing level.
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The Mechanism of Iron Ore Dust Action on' Animals and Man*
By Tu. I. Leonpva.
Arkhiv Patologii Vol. 20, ffo. 3, 1958, pp. 60-65-
The problem of iron ore dust action on the organism is an important one froa
theoretical and practical viewpoints, since it is still unknown whether sclerotic
lung changes are caused by ferric oxide, hematite being the chief component of
Krivoi Hog iron ore, or by silica duet. Miners working in this area inhale not
only iron ore dust, in which the content of silicon is small, but also the dust
of dead or barren rocks, such as quartaite, horn 6 tone and spilite, which have a
high content of free silica. The solution of this problem is complicated by the
fact that iron ore dust accumulation is impervious to X-rays and simulates lin-
ear and nodular fibre sis on the roentgenogram. (Collis, MacLaughlin, Grout,
Barrie, Harding.) True fibrous nodules are frequently an indication of tuber-
culosis (Stewart and Faulds). Vorwald, Pratt, Pecan, Delahant and Bailey were
able to show that dust from purification of castings composed of ferric oxide
and containing 4% of free silica did not produce fibrous changes in the lungs.
M. M. Vilenskii and I. M. Peisakhovich, and Naeslund were of the opinion that
iron ore dust had no effect on the organism, S. V. Miller, MacLaughlin, Car It on,
Harding, Grout, Lloyd, Davies and Jerry noted that there was no fibrous reaction
from the effect of ferric oxide. Some authors believed that iron ore dust was
not only harmless to the organism, but that in combination with silica dust it
prevented or delayed the development of silicosis (H* M. Demidenko, Kittle, Den-
ny, Robson, Irwin and Naeslund). - .__...._ - -
The purpose of this study was to determine the nature of tissue reaction
to ferric oxide, and to ascertain whether or not iron ore dust containing small
amounts of silica caused lung fibrosis. To simulate dust exposure prevailing
under working conditions, animals were tested by the inhalation method: 30
white rats and 6 dogs were exposed to inhalations of air polluted with iron ore
dust in a cfeastber. The air contained the following: ?e2°* " 92.65#; FeO -
1.4tf I SiO - 5.4&S CaO - 0.122; MgO - 0.03#; PgO- - 0.04*. The ore cane from
the Krivoi Hog mining district. Animals sere exposed daily for 6 hours to air
containing 16,000 - 18,000 dust particles per 1 cm of air, or the equivalent
of 3900 - 4200 mg of dust in 1 m of air. 41.02% of dust particles were up to
1.5 Hf from 1.5 to 2.5 t* - 26.4£; from 2.5 to 5.35 V- - H.8< «* aoove
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Upon completion of the teats animals were sacrificed at different time
periods; m^yttiM"' period of dust inhaling was 16 months for the rats and 24
months for the dogs. The rats were lightly ether narcotised and autopsied and
the dogs were killed by intracardial injection of 5 ol of 4056 formalin solution.
An additional 1? animals were under observation and a group of 15 white rats
were exposed to the effect of quartz dust only.
Specimens of the animals' organs were fixed in a 5£ formalin, passed through
alcohol and embedded in celloidin. Microscopic sections were stained hy hema-
toxylin-eosin according to van Gieson and hy Weigert's method and tested for
iron by Pearl's method; some of the sections were impregnated with silver by
Perdrau's method. In each case histclogic sections were made of the lungs.
Special sections were also made of the lungs, heart, kidneys, liver, hone
narrow, spleen, lymphatic nodes, and cerebral marrow. Particles
of iron ore dust penetrating into the lungs of white rats were phagocytised hy
the so-called "dust cells" which in the early months of experimental exposure
were distributed uniformly throughout the lung tissue and settled chiefly in
the interalveolar spaces. Individual dust cells were found in the alveolar
lumens. The number of "dust cells" gradually increased filling the lumens of
many alveoli forming "dust islands"* Six months after exposure to dust inhala-
tion numerous "dust islands" were uniformly distributed throughout the lung tis-
sue. Simultaneously isolated diffused cells were observed between the alveoli.
The interalveolar walls developed uneven thickening, and thin fuchsinophilio
fibers appeared not only in the dust accumulating areas but also where dust is-
lands were not observed. - Collagenization of the interalveolar spaces was reg-
ularly observed as a result of disturbance of the blood and lymph circulation
in the lungs caused by heavy dust penetration into the lymphatic vessels along
the bronchial and vascular systems. Dust content in the peribronchial and peri-
vascular lymphatic vessels noticeably increased with increase in the time of ex-
posure to dust inhalation. Eight months after the initiation of the teats the
lymph spaces of the paratracheal glands became thickly packed with dust cells.
Disturbance of the lymph circulation in deep lymphatic vessels was accompanied
by an accumulation of dust under the pleura where isolated dust, islands were
situated at the base of the lung in the form of thick chains*
Nine months after exposure to dust inhalation accumulations of lymphoid
cells were observed in spots surrounding dust accumulation foci. An increased
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amount of collagen fibers wag occasionally observed in the interalveolar spaces.
There were also areas of no apparent reaction on the parts of surrounding tis-
sues to deposited dust. Dust cells formed dust islands in spots under the pleu-
ra* The lumens of small "bronchi were filled with dust. The amount of
dust in the peribronchial and peri vascular lymphatic glands considerably In-
creased after 12 months. The collagenization of the interalveolar spaces in
the dust islands and peribronchial and perivascular sclerosis were clearly de-
fined.
Results of the tests indicated that iron ore dust was actively phagocytized
by dust cells densely stored In the lumens of many alveoli and formed dust la-
lands. Surrounding tissue reacted to dust accumulation by slight proliferation
of cellular elements of the interalveolar septi and l?y collagenization of the
interstitial lung tissue. Dust was eliminated by the bronchi and the lymphatic
vessels. Heavily dust laden cells did not lose their mobility. Moving along
the lymphatic channels they filled the sinuses of the local lymphatic nodes.
Weak sclerotic changes apparently were caused by disturbance of the duet-satu-
rated lymphatic and blood circulations in the lungs and not by the solubility
and toxicity of the iron ore dust. Exposure to iron ore dust inhalation over
a period of many months failed to produce cell proliferation and its accompa-
nying development of epithelioid and gigantic multinuclear cells, a cellular ac-
tion which was observed in the control animals subjected to the inhalation of sil-
ica dust only. No coarse coliagenic fiber formation with characteristic distribu-
tion of silicosis centered in the peripheral layers was observed in the dust
islands. Changes similar to the ones described were noted in dogs subjected to
iron ore dust inhalations for 12-24 months. Penetrating into the lungs the
iron ore dust became unevenly distributed in the lung parenchyma as disseminated
foci of dense accumulations of dust cells. The dust islands were distributed
mostly around the bronchi and vessels and contained a large quantity of dust
saturated "dust cells". Occasionally proliferation of uninuclear 3ymphocytic
cells was observed and epithelioid cells were found in spots surrounding the
dust islands. As in the rats, 'coarse coliagenic fibers were absent in the dust
islands. Sclerosis appeared in the form of collagenized interstitial tissue in
the spaces and in the walls of the bronchi and of the blood vessels. In com-
parison with the animals subjected to dust inhalation for a shorter time no
sclerosis advance was observed in animals subjected to dust inhalation for 2
years.
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Dog "Lisa" was subjected to iron ore dust inhalations for 12 months* It
was then sacrificed. Its weight before the experiment was 9 kg and at the end
of the experiment 9.2 kg.
Autopsy report: The lung surface was of a rusty color and the apeces were
emphysematoue; chestnut brown islands were distributed on the background of
lighter colored tissue; thick chainlettes of lead-grey streaks were seen under
the pleura of the lower lobes. Gross tissue sections were moderately plethoric
with scattered chestnut brown islands. The lymphatic nodes at the root of the
lung varied from the size of a pea to that of a beau and were of a chestnut col-
or. The liver was slightly enlarged and plethoric. The kidneys were cyanotic.
Microscopic examination of the lungs: A great number of dust islands sur-
rounding the bronchi and the blood vessels were seen in the arbor alveolaris.
Occasionally dust accumulations filled the lumen of the alveoli and extended as
a thick chain beneath the pleura. A slight lymphoid cell proliferation and oc-
casionally an epithelioid cell proliferation were observed at points of dust
accumulation; fuchsinophilic fibers and deposits of hyaline granules were not
observed. Silver impregnation brought out thick networks of felt-like argyrc-
philic fibers some of which were unenvenly thickened; visible thickening and
increased argyrophilia were noted. Bronchial lumens were enlarged in spots and
contained large quantities of dust cells. Peribronchial and peri vascular scle-
rosis was moderately expressed. The pleura was unevenly thickened and sclerotic
in places* lymphatic gland sinuses near the lung roots were saturated with iron
ore dust (Fig. 2). An even granular dystrophy and moderate interstitial scle-
rosis in the supporting connective tissue.were seen in the parenohymatous or-
gans. --.-._.
Conclusion: One year after the completion of the experiments multiple dust
islands were observed in the lungs predominantly around the bronchi and the blood
vessels, underneath the pleura and to a lesser degree in the alveolar lumens*
The surrounding tissue reaction was manifested as a slight proliferation of
lymphoid and epithelioid cells. Silver impregnation brought out a thick network
of argyrophilic fibers in the areas of dust accumulation. Peribronchial and
perivascular sclerosis was moderately expressed. Dog "Dvoinik"1, exposed to inha-
lations of iron ore dust for 1.5 years, developed extensive dust accumulation
which filled the pulmonary lymphatic network, the lymphatic vessels of the pleu-
ra and the lumens of a considerable number of alveoli. (Fig* 3). Collageni-
zation of the interalveolar spaces and perivascular sclerosis developed at the
-------
spots of "dust islands" concentration. Dog "Zhitaya" was killed 2 years after
exposure to dust inhalation. Pooi of multiple dust accumulation were absent}
cell proliferation and sclerosis were almost completely absent in spots. Pres-
ence of dust along the lymphatic channels of the pleura, the mediastinum, the
diaphragm and the epicardium were clearly discernible* (Fig. 4).
Iron'ore dust was phagocytized not only by "lung phagocytes" but also by
liver copper cells, the reticular and endothelial cells of the spleen and of
the lymphatic glands. Dog "Belka" was sacrificed at the same time. In addition
to the changes described above, tissue examination showed large dust accumula-
tion in the central and interfollicular sinuses of the lymphatic glands and of
the lymphatic glands lying along the greater curvature of the stomach. Compar-
ison of results observed in rats exposed to iron ore dust inhalations with
results seen in dogs showed that in the case of dogs the dust was chiefly elim-
inated via the lymphatic system. Dust cells settled in the peribronchial and
perivascular lymphatic spaces and accumulated densely in the lymphatic network
of the pleura and in its connected lymphatic follicles. Large iron ore dust
accumulation was found in the lymphatic channels of the epicardium and the di-
aphragm, and outside of the thoracic cavity - in the periportal and mesenteric
lymphatic glands of the greater stomach curvature.
Histologic examination was made of the tissues of a dead Krivoi Rog miner.
Results are described below for comparison with the results of animal tissue
examinations. Worker L. aged 22 years, died in an accident, after working in
a mine underground for 3 years and 4 months. According to the information re-
ceived from his place of work the content of silicon in the mine air was 10#,
and of iron 40 - 46%.
Microscopic examinationi The tissue of tae upper lobes of the lungs was
of an uneven pneumatic type. Areas of distended emphysematous alveoli alter-
nated with small areas of lung collapse and with greatly thickened interalveo-
lar septi which showed cell proliferation and plethoric capillaries. Against
this background a few dust densities were evenly disseminated throughout the lung.
The dust islands were round or oval-shaped and consisted of many dust cells
thickly distributed within the lumens of the alveoli* The interalveolar septi
wore thinner than usual and appeared as thin layers or as separated "dust cell"
groups saturated with dust. Proliferation of uninuclear lymphocytic cells de-
veloped at points of marl mum dust accumulation. A slight sclerosis in the form
of a light collagenization of the interalveolar spaces was clearly observed*
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Blood vessels were dilated, plethoric and surrounded by clusters of dust cells.
Separate dust cells and cell clusters were seen in the mucus of the bronchial
lumens} they contained less dust than the "dust island" cells. There were also
free "dust cells" lying in the mucus of some of the alveoli and of the bronchi
(desquamatiye alveolitis). Practically no dust'cells were seen in the inter-
alveolar septi and under the pleura. Other sections taken from the lungs showed
a few dust accumulation foci which like the upper lobes had distinct outlines
and consisted of "dust cells'* which filled the interalveolar spaces. Clusters
of cells filled with dark chestnut dust were present near the blood vessels.
Moderate perivascular and peribronchial sclerosis was present. The lung tis-
sue of the lower lobes was of an even pneumatic type. Dust accumulations were
few. Reaction to iron: "dust cells11 forming islands acquired dark blue, al-
most black color* The few "dust cells" present in the interalveolar spaces ap-
peared light blue, against which the dark chestnut dust particles were clearly
seen. A light blue color was observed in areas free from the lung parenchyma.
The distribution of dust in the lungs of this man differed somewhat from
the distribution in animal lungs. Mft-riimim accumulation was in the lumens of
the alveoli. "Bust islands11 were large and clearly delineated against the back-
ground of the lung tissue. Relatively little dust was found in the interalveo-
lar septi and its accumulation under the pleura was practically absent.
Iron ore dust elimination occurred principally through the bronchi* In the
lungs of man, as in the lungs of the experimental animals, active phagocytosis
of iron ore dust aggregation and formation of dust islands were in evidence.
Surrounding tissues reacted to iron ore dust by cell proliferation in the inter-
alveolar spaces (septi). Sclerosis of the lungs was not manifested; it can be
assumed, therefore, that lung tissue reacted to iron ore dust in one way only*
Iron ore dust in combination with small amounts of silicon produced sclerotic
nodules and possessed no toxic properties.
Summary.
1. Iron ore dust which found its way into the upper parts of the respira-
tory tract was phagocytized by the so-called "dust cells11 which form "dust cell
islands'*. Iron ore dust was eliminated via the bronchi and the lymphatic chan-
nels.
-216-
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•
-
- i
'•1.1- - . - .
m
2. Gradual lung saturation with iron ore dust resulted in the voluminous
• -
accumulation of the dust in the paribronchial and perivascular lymphatic spaces
•
and in the lymphatic channels under the pleura*
3. In chronic cases of exposure to iron ore dust inhalation there devel-
oped a blockade of the pulmonary lymphatic channels and of the pleura; along
with this there was an accumulation of the dust in the lymphatic vessels of
the mediastenum, epicardium and diaphragm; large dust accumulations occurred
in the local lymph nodes and also in the lymph nodes situated beyond the lim-
its of the thoracic cavity (mesenteric, peribronchial , cervical and minor stom-
ach curvature).
+
4* Disturbance of dust-saturated lymph and blood circulation was accom-
panied by a disturbance in the oxidation-reduction system, a reduction in the
respiratory lung area and by an accumulation of products of tissue metabolism;
in totality these deviations from the physiological normal appeared as the
probable cause of interstitial sclerosis; this assumption is supported by the
•
fact that iron ore dust per ee possessed no toxic properties.
Formation of sclerotic nodes which are characteristic of sclerosis
were not observed in pure sidereal*.
i
6* As a rule, under working mining conditions, miners inhaled not only
iron ore dust, but also "dead" rock dust; accordingly, changes occurring in the
4
lungs must be classed as symptoms of sinderc— silicosis.
Pig. 1. Argyrophilic fibers in a
dust islet. (Perdrau silver ira -
pregnation. High magnification.
-217-
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.
' •
,_ • • • -
-- . • •
Pig. 2. Dust cell accumulation in
the sinuses of the lymphatic node
Ferle*s stain* High magnification
Fig. 3. Iron ore dust deposition
neath the pleura, van Cieson stain
High magnification
' *
^jpr^at-
'.-aUS*.
Fig. 4. Dust accumulation in the lymphatic and
vessels, van Gieson stain. Magn. X 30
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The Study of Bacterial Air Pollution.
V. A. Zubarev.
Irom the Ctesk, M. I. Kalinin Hedical Institute.
Cigiena i Sanitariya, No. 7, 35-36, 1954.
Existing apparatus and equipment for the determination of the bacterial
content in the air are complicated and expensive. This limits their utility
and makes them available only to large and well-equipped laboratories; the
size and complexity of such equipment prevents it from being used widely in
sanitary-hygienic control work and similar objectives. Such equipment is
based chiefly on the centrifugal principle and recovers only large particles
and droplets with bacteria adsorbed to them while individually air suspended
bacteria are brought down only in part. And yet it is the individually sus-
pended bacteria that are of greater significance epidemiologlcally.
The apparatus herein described is comparatively free of such defects. It
was designed to enable the sanitary doctor to deteucine with greater accuracy
the degree of bacterial distribution in the air of an investigated enclosure.
The apparatus is simple and can be made in any mechanical shop* It is schemat-
ically presented in the accompanying drawing.
Hygroscopic cotton,
as filtering material,
is placed into a metal-
lic tubular adapter
100 - 150 mm in length.
The cotton layer is
held in place by a wire
gauze and by 2 - 3 fast-
eners. In taking air
samples, the tube with
. - Plunger; 2 - valve, 3 - compression ringsi 4 - the cotton filter is
valve, 5 - nipple fo the attachment of the sample securely attached to a
collector, 6 - rubber tubing, 7 - an opening, 8 -
plunger stop-piece, 9 - rubber washer* 10 - rtppl* hand **r *•*• The *«*"
nut, 11 - tubular sample collector, 12 - cotton ter is equipped with
plug, 13 - cotton plug holders
- 1Q6*K -
ft
Schematic drawing of the device for the determina-
tion of bacterial air content
-------
•two rubber valves (2 and 4), one of them being attached to the inner end of
the pump nozzle and the other to the plunger. The plunger (l) is provided
with two compression rings (3). The capacity of the pump should be in excess
of 1 liter. Then with the help of a dowel pin (8) the inflowing air volume
is limited to 1 liter as indicated by a flowmeter* The calibration of the ap-
paratus must be done with the loaded adapter attached to it. Prior to taking
the air samples, the needed number of cotton filled adapters are wrapped in
paper and sterilized. Control tests showed the bacterial air sample collection
was free from undesirable leakage at an aspiration rate of 2.5 * 2.8 m/sec and
pressure drop of 3 - 5 mm of water column. At the sample collecting point the
adapter is attached to the pump and the required quantity of air aspirated*
The rate at which the pump plunger is drawn can be controlled by calibration
marks $ this a ill determine how much of the air was aspirated at any moment of
sample collection; an ordinary bicycle tachometer can be used for this purpose.
As in surgical operations, proper precautions should be observed to prevent
the tested air from becoming eztraneously contaminated.
When the air sample collection is completed, the cotton filter is removed
from the adapter with sterile pincers and placed into a sterile flask contain-
ing 50 - 60 ml of distilled physiological saline; the flask is vigorously shaken
for 2-3 minutes and the content poured into a funnal containing a membrane
filter. The cotton filter is squeezed with the pincers, and washed with saline
3-4 times and the wash saline passed through the membrane filter or through
new ones if so required. Experience indicated that evan in the case of lightly
contaminated air it is best to use two membrane filters*
The second stage of analysis, the washing of the cotton filters, is a
painstaking and difficult step in this method.
The method for cultivation of colonies is the usual one. The choice of
culture medium is determined by the special study requirements*
Control tests made in the Bacteriological Laboratory of the Omsk Oblast
Sanitary-Epidsmiological Station showed the following:
1. The cotton filter retained all the bacteria contained in the aspirated
air*
2* In washing the cotton filter with three successive portions of physi-
ological solution 96 - 9&% of the retained microorganisms were freed. Results
of parallel studies with the proposed and the Shafir apparatus showed that the
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-------
latter retained 70 - 60£ of the air "bacteria as against 100£ retained by the
proposed apparatus.
3. 'The time elapsed between taking the sample and placing the membrane
filter on the culture medium had no effect on the number of viable colonies*
Studies of Airborne Hicroflora.
37
V. V. Vlodavets.
From the Institute of General and Communal Hygiene, Academy of Medical
Sciences, U.S.S.R., Moscow.
Lab. Del., Vol. 3, Ho. 1, 41-43, 1957.
The Institute of General and Communal Hygiene has been receiving frequent
requests related to methods for the study of airborne microflora. The purpose
of the present report is to describe certain situations with which bacteriolo-
gists are faced in bacteriological air analysis.
The degree of atmospheric or enclosed air contamination with bacteria is
expressed in the number of viable microorganisms per cubic meter, as shown by
the number of colonies developed on meat-infusion agar during 24 - 48 hours
incubation at 37 * For this purpose any volume of air can be aspirated and
the final results expressed in terns of numbers per m .
However, there are many reasons for which the abovo bacteriological pro-
cedure falls short of presenting the complete picture of the microflora air
content. It is well known that different apparatus used in bacterial air analy-
sis yield different counts, and that none of the existing apparatus caught 100
percent of the air bacteria. This may be due in part to the difference in the
degree of bacterial p&rticulate dispersion. The best apparatus for the study
of air bacteria at the present time are the Hemchenekii bacteria collector and
the Krotov apparatus. The nutrient medium on which the airborne bacteria are
cultivated is a factor of prime importance; thus, many of the airborne bacteria
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-------
fail to develop colonies visible even with a magnifying glass in beef-infusion
agar after 24-48 hours incubation at 3? . Under the above conditions aneroblc
bacteria can not develop since they require partially reduced oxygen tension;
streptococci will not develop on beef-infuaion agar in the absence of blcod
and sugar; fungi will develop poorly, and yeast and actinomyces need special
' media at a lower temperature, which is equally true of psychrophilic micro-
organisms present in the air. Special methods must be employed for the iso-
lation of filterable virus from the air. Usually, after 24 to 48 hours incu-
bation in a dark incubator the pigmentation of airborne cocci is not distinct.
* It can be seen from the above that the number of viable microorganisms
in a given volume of air as determined by cultivation on one medium and at
one temperature of incubation for a specified time is a relative value at best.
In comparative air bacteriological studies of a limited scope and having in
view a specific purpose the use of a single strictly defined procedure may have
Its value.
According to data presented in the literature, the greatest number of air-
borne microorganisms develop colonies on beef-infusion agar or sugar agar upon
4 to 5 days incubation at 20 to 22 . Under such culture conditions colonies
become well formed and the pigmentation is distinct. Well developed pigmented
colonies will also develop in 48 hours at 37 » or at room temperature, but
the bacterial count will be materially reduced*
Air analysis for pathogenic microorganisms necessitates the use of selec-
tive media, as for instance, in the case of hemolytic strepto and staphylococci
which grow best on blood agar. A good selective medium for streptococci is the
Garra medium, and for Corynebacterium dlphtrlae, the tellurite medium, for
Hemophilias pertussis, the Bordet-Cengau medium.. The use of selective media
makes possible the isolation of pathogenic bacteria from air heavily contami-
nated by saprophytes.
Bacterial inoculations for plate counts should be made with discretion)
plates should be seeded evenly and neither too sparsely nor too heavily, if
they are to produce statistically reliable counts. The bacterial mi cr of lor a
of atmospheric and enclosed air consist of many species of microorganisms -
which form different types of colonies. For instance, while the airborne cocci
form small, sharply defined colonies, the gram-positive sporebearing rod-shaped
bacteria develop large and medium-sized spreader colonies, especially if moisture
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is allowed to accumulate over the surface of the medium. Therefore, Petri
dishes containing the medium should be veil dried by incubating them with
their lids down for several hours before incubation to preclude the spreading
development of the gram-positive rod-shaped bacteria.
Cultured airborne mioroflora can be studied best if the number of colonies
per Fetri dish averaging 9 cm in diameter does not ezceed 250. Optimal condi-
tions for the study of the characteristics of the microflora are obtained when
the developed colonies range between 50 and 150 per dish. When the number of
colonies per dish ezceed 300, determination of the microflora becomes diffi-
cult, because some large colonies crowd out or grow over other colonies and
in some cases inhibit their development* For instance* many gram-positive
sporebsaring rod-shaped bacteria produce potent antibiotic substances which
retard the development of the airborne cocci. The largest number of colonies
that can possibly be counted on a Petri dish may vary from 1200 to 1800; how-
ever, in such cases the counts can not be statistically reliable and colony
and individual bacterial characteristics can not be well defined. It should
be noted that where colonies ezceed 250* or even 200 per plate, it is diffi-
cult to observe staphilococcal hemolysis; it becomes particularly difficult
to study the streptococci on blood agar under crowded conditions. This is
particularly true in the presence of airborne sporeforaiers which possess strong
hemolitic activity.
Overcrowding of plates can be avoided ty inoculating the plates in series
of diminishing air volumes established by a rapid preliminary count study of
the bacterial air condition. It is better to run tests in duplicates, even
triplicates, wherever and whenever possible, on the principle of the above
mentioned series. If the analysis is made with the aid of the Krotov apparatus,
provisional volumes of 50 to 100 li should be aspirated in cases of low bacte-
rial air contentj 25 to 40 11 if bacterial content is medium, and 10 to 20 li
if it is high. Where the Dyakonov apparatus or the Remchenskii bacteria col-
lector is used, and the bacteria are transferred from a liquid into a solid
medium, consideration should bo given to the fact that transfer of some of the
liquid medium may facilitate the spreading development of the gram-positive
red-shaped bacteria; in such cases 25 to 50 colonies per plate should be the
limit.
Effort should be ezerted to hold the number of colonies per dish within
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the limit of 100. Best results may be obtained by inoculating small quantities
of the liquid, such as 0.1 to 0.01 ml, on a moisture-free medium surface and
calculate the number of colonies on an addition or average basis. The inocu-
lated liquid should be well spread with a sterile L-shaped glass rod distrib-
Luting the inoculation evenly over the surface of the dish. Where counts are
expected to be low air samples of 100 to 150 11 should be obtained by means
of the Remchenskii bacteria collector, and 50 li of air should be taken where
counts are expected to be high.
„ The study of bacterial aerosols artificially created in special chambers
for the investigation of the properties of air-suspended bacteria as well as
for the study of the effectiveness of various bactericides necessitates a dif-
ferent approach. At the present time, white and aureus staphilococci, the
colonies of which are comparatively small, are used most frequently in experi-
mental studies. In such instances the inoculation of hard media presents no
special problem because of the homogeneity of the bacterial population; a count
of 2000, 3000 and even 4000 colonies presents no problem. Difficulties may
arise if the number of colonies exceed 4000*
The quantitative and qualitative aspects of airborne microflora remain
largely unknown* Many problems related to bacterial air pollution need to be
studied specifically and in greater detail. Until more basic information will
have been accumulated, there will be no basis for arriving at air purity which
must take into account climatic, meteorological and other extraneous factors.
However, for special rooms, such as operating rooms, blood transfusion rooms,
rooms for bottling sterile Pharmaceuticals, immunological preparations, etc.,
where the airborne bacteria should be at a minimum, standards for bacterial
air purity can and should be evolved and proposed in the near future.
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Three Conferences on Combatting Pollution of Atmospheric
Air of Inhabited Localities.
(A report).
Gigiena i bunitariya, No, 12, 1954, pp. 48-50.
Three conferences were held recently covering air pollution problems on
a broad basis. Among the participants were representatives of technological
scientific-research institutes, of industrial ministries, of the Ministry of
Health of the U. S. S. R,; of hygienic institutes, and representatives of such
industries as Electric Heat and Power Centers„ (TEC). Problems were discussed
pertaining to the combat cf atmospheric air pollution of inhabited areas by
industrial production and manufacturing discharges. The conference evoked con-
siderable interest in the scientific-technological phases announced in the pro-
gram and drew^ a large attendance.
The scope of subjects discussed by the Checacal Section of the Committee
on Coordination of Scientific-Research in the Field of Purification cf Indus-
trial Discharges into the Atmosphere was broadened; the Coordination Committee
worked in cooperation with the Ministry of Health and with the Ministry of the
Chemical Industry of the U. S. S. R. The basic problems discussed dealt with
the purification of smokestack gases from S0_. The conference met at the In-
stitute of the Nitrogen Industry in Moscow on 14-15/X» 1953*
The Committee on Coordination resolved:. In the light of the resolutions
adopted by the September Plenum of the CC (Central Committee) of the CPS3 (Com-
munist Party of the Soviet Union) the problem of purification of discharge gases
from SQp and its utilization became most urgent; a definite time limit was set
for the solution of the problem. Various Committee members felt that the Min-
istries of the Chemical Industry, the Nonferrous Metallurgical Industry, the
Electric-Stations, and of the General Electric Industry failed to give this most
important problem of national economy the .consideration it deserved. Many meth-
ods have been proposed for the purification of discharge gases from S0_; but to
date only three methods were being applied on a practical industrial scale; the
acid-ammonia method, the cyclical-ammonia method, and the lime method. The othe:
methods have not emerged from the experimental stage, or the stage of laboratory
application.
It was pointed out in the resolution that all gases which contained S0? in
concentrations up to 3$ should be mandatorily reduced to the norms prescribed
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by the Ministry of Health of the U. S. S. R.; gases which, contained SO^ in
concentrations of 3£ or more should be utilized on a must basis for the di-
rect production of ELSO* by the usual method; gases which contained SO- in
concentrations of 1 - 3£ in the majority of instances should also be utilised
for the production of H-SO. after preliminary- concentration; where need ex-
isted to obtain liquid sulfurous anhydride such gases should be concentrated
to 10056 SOp. In the non-cyclical oethods of trapping sulfurous anhydride
along with the purification of the gases, it may prove purposeful to simulta-
neously recover such valuable chemical products as SO., elemental sulfur,
fertilizer compounds, etc. In special cases, the purification process of dis-
charge gas of sulfurous anhydride could be paralleled by the processing or by
the utiliaation of local raw products, such as nephiline, zinc oxide, magne-
site, limey manganese, etc. Such procedures and methods should be given pref-
erence ovor methods which require transportation of raw products from afar;
It was noted in the resolution that of the methods which have passed the
test of practical industrial application the acid-ammonia method for purifica-
tion of discharge gases from S0_ could be recommended for use in any SO- con*
centration, where the reserve of ammonia was adequate and where the need for
(NH,)?SO. assured the utilization of this by-product* Experience with the
cyclical-ammonia method for the purification of discharge gases from S02 in
one of the largest TEC (thermo-electric centers) of the liosenerg (Moscow Sa-
ergy) lead to the conclusion that this method was applicable to the purifica-
tion of gases discharged by electro-station smokestacks as well as to the trap-
ping .of. the much more highly.-concentrated 50- in discharge gases emitted by
smokestacks of the non-ferrous industry. It was noted, however, that in this
connection the. cyclical method needed to "be improved with respect to more
effective cooling of the return-water*' With respect to the lime method, the
Coordination Committee noted that it had reached an adequate stage of develop-
ment, but was complicated by the rapidly accumulating residue which created the
removal problem except where it could be used in the manufacture of construction
material. Resolutions were adopted stressing the need for the creation of ex-
perimental centers in the many plants operated by the Ministry of Electro-
Stations, the Ministry of the Chemical Industry, and the Ministry of the Non-
Ferrous Metallurgical Industry, where the many proposed methods for the purifi-
cation of industrial discharge gases from SO- could be tested on a practical
industrial scale, such for instance as the zinc method, the oxychromic method,
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the magnesite method, the autoclave-ammonia method, etc.
Another conference, held under the auspices (also) of the Committee on
Coordination of Scientific Research Projects, related to the purification of
industrial discharges into the atmosphere, was devoted to the discussion of
methods for the determination of duet density in industrial discharge gases
and the degree of dust dispersion (aerosol). The scope covered by this con-
ference Has also considerably broadened and more extensive than in the past.
The conference met in the Institute of the Nitrogen Industry 24-25/V, 1954.
The conference authorized the Committee on Coordination of Scientific Research
Studies (in the field of purification of industrial discharges into the atmos-
phere) to coordinate, unify, and standardize the methods for the study of dust
density in industrial discharge gases and for the determination of the disper-
sion-composition of the suspended dust.
It was noted in the resolutions of th& Conference that the gravimetric
method was most widely used for the determination of the dust content of dis-
charge gases. As compared with other methods, the gravimetric method was re-
garded as the control method and as the method most universally applicable to
all types of suspended dust. However, it had its shortcomings, the complex
apparatus required, technical difficulties, etc. The optical method of dust
determination possessed the possibilities of uninterrupted control in dust
trapping installations; however, it was badly in need of further improvement
so far as the determination of the suspended particles were concerned; also,
the equipment called for improvement and better adaptation for use as a control
method under practical industrial conditions. The count method could be used
best in the sanitary-hygienic evaluation of the air medium in low dust concen-
trations with particles not exceeding 1O p (the editors of Gigiena i Sanitariya
questioned the latter assertion). The Owen counter possesed certain shortconh-
ings and was not recommended "by the conference for use in dust density deter-
minations. In low dust concentrations, the.methods of thermal or electro-
static precipitation were regarded as feasible* The method of continuous ul-
tramicroscopy of Deryagin-Vlasenko enabled particle size determination in the
air current; it was less cumbersome, and could be recommended for adoption under
industrial conditions in the determination of the degree of dust retention by
gases after they have passed through an electro-static precipitator. The con-
ference felt that the continuous ultramicxoscopic method for gas duet content
determination should first be perfected to the point where the subjective visual
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count could "be replaced by an automatic count-recording apparatus.
Many methods have been developed for the determination of content of
vi
dispersed industrial dusts. At the present time the following found wide
acceptance: a) Screen analysis applicable where dust particles measured more
than 45 - 60 p; b) The method of air separation which differentiated parti-
cles exceeding 3 - 6 }i in diameter; c) Sedimentation analysis which enabled
the measuring of suspended particles 1 ^ or more in diameter. The lack of a
single standardized method for the determination of dust content in industrial
discharge ^ases and the dispersion composition of the dust, resulted in the use
of non-standard apparatus and equipment, frequently made by inexpert workers,
which in turn produced non-comparable analytical results. Therefore, the con-
ference urged the early development and standardization of quantitative and
qualitative dust determining apparatus which should be produced and regis-
tered by serial numbers.
In 1954j the Energy Institute of the Academy of Sciences of the U. S. S. H,
and the All-Union Scientific Society of Technical Energy Engineers called into
conference a scientific-technical session to discuss the problem of future
provision of cities with heat. The conference met in Leningrad in 9-12/VI,
1954 in the large hall of the Academy of Sciences of the U. S. S. R. Sixteen
reports were presented.
The reports and discussions related to future provision of cities with
heat indicated that the work reached a new stage of_ development in the
Soviet city heat supply which called for new and more progressive technical-
economic means for proper compliance with resolutions adopted at the XIX Con-
gress of the CP3S (Communist Party of the Soviet Union) regarding the more
extensive introduction of central heat supply centers in cities and in indus-
trial regions. The advances made by the Soviet Heat-Energy Industry brought
the problem into the realm of possible realization by way of more distant (20 -
40 km) transmission of the heat produced by the TEC (Thermo—Electric Centers)
which burned low grade, hard fuel. Even more progressive and promising than
the preceding was the principle of complex chemo-power utilization of fuel
based on a new method developed in the U. S, S. R. for obtaining higii calory
combustion gases and. a large volume of valuable chemical by-products. This
made possible the conversion of TEC (Thermo-Electric Centers) to operation by
gas, completely freeing the atmosphere from pollution with harmful combustion
products, and making possible the transmission of heat to large cities located
•
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150 - 200 km from the TEC. In providing heat and power to distant points this
development also affected favorably certain agricultural enterprises, such
as truck gardening, thereby assuring the nearby cities a supply of fresh vege-
tables through the year.
The Session Resolutions also emphasized that among the problems
requiring immediate attention and realization was the development of econoudc
plans and pertinent provision for the construction of surburban ?SCs. In this
connection it was equally emphatically stressed that in the construction of
such suburban TECs sight should not be lost of the need for sanitary-hygienic
installations and other provisions to protect the atmospheric air from possi-
ble pollution by the TEC smokestack discharges.
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Conference on Problems of Bust Catching.
By N. P. Pitelin.
Glgiena i Sanitariya, 1955> Ho. 12, p. 47.
A conference on problems of dust catching sponsored by the Committee on
Coordination of Scientific Research in the field of purification of industrial
emission took place in Moscow on March 22 - 24, 1953* Among the participants
were representatives of 74 organizations from Moscow, Leningrad, Kiev, Kazan,
and other cities* Sixteen reports were presented and 26 scientists spoke.
All agreed that regardless of the considerable volume of work done cooper-
atively by physicians and engineers on the elimination of dust discharges into
the atmosphere, only a partial dust abatement has been attained in some Indus—
trial areas (e.g. Kemerovsk hydro-electric station)* The state of affairs with
regard to dust pollution elimination presented a disappointing picture. Atten-
tion was called to industrial enterprises which operated without dust-catching
equipment. It was also brought out that in plants equipped with gas-purifying
installations the desired dust-catching efficiency has not been attained because
the installations had been incorrectly assembled, or they were unsatisfactorily
operated for lack of qualified and technically trained personnel* No provision
existed for continuous technical control of the effectiveness of the dust-catch-
ing operation*
Some responsible departments failed to cooperate with the Scientific-Re-
search Institute for Sanitary Purification of Industrial Discharge Gases by not
opening to members of the Institute working areas and not having adequate num-
bers of qualified personnel, despite the fact that this Institute is the leader
in the field of research on dust-catching devices. The Ministry of ^on-Ferrous
Metallurgy and the Ministry of Building Materials had developed no methods for
the recovery of valuable ra& materials discharged into the atmosphere* The
Ministry of Higher Education provided no qualified trained specialists in dust-
catching and gas-purification ?ho could be assigned to special scientific re-
search institutes or industrial plants which were equipped with gas-purification
installations. The Ministry of !Iachin© and Apparatus Building was delinquent
in providing a continuous supply of controlling and measuring apparatus neces-
sary for the determination of atmospheric gas and dust concentrations and of
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automatic devices for the operating control of the dust-catching installations.
The U. S. S. R. "Goeplan" failed to include into the national economy plan pro-
vision for the construction of facilities and for the equipping of plants with
automatic gas-purifying installations.
It was brought out during the conference that the amount of scientific re-
search done in the field of dust-catching was sadly inadequate. The Ministries
failed to approve many projects which were to have been assigned to specialized
institutes in this field. Experience gained in using existing dust-catching
installations was not being published and, as a consequence, the results could
not be analyzed or evaluated. Papers were presented describing basic features
of dust-catchers of different designs. The following were approved as having
future possibilities: net type cylindrical or tubular dust catcher in combina-
tion with VTI scrubber? foam dust-catcher of IOT design? centrifugal purifiers
for highly dispersed dusts.
The Conference found the following promising but requiring checking under
experimental production conditions: the centrifugal dust catcher of TsRP de-
sign for fine dusts and aerosols; wet scrubber of HOT design for the purifica-
tion of ventilation air; condensation scrubbers of the Krivoroshskii Scientific
Research Mine-Exploring Institute in which aggregated particles are formed by
way of condensation.
•The Conferences recommended that work be continued on the application of
ultrasonics to the field of industrial emission-gas purification principles and
methods of dust catching, more perfect and more economical than the existing
ones. The need to develop methods for the removal of accumulated ash and other
partlculate matter was discussed aa a problem of urgent importance. It was •
pointed out that present methods of accumulated ash transportation and dis-
posal in open dumps in themselves created problems of air pollution.
The Conference unanimously agreed that the various Ministries failed to
give the required serious attention to their basic responsibilities in the field
of atmospheric air purification from industrial discharges of noxious gases,
fly ash and other particulate matter.
The need to develop automatically operating dust-gas-catching processes
and methods of their control was emphasized*
. Some members of the Conference urgently recommended that a collective dis-
cussion be organized in the noar future to consider ash-catching and ash-remov-
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lug processes and installations for small and medium boiler-operated plants as
well as the problems of disposal and utilisation of emission purification prod-
ucts accumulated as a result of existing air pollution aoatsment devices*
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All-Union Conference on Problems of Air Hygiene, Water
Hygiene and Sanitary Bacteriology.
M. S. Goldberg, K. S. Kovarskii, L. I. Mats, N. A. Ruffel.
Gigiena i Sanitariya, 1955» No. 12, p. 45.
On May 16 - 20 an Ail-Union Conference was held in Moscow which dealt
with problems of air hygiene, water sanitation and, sanitary bacteriology.
The conference was sponsored by the Institute of General and Community Hygiene
of the Academy of Medical Sciences (AHN) U. 5. 3. R. ; among the participants
were representatives from institutes of danitary-hygiene, departments of hy-
giene of medical institutes, national sanitary inspectors and head physicians
of sanitary-epidemiological stations.
The Conference heard and discussed 90 reports and papers by hygienists
and sanitary physicians. Plans were outlined for progressive research devel-
opment in the field of hygiene and for the application of results to practi-
cal public health problems in the .U. S. S. R. It was pointed out, that dur-
ing the preceding 20 years, many diversified studies were made on problems
related to the preservation of air purity; the results were applied in prac-
tice and served as a basis* for the enactment of Soviet sanitary laws. An out*
standing trend in the development of Soviet air hygiene was the consideration
given to the significance of intereffect between the living organism and en-
vironmental factors, pointing to the need of studying the two simultaneously
as interconnected parallel phenomena. - .
Reports presented at the Conference indicated that during .
1948 - 1954 over 2000 gas purifiers were built for the recovery of industrial
waste products at electric power stations and production plants* The need
for more gas purifying equipment was emphasized* Attention was also called
to the fact that many gas purifying installations operated at low efficiency.
Reports showed that the sanitary~hygienic state of atmospheric air of
many inhabited areas was >>elow the recommended standards. The conferees
stressed the need of more intents development in that direction. Sanitary-
epidemiological stations of large cities and industrial centers were urged
to institute a system of constant laboratory control over factors contribut-
ing to air pollution. . .
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Reports on the hygienic evaluation of the air in industrial areas and
on the effect of pollutants on the population's health were of high .quality
and were based on statistical morbidity studies, on related clinical group
examinations, on. experimental animal exposures under actual conditions, on
studies of functional changes in the central nervous system, etc. Reports
on examination of air inside living quarters, in areas close to industrial
emissions, "brought out important practical information. This caused the Con-
ference to include such research into programs of scientific studies of air
pollution, especially with reference to carbon monoxide and sulfur dioxide.
With regard to suspended particulate impurities in the air it was recommended
that atmospheric pollutants be studied thoroughly, quantitatively and quali-
tatively, including degree of dispersion, chemical composition of dust, par-
ticularly the content of free silicon dioxide, etc.
The presence in the air of carcinogenic substances presented a complex
problem requiring extensive and properly planned research along the following
linesi a) study of the .nature and degree of air pollution with cancerogenic
substances in large cities and industrial centers in relation to type of fuel,
method of combustion, meteorological factors and miscellaneous local condi-
tions; b) study of morbidity according to age groups in areas of various de-
grees of air pollution with cancerogenic substances arid in control areas hav-
ing pure air; c) animal experiments to determine the importance of air as a
factor in the, etiology of cancer. Realization of this program requires co-
operation between hygienic and clinical research institutes, such as the In-
stitute of Oncology,-AMN U. S» S. R,, local oncological clinics?, etc. -
Attention was directed to lack of cooperation between institutes of hy-
giene and clinical and therapeutic-prophylactic institutes. The Conference
mentioned the valuable work carried out by the Rostov University Physics De-
partment in the construction of new apparatus for use in air hygiene, such as
the laboratory and field models of the Cottrell electrostatic precipitators.
It was suggested that such equipment be approved without delay. Attention of
.scientific research institutes of hygiene and of university departments of hy-
giene was called to the urgent need for developing rapid methods to be used
in the determination of air gas pollution and to the adoption of new methods
for quantitative and qualitative studies of ai^suspended particulates and
aerosols by methods of separation and under existing conditions of dispersion,
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which involve electrostatic precipitation, thermo-^recipitation, continuous
ultra-microscopy by the Deryagin-Tlasenko apparatus, eto.
The Conference discussed problems of rural water supply, sanitary pro-
tection of water sheds, disposal of industrial wastes and maximum permissible
concentrations of harmful substances discharged with waste waters.
The Conference discussed general sanitary-hygienic problems related to
specific rural water supplies, state of motor traction stations, sovkhoz"
and kolkhoz water supply, and generally used and commonly recommended methods
of purification, decontamination and clarification of drinking water. The
desirability of early extension of water supply lines to KTS (motor traction
stations) and sovkhozes was also discussed. It was pointed out that communal
wells, small water reservoirs, excavation reservoirs and irrigation ditches
are still widely used ss sources of drinking water.
Attention was called to the need to study projects dealing with the stand-
ardization of mineral (salt) content of drinking water. The Conference rec-
ommended specifically that studies be made on the extent of brackish water
used on farms for drinking purposes paralleled by studies of the state of the
population's health in relation to the chemical composition of the water.
Considerable time was given to the discussion of the possible delay in
the Tsimlyanskii reservoir project caused by inadequate preparation of the
river bed before flooding; the Conference stressed the need of a systematic
year-round preparedness to protect the entire stretch of the river bed.
Reports presented before the Conference on reservoirs presently being
built on Angora, Dnieper, in Stalingrad, and Novosibirsk, brought, up new prob-
lems in planning sanitary measures for future watersheds and supplies related
to local, natural and hydraulogical conditions. Mention was made of the cor-
rect integrated sanitary approach used by the Ukrainian Institute of Community
Hygiene in attacking the entire Dnieper basin problem at one tirre and not on
a piecemeal basis.
The Conference recommended that sanitary regulation be adopted for the
sanitary protection of completed reservoir sections and for the prevention
of cave-ins.
Some reports indicated that, on the basis of some positive experience,
rules we e enacted for sewage dilution, and sanitary regulations were adopted
controlling the discharge of waste waters into streams and running lakes. Re-
sults of some reports established the potent effect of suspended matter depos-
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ited at outlets, near snail bays, etc., on the processes of dilution and self*
purification of waste waters. The Conference recommended that data on water-
shed studies be interpreted as suggested by the Institute of General and Pub-
lic Hygiene of AID* U. S. S. R. (Academy of Medical Sciences, U, S. S. R.)
Hany reports pointed out the value of work done on sanitary aspects of
industrial waste waters, on hygienic standardization of maxiniun permissible
concentrations of harmful matter in reservoirs and watersheds, on harmful sub-
stances of sewage in bottom deposits and on the effectiveness of installations
for the purification of waste waters containing oil, phenol, etc.
The Conference commented en the importance and timeliness of reports
dealing with the study of environmental radio-activity and with the use of
radio—active detectors in sanitary-hygienic investigations. The introduction
of radio-activity detectors by institutes of sanitation and hygiene in prac-
tical work and scientific research was regarded as imperative.
General problems of water microbiology were discussed in relation to
biocenosis. Also discussed was the importance of plankton and algae as fac-
tors accelerating reservoir self-purification processes and affecting accumu-
lation of newly synthesized organic matter of neutral and toxic nature.
Some participants presented reports on the survival in water of typhoid,
paratyphoid, dysentery and intestinal bacilli. The effect of aeration on the
dying rate-Qf dysentery micro-organisms, the effect of decomposition products
on the proliferation and death rate of intestinal typhoid, paratyphoid and
dysentery bacteria and on their mutability in water were, discussed at some
length.
Special emphasis was placed on the question of direct and indirect ef-
fects produced by mass development of phyto-planlcton on the survival period
of intestinal and pathogenic bacteria in water. Some authors voiced the opin-
ion that a sanitary evaluation of water—reservoirs and other water sources
should take into account all types of intestinal bacteria generally regarded
as indicative of pollution.
Chlorination of brucella- contaminated water with chlorine doses, normally
used in water supply sanitation was considered an adequate safeguard. Regu-
lations of COST 5216-50 prescribed for water analysis for intestinal bacteria
were subjected to criticism and the need for more precise procedures was em-
phasized*
-------
The opinion prevailed that the haptene ring precipitation reaction ap-
peared specific and sensitive and could be run parallel with a 'bacteriologi-
cal analysis, thereby serving as a guiding presumptive epidemic logical test
for the detection of typhoid, paratyphoid and dysentery micro-organisms,
since the test required not more than 18-20 hours. The possibility of
adapting baoteriophage for the same purpose was briefly mentioned. Some pa-
pers were presented which tended to prove that soil surface, surface of water
bodies and plants constituted primary and basic sources of bacterial air con-
tamination. Under natural conditions the processes of self-purification of
air and air-plankton are rather powerful.
Results of experiments in sanitary bacteriology pointed to the importance
of hemolytic and viridance streptococci as indicative micro-organisms in the
sanitary evaluation of air and to the values of chocolate agar as a selective
medium for streptococci.
Conferees agreed generally that equipment presently used for bacteriolog-
ical air ezamination by the aspiration method fell short of the desired. Ac-
cordingly, the need for the development of better apparatus for the qualita-
tive and quantitative analyses of atmospheric and indoor air was regarded as
an outstanding and urgent problem..
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Conference on Smokeless Charging of Coke Ovens
R. Z. Lerner
Glav}co:
-------
half of the oven chanber, from the center towards the coking side, After
the charge material of the middle hopper (hunker) has been unloaded the
leveling beam is moved to the middle hatch and operated in a similar manner;
the loading car is then moved away.
In this method the delivery cars are loaded with unequal quantities of
charge material. With a total load of 16.6 - 17*0 tons of charge material,
including actual moisture content, 3.0 - 3.5 tons are unloaded into the
middle hopper and 6.6 - 7.0 into each of the end hoppers. Accordingly the
loading cars must he of corresponding capacity. A cylinder is installed in
tha middle hopper to determine the limit of the charge. The holding capac-
ity of each of the end hoppera is increased "by 1.3 - 1.5 tons. Such method
of coke oven charging assures absence of smoke and the removal of minimum
charge excess by the leveling beam.
It is important that the charge be evenly distributed throughout the
length of the oven chambers, avoiding slants and spotted overloads ("humps").
For this reason the end, or nose, of the leveling beam is equipped with four
rotating blades; as the leveling beam is moved forward the blades push the
charge material towards the coking side; when the leveling beam is being
withdrawn the rotating blades automatically rise and assume a horizontal
position, thus preventing the charge material from being pushed towards the
operating side.
Another method of smokeless coke oven charging was considered at the
conference, which is still in the experimental stage. By that method the
removal of the material starts with the first hopper (bunker), followed by
the removal of the charge from the third hopper and lastly from the middle
hopper; simultaneously the leveling beam is in operation. The method ena-
bles the gases to pass into a special collector so that supplemental charg-
ing can be made through the middle hatch. It must be noted, however, that
the time of hopper emptying and leveling is considerably delayed by this
method. It is believed that less dust is carried over into the gas collec-
tors by this method due to-the fact that the gases are removed by suction
through the gas collector on the coka side when the bunker on the machine
side is emptied, and through the,gas collector on the machine side when the
bunker on the coke side is emptied.
This method of coke oven smokeless charging has been in operation at
the Moscow Coke-Gas plant for a long time; it should be put into operation
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in all coke-chemical plants. It should be noted here that at the Moscow
Coke-Gas plant one working "brigade operates 74 ovens, or 2 "batteries, with
a 14 hour coking period and 1 hour and 15 minutes intermission period.
Considerable amount of work was done in search of effective methods of
smokeless coke oven charging at the Giprokoks in cooperation with the
Zaporozhskii, at the VUKhIN in cooperation with the N,-Tagil'skii, at
UKhIN in cooperation with the Khar'kovskii, at the Bagleiskii and at the
Rutchenkovskii coke-chemical plants. Results of experiments showed that to
attain absolute smokeless coke oven charging a complex combination of mea-
sures must be brought into coordinated action. As a first step the tech-
nological phase of loading must be reorganized along the following lines:
1. The constancy of the charge material volume in the bunkers of the
loading cars must be assured; definite regularity of the automatic discharge
of material from the ovens must also be assured in accordance with the ex-
perience of the Zaporozhye Coke-Chemical plant.
2. The experience of the Zhdanovsk Coke-Chemical plant indicated that
the operation of the leveling beam must be automatic to insure even loading
of the coking chambers throughout the entire length, and to insure adequate
passageway for the removal of the gases into the gas collectors*
3. There must be mechanical provision for the pneumatic removal of the
charge material in the bunkers of the freight or loading cars, according to
the experience of the Moscow Coke-Gas plant; or the cars must be equipped
with vibrators similar to those used by the Zaporosh'e Coke-Chemical plant.
4. The leveling beams must be 280 mm wide instead of 240 mm.
5. The rate of movement of the leveling beams must be increased from
^2 to 90 meters per minute.
6. The diameter of the discharge openings of the loading car bunkers
must be widened to 500 mm.
7. The leveling beams must be provided with ball-and-socket an", rotat-
ing plates in accordance with the experience of the Moscow Coke-Gas plant.
8* Constancy of the charge material moisture must be assured; this is
important since variations in the latter affect the discharge rate of 'the
material from the loading car bunkers as well as the charging rate of the
coking chambers.
9* The steam pressure in the coking oven collectors oust not fall be-
low 7 atmospheres*
-240-
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1C* Graphite deposits in the coking chambers must "be completely ob-
viated*
The mechanization of the hatch openings should hasten considerably
the process of coke oven charging. It is suggested that the effectiveness
of such installations in other plants be checked and, if found practical,
their installation in all coke-chemical plants should be made mandatory.
The Conference approved the measures used for the mechanized clari-
fication of tars in many .plants and recommended the adoption of the follow-
ing: raising the tar level in the clarifiers to 1.5 meters; insuring an
uninterrupted flow of tar and other separate materials from the clarifiers;
lowering the temperatures of the separated settled components at the dis-
charge level; additional primary coolers should be installed inside the tar
clarifiers; level controls should be installed in the tar clarifiers; con-
necting pipe for the discharge of the tar from the tar clarifiers should be
raised to 0.5 meters from the bottom; a screen should be installed at the
point of water flow into the sleeve to screen out floating impurities (fuss);
install a partition at the level of tar discharge for the separation of
floating impurities (fuss); obviate the formation of clearance between the
scraper and the bottom, etc*
The presence of oxides of nitrogen in the gas supplied "by the coke-gae
industry to nitrogen-fertilizer plants presents a serious obstacle to the
adoption of the smokeless method of coke charging in coke-gas or coke-chem-
ical plants* The use of steam injection in connection with the smokeless
method of coke oven charging raises the content of oxides of nitrogen to a
considerable degree. The purification of coke-gas from nitrogenous admix-
tures must be improved. The Conference requested Giprokoks to develop other
than steam means of injection, such, for instance, as gas injection, or the
like.
At the Moscow Coke-Gas plant a different type of assembly is being in-
stalled at present by means of which coke oven charging can be done via one
hatch only. Glavkbks assigned the job of developing and producing the nec-
essary mechanical assembly to the Bureau of Glavmashmet* In accordance with
this new assembly the loading (freight) car will have to be rebuilt so that
the charge material of the outer bunkers of the loading car may be carried
over to the middle bunkers by means of worm conveyors and from the latter to
the coking chamber. The usual leveling beam is to be replaced by a leveler
-241-
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of two worm-gears working into opposite directions to move the charge mate-
rial simultaneously from the center to the machine and coking sides of the
chanter. The rotating motion of the worm-gear leveler will enable the
tighter closing of the leveling window. It is expected that the use of the
worm-gear leveler and the loading of the oven chamber vie one center hatch
may permit the adoption of the smokeless coke oven charging without having
to resort to high-pressure steam injection.
Conclusions.
1. The method of smokeless coke oven charging has been in use at the
Moscow Coke-Gas plant for over a year. It should new be adopted by all
coke-chemical plants during 1956-1957-
2. The attainment of complete freedom from smoke during coke oven
charging necessitates the introduction of many measures related to the au-
tomation of the process of loading the charge material.
3. UKhlH (Coal Chemical Institute of Khar'kov) and VUKhEJ (Ail-Union
Coal-Chemical Institute) and Giprokoks (Office of Planning Coke Projects)
must issue orders for the basic (radical) improvements in the operation of
the tar clarifiers.
4. In connection with the increase in the content of oxides of nitro-
gen in the coke gas incident to high pressure steam injection, the nitrogen
fertilizer industry' should be requested to install improved methods of
freeing coke gas from oxides of nitrogen at their own plants, theretqr facil-
itating the installation of the smokeless method of coke oven charging in
the coke-chemical plants*
-242-
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Dust-Retaining Properties of Leaves of So&e Tree Species*
1*
If. I. Gusev.
Proa the Ifedical Institutes of Tashkent and Ryazan.
Gigiena i Sanitariya, Ho. 6, 17-19t 1952.
A study was made in Tashkent of the dust-retaining power of leaves of
tree species listed in the Table. Investigations were made in She park of the
Ve.M«. Molotov Tashkent Medical Institute where theses tree species were grow-
ing in close proximity, exposed to the effects of dust from the main city
street and from the highway passing through the park. Observations on the
dust-retaining power of leaves were made mostly during the summer and fell
months of 1949* In the fall of 1950 tree-planted areas outside the Institute
park exposed to different dust concentrations were similarly investigated.
The technic of the study was as follows: 3 to 5 leaves were placed into Petri
dishes, brought to the laboratory and the dust washed off with distilled water.
The wash water from each species of leaves was divided into two equal portions,
which were poured into separate graduated cylinders.
The wash water from one of the cylinders was evaporated on a weterbath in
a weighed Petri dish and the residue dried at 105 • ?he wash water of the other
cylinder was filtered through nitrocellulose membrane filters Ros. 1, 2 and 3
in a Zeitz apparatus. The nitrocellulose membrane filters with the residue
were then dried at 105 and weighed. Results were expressed in grams per m
of leaf surface area* The latter pas determined as follows! the exact shape- -
of a single or of several leaves, as the case may be, was cut out from a weighed
sheet of paper of a known weight and area; the weight of the cut out section
was then determined and tha area of the section or sections of the paper, which
is the exact equivalent of the area of the leaf or leaves, was determined by
the aquation. At(/ffto - *a(/vge, or ^ - At() x »8e/Wto,
where A. denotes the total area of the sheet of paper,
W. denotes the total weight of the sheet of paper, —
a denotes the area of a single or several cut out paper sections
ee * f
equivalent to the area of a single or several tree leaves,
-243-
-------
w denotes the weight of a single or several cut out paper e act ions
so .
equivalent to the weight of a single or several tree leaves.
2
Final experimental results in terms of grams of dust per m of leaf are
shown in the appended Table. The data show that leaves of the smooth leaved
elm retained 2.3 times as much dust as did the leaves of the poplar and 1*5
times as much as leaves of the white ash. The leaves of all trees, the poplar
excepted, manifested a certain regularity in the amount of duut retained at
different seasons of the year:, the amount of retained dust increased from
June to September and decreased in October. Determinations made in November
were too few and are not shown in the Table. However, it can be generally
stated that they showed a marked decrease in dust retention. Poplar leaves
did not accumulate dust in a regular manner; this may be due to their smooth
shiny surface unsuited for catching and retaining dust.
In the fall of 1950 an investigation was made of the dust-retaining power
of leaves of the same tree species planted along the streets of the city of
TasUcent. City streets were chosen which were kept in equally good order, but
differed with regard to dust density caused by the nature of the traffic. The
results of this study are presented in the last two columns of the Table* As
a rule, the low or quantity of dust was found on the leaves of trees growing in
the less dusty streets; the maximal quantities were found on leaves of trees
growing close to intensive traffic. The difference between the maximal and
minima'? indexes of duat retained on the tree leaves was 1,5 to 2. The accumu-
lation of dust on leaves of different species of trees growing in the park was
not as great as in the city streets, but the difference in the dust-retaining
power of leaves of different tree species growing in.the city streets remained
in evidence.
Summary.
X, The dust-retaining power of leaves of different tree species varied
with the dust concentration in the air.
2. In the climate of the Uzbek S.S.R., where rains are scarce in the sum-
mer and fall, a steady accumulation of dust has been observed on the surface of
the leaves; it begins to decrease shortly before the leaves begin tc fall.
-244-
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I
l\>
-TS-
UI
i
Type of tree
Sagdiisk ash
Mulberry
Sugar maple- . .
Soap tree
White ash
Poplar :
Dust in g/o£ of leaf surf ace \ samples
collected in medical institute park
June
1,8128
1,5002
2,1745
1,7935
2,7377
: 2,4463
1,9145
1 ,8099
0,9862
. 0.7604
i,l598
'1,4917
1,3452
1,1684
1,2645
1,1810
0,2463
0.3047
July
'
2,7388
2,3700
2,4946
2,1590
2,9567
2,7273
2,2625
• 2,0927
2,0017
1,1*358
1,9786
1,7181
1,4891
1,2761
1 '243
I, *77
1,8764
1,6188
August
3,8529
3,4948
3,0896
2,9004
3,1241
3,0146
2,6317
2,5313
2,4740
2,1608
2,6779
2,4818
2,4999
2,2807
2,1714
1 ,81 15
1,8423
1 ,7623
Sept.
4,4922
3.PJ03
4,4122
3,9178
3,4508
3,3467
3,9214
3,0992
3,8853
3,tKiS5
2,8821
2,7964
3,7690
3,6/29
2,9761
2,8056
1,7039
1,6282
October
3,7137
3,5744
4,3482
4,0047
3,2440
2,9746
3,6483
3,5176
3,3812
3tlb92
2,9164
2,792»
2,7306
2,0346
2,5035
2,3757
1>6732
1,5065
s »
5 §>
3,3220
2,9734
3,3037
2,9547
3,1027
2,9091
2,7357
2,filOO
2,5457
2,33(13
2,4479
2,2562
2,3668
2,2065
2,1279
1,98 '3
1,4688
1,3841
From leaves of
street trees
Minim.
3,4922
3,1700
3,4782
3,1128
2,5817
2,3914
2,9110
2,8056
2,5112
2,27t>4
2,1654
2,0339
2,3716
2,2466
2,2968
2,1484
Maxim,
5.6818
5,3948
5,5122
5,1482
4,4500
4,2214
4,1424
4,1277
4,4740
4,2668
4,2118
4,0809
3,4412
3,2148
3,1812
3,0416
-------
Purification of Gases from Organic Sulfur Compounds with Activated
Clays of Georgia Origin.
Ta. D. Zel'venskii and I. G. Sarishvii.
Zhur. Prikladnoi Khimii, 29, Ho. 6, 833-341, 1956-
Combustible gases invariably contain noxious sulfur compounds and must be
purified before being used for poser or technological purposes. Hydrogen sul-
fide constitutes the greater p&rt of sulfur-containing gases, but some organic
sulfur compounds may also be present, such as carbon bisulfide, carbon oxysul-
fide, thiophene, mercaptana, sulfides and others. With the increased require-
ments for gas purification, the sulfur-containing gases should be purified not
only from hydrogen sulfide but also from the organic sulfur compounds* The
problem of removal of non-organic sulfur compounds has been technically solved;
as yet, no satisfactory technical solution has been found for the elimination
of the organic sulfur compounds from gases. The available literature contains
many methods proposed for the elimination of organic sulfur from gases (l).
The method herein described is based on the removal of sulfur compound va-
pors from a gas by a physical method, namely by the process of adsorption using
a solid porous adsorbent. Experience showed that the adsorption method compared
favorably with other methods because it operated at ordinary temperature, where-
as the catalytic or absorption method required gas pre-heating up to 200 or
higher. Activated charcoal is a most efficient adsorbent (2), but the object
of this study was to investigate the possibility of using certain activated
Georgia clays as the adsorbent. Among the several samples of sub-bentonite
clays tested, the activated askanglin (a term compounded from "Askanskaya Glina"
or Askanak clay. B.S.L.), also referred to as aekanite, and gumbrine (probably
similar to U.S.A. gumbo clay. B.3.L.) proved to be the best; hence, they *sre
used in this investigation. Gumbrine and askanglin differ only slightly in
their chemical and mineralogical composition. Both are composed basically of
mountmorillonite and are formed from volcanic rock and ashes disintegrated tor
the effects of water, carbon dioxide and other weathering factors (3). Gumbrine
is a product of a more basic transformation than is askanglin; for this reason
its adsorptive properties considerably excell those of clays from the Askanek
deposits. The sorption properties of askanglin and of low grade varieties of
-246-
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gumbrine can be considerably enhanced by activation with mineral acids.
The present study presents the results of determinations of the physical
and chemical properties of several grades of activated clays, and of the static
and dynamic processes of carbon bisulfide and thiopUene adsorption from flowing
gases. The study resulted in the development of a method for the regeneration
of spent sorbents. In the development of the new adsorption method of gas puri-
fication carbon bisulfide and thiophene were used as the two basic organic sul-
fur constituents of industrial gases. Thiophene content in gases is generally
low, but its elimination by the old methods proved difficult because of its
resistance to heat and to the action of chemicals. On the other hand, the
relatively high boiling point of thiophene and its high molecular weight fa-
cilitate its transformation to the condensed state in which its elimination
from gases by adsorption becomes expeditious and effective. The elimination
of carbon bisulfide and of thiophene from gaaes ^y actived clay adsorption was
effected with the aid of an apparatus shown schematically in Fig. 1.
The gas to which the organic compound vapors were added was air. Sulfur
compound determinations were made colorimetideally. The method for the deter-
mination of carbon bisulfide was based on the reaction between diethylamine and
Air
Fig* 1. A schematic drawing of the
laboratory setup
1 - Buffer solution container* 2 - monostat (pressure con-
trol); 3 - silicagel containers} 4. - flow meter} 5 - tf -
shaped tubej 6 - saturate^} 7 - temperature control} 8 —
gaa mi3»r} 9 -absorber solution containers j 10 - aspira-
tor} 11 - manometer} 12 - temperature control} 13 - con-
denser f 14 - dynamic tubes.
-247-
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carbon bisulfide in an alcohol solution in the presence of copper acetate, the
end product of which was pentamethylenedithiocarbamic acid, which in the pres-
ence of copper acetate produced a copper salt of a brown color (4). The method
for the determination of thiophene was based on the development of a blue
iodophenine solution resulting frost the reaction between i sat in and thiophene
in concentrated sulfuric acid (5).
The adsorption properties of the clays were enhanced by activation with
25# sulfuric acid at 100° for 5 hours* After the acid was washed off the ac-
tivated clays were molded into the desired sha;oe y a press. The physical and
chemical properties of the sorbents used are listed in Table 1.
T A B L B 1..
Fhysico-mechanical properties of some sorbant samples*
Sorbent
Activated askanglin
(askanite) of source
Bo. 1
Activated askanglin
of source So. 2
Activated askangliA
of source Bo. 3
Natural gumbrine
Activated gumbrine
•
ance |
pressures
in I
625
625
625
937
1250
-'
625
937
1250
Volume
0.67
0.61
0.44
0.75
0.44
6
{ Apparent s True
I specific t specific
Jin kg/1 ii in kg/li
1.35
1.28
0.93
0.96
1.38
1.47
0.81
0.87
1.32
2.58
2.18
1.94
1.96
1.87
2.60
2.05
2.10
1.95
i
Porosity i
i
•
t :
47.8
41.1
52.3
51.1
26.2
43.3
60.6
58.7
30.9
Density
"
-
92.2
94.7
97.3
94.3
96.0
98.5
The data in that Table show that high pressure used in molding the clays
reduced their porosity and increased their resistance to breakage; "but the
diminished porosity lowered their capacity of adsorb thiophena and carbon bi-
sulfide, as is shown ia Table 2*
" " " • O
The adsorbents were molded under a pressure of 625 kg^cm . since the prod-
ucts formed under a lower pressure were fragile. The static and dynamic phases
of thiophene and carbon bisulfide adsorption were studied with two grades of
adsorbents* activated gumbrine and activated askanglin from deposit Bo. 3}
-248-
-------
both possessed a higher sulfur adsorption capacity. The static adsorption
capacity of activated gumbrine and asfcanglin was found to rest within the fol-
lowing ranges of concentration in a gas: carbon bisulfide from 200 - 700 mg/m
and thiophene from 50 - 200 mg/m . These ranges embrace the concentrations of
thiophene and CS^ found in emission gases.
TABLE 2.
Effect of porosity on sulfur adsorption capacity at 20 C and concentration
in gas of thiophene - 200 rag/m^ and carbon bisulfide - 300 mg/m3.
Activated askanglin
Activated gumbrine
Adsorbat3
IPerformancei
tpressure in!
| kg/cm2 i
Sulfur ad- |
sorption
i
capacity
in % of {
tthe sorbent :
Porosity
| Sulfur ad- :
I sorption -
: capacity s
{ in % of |
ithe sorbent s
Porosity
Carbon
bisulfide
Thiophene
1250
937
625
1250
937
625
0.58
0.96
l.U
0.71
1.12
1*29
26.2
51.1
52.34
26.2
51.1
52*34
0.73
1.13
1-34
1.09
1.66
1.70
30.9
58.7
60.6
30.9
58.7
60.6
The results of adsorption capacity determinations of activated gumbrine
and askan&lin at 20° with reference to carbon bisulfide and thiophene are
shown as adsorption isotherms in Pigs. 2-4. The adsorption property of ac-
tivated guabrine is considerably greater than that of activated askanglin.
Results of their comparative studies are shown by the two isotherms in Pig. 4
plotted in terms of millimoles per gram of the adsorbent. Pig. 4 shows that
within the range of 1cm concentrations thiophene was adsorbed to a greater ex-
tent than carbon bisulfide. The data obtained can be expressed in the fora of
the following generalizations
i
a.W? (1)
where a is the value of adsorption in percent of the sorbent weight,
C is the sorbate concentration in mg/m of the gas. The values of k
and — are shown In Table 3. - ".""
n
Broken line curves in Figs. 2 and 3 are plotted as per equation (l).
Solid line plotc la Pigs. 2 and 3 correspond to Lang&uir's isotherm*
-249-
-------
a-i75c <2>
The values for a and b of equation (2) are shown in Table 3. The graphs
show that either type of equation can be used for interpolation with sn accu-
racy sufficient for technical calculation. Eh'e effect of temperature on the
adsorption capacity of thiophene and car-
bon bisulfide was determined in experi-
ments made at 10°, 20°, 35° and 50°. The
1.6
t.Z
1.0
0£
0.6
0.8
0.6
SO
100
150 ZOO
100 200 300 400 500 600 701
Fig. 2. Adsorption isotherms
of carbon bisulfide at 20°,
A - Carbon bisulfide adsorp-
tion capacity in $ of sorbent
weight. £ — Carbon bisulfide
concentration in the gas in
mg/nH. 1 - Activated gumbrine,
2 - Activated askanglin.
a — Exponential equation
curve, b — Langaaiir equation
curve.
Pig. 3. Adsorption
of thiophene at dv •
A- Thiph^no ^sorptioa
pacity in g of sorbent .
3 - fhiopK©Q3 concgtration
in th© gas in Kg/BT.
1 - Activated gumbrxne.
•2 - Activated as&anglin.
oneatial equation
b - LangEaiir equa-
tion
a -
u ••...._
Pig, 4. Comparison of adsozption of thiophene aad of carbon bi«-
sulfide (l) by activated gumbrine and (II) by activated a®kaa-
glin at 20°.
A — Thiophene avid carbon bisulfide adsorption capacity inj
2 - ¥hioph©ne and carbon bisulfide concentrations in rsccl/m .
Adsorption isothexmss 1 thiophenof 2 - carbon bisulfide.
-250-
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TABLE 3.
Values of adsorption isotherm equation constants at 20°C.
Equation
Ho.
« 1
(2)
x Equation
: constant
[ T
b
am
i
I
Activated
2 i
0.1440
0.3590
0.0025
2.44
sumbrina :
Thiophene t
0.3327
0.3090
0.0156
2.22
Activated
cs2
0.0628
0.4660
0.00209
2.19
askan&lin
Thiophene
0.1150
0.4000
0,01112
1.85
results are shown in Figs. 5 and 6. It can be seen that the amount of sulfur
compounds adsorbed decreased rapidly with increases in temperature. The heat
of adsorption computed as a temperature function, in the case of activated
guobrine or aekanglin was approximately the same in both cases. For the ad-
sorption of thlophene by the activated adsorbents the adsorption heat was 4560
cal/mol and for carbon bisulfide 2970 cal/mol.
For the determination of the effect of moisture on the process of gas
purification by activated clays, the gad was preliminarily humidified up to 40,
t.6
f.4
ft2
1.0
04
dfi
0 1C 20 30 40 fO
5* Effect of temperature
on carbon bisulfide adsorption
capacity at 500 mg/m3 of gas.
A — Carbon bisulfide adsorp-
tion capacity in % of sorbent
weight. B. ?6-:aperature in C°.
1 — Activated gumbrine.
2 — Activated
t.6
1.C
tLS
as
fa
zo jo w so
Pig. 6. Effect of temperature
on thiopliene adsorption capac-
ity at 20O mg/m3 of gas*
A - Thlophene adsorption capac-
ity in ^ of sorbent weight)
B - Temperature in C°«
1 - Activated gumbrine,
2 - Activated askanglin.
-251-
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60 and &0£ of relative humidity. The course of carbon bisulfide and of thio-
phene adsorption from & humid gas was as follows: in the beginning of the ex-
periment the first adsorbent layers adsorbed the moisture, and the following
layers retained the sulfur compounds. Subsequently, the adsorbed moisture
formation moved along the sorbent layer displacing the adsorbed sulfur compounds,
so that toward the end of the experiment, the concentration of sulfur compounds
at the exit of the sorbent layer was greater than at the point of the gas entry.
Thus, it is seen that activated gumbrine and askanglin lost their properties to
adsorb thiophene and carbon bisulfide in the presence of moisture. Therefore,
it is best that discharge gases be dried prior to being purified My adsorption.
To determine the degree of adsorption required to attain the desired degree of
gas purification use is generally made of the concept of dynamic activity,
which represents the amount of substance adsorbed by a unit weight of the sor-
bent prior to the onset of leakage or "passing through". In accordance with
the theory advanced by Shiloi, Lepin and Voznesenskii, the interrelation between
the dynamic activity and the length of a 3 *yer of the sorbent is expressed by
the following equation (6)t
A - a(l - ^) when L > LQ (3)
where A is the dynamic activity,
a is the static activity, or the adsorption capacity,
h is the unused thickness of the sorbent,
L is the total thickness of the sorbeat layer,
L is the working sorbent layer, i.e., extent of the zone in which ad-
sorption takes place.
The ratio of the dynamic activity to the adsorption capacity determines the
degree of saturation or the degree of utilization of the capacity of the sorbent
in the process of a dynamic experiment i
n-t (4)
Or, combining equations (3) and (4). we havet
•>-!-! " (5)
The dynamics of the process of gas purification from carbon bisulfide and
from thiophene was investigated for different gas velocities and different sop-
bent concentrations, with soxbant layer thickness of 10, 20, 30 and 40 cm.
-252-
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Equation (3) can "be plotted in the form of a straight lino curve for the con-
venience of resolving the experimental data as por equation (6).
Al - a(L - h) (6)
If the product Al is plotted along the T-axis and L along the X-axis then
the graph will be a straight line.
Such a graph constructed for the adsorption of thiophene by activated
gumbrine or activated askanglin is shown in Pig* 7* After a short initial
curved section both graphs assume the direction of a straigit line, i.e., the
experimental data are consistent with equations (3) and (6). A similar func-
tional relation was found to prevail under different experimental conditions
for the adsorption of carbon bisulfide* Equation (3) makes possible the ap-
plication of laboratory data to operating conditions on a larger scale.
The effect of rate of flow of a gas upon the course of purification was
studied experimentally with the gas flowing at rates of 18 - 106 ram/sec. The
degree of sorbent saturation as a function of the rate of gas flow is shown in
Pig. 8 for adsorption of carbon bisulfide at different thicknesses of the ad-
sorbent layer* A similar functional relation was obtained for thiophene ad-
sorption. With an increase in the gas flow the total amount of adsorbed sub-
60
so
to
30
zo
10\
0 10 20 30 W
Pig. ?• Effect of sorbent
layer hoight on thiophene
adsorption, at 200 mg/m*
and 53 mm/aec* of gas
floff rate.
A - Sorbent productivity
at height AL. B - Height
L of sorbent layer in CBU
1 — Activated gumbrine,
2 - Activated askanglin.
Fig. 8. Effect of gas flow rate
on the degree of sorbent satura-
tion with carbon bisulfide
A -Dsgroe of sorbent saturation t)
B - Rate of gas flow V in ES^see0
Sorbent layer height L in cmt
1 - 20, 2 - 40, 3 - 100.
a - Activated gumbrine.
b - Activated askanglin.
-253-
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stance increased during the aame time, but the degree of saturation and the
dynamic activity of the sorb ant a correspondingly decreased* Pig* 8 shows that
at all rates of gas flow the degree of sorbent saturation increased with the
thickness of the sorbent layer which is in conformity with equation (3). It
should be acted that the experimental data plotted for gumbrine and askanglin
formed completely coincidental curves as can be seen in Fig* 8* In other
words, the degree of saturation for both types of sorbents was identical under
identical conditions of adsorption. This fact indicates that the kinetic phase
of the gas purification by adsorption waa independent of the properties of the
sorbent but was controlled by the force of external diffusion. The final phase
of this study consisted of experiments for the development of means for the
regeneration of spent sorbehts* The regeneration was accomplished by blowing
air at 100° and 150° which ressved the adsorbed layers. The results of ex-
perimental desorption of thiophene from activated gmabrine by blowing hot air
at 53 mm/sec are shown in Fig. 9. Similar desorption curves were obtained
under different conditions. Pig. 9 shows that the method assured complete
removal of the adsorbed substances. Raising the temperature from 100 to 150
reduced the time for thiophene removal 1*5 times and of carbon bisulfide by
1*2 times.
The attained degree of regeneration was
determined with the aid of comparative tests.
The results showed that the sulfur compounds
adsorption capacity of the sorbents was fully
restored by the proposed regeneration method*
0 W 80 120 160 200
Pig. 9» Curve of thiophene Conclusions.
desorption from activated
gumbrine at different temp* 1. Results of trial tests with some sor-
A - Desorption in £, Desorp- bents for the purification of gases from thio-
from carbon bisulfide shewed that ac-
Teaperature in C°t
1 - 100. 2 - 150. tivated gumbrine and askanglic were highly ef-
fective for the purpose.
2* It was ascertained that too high a pressure used in molding the clays
decreased their sulfur adsorbing capacity per unit of sorbent due to the re-
duced porosity of the sorbent. A pressure of 625 feg/cm is recommended.
3. Tha sulfur adsorbing capacities of activated gumbrine and askanglixi
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were markedly affected by changes In temperature. The sorbents lost their
Ability to adsorb thiophene and carbon bisulfide in the presence of moisture.
4* Studies were cade cf the course of adsorption of carbon bisulfide and
of thiophene by activated gumbriae and askanglln. The results produced in-
formation regarding the effect of layer thickness, rate of gas flow and of
carbon bisulfide and thiophene concentration on the course of the sorbent
activity. The spent activated gumbrine and askanglin were completely regen-
erated by forcing through air at 100° - 150°.
5* Activated gumbrine and askanglin can be used in the purification of
dry gases, and in particular of coke gas fractions.
Bibliography.
[i] fl. fl. 3ejibBCHCKBu, JKXn, 6, 18 (1951). — [2] H. R. 3 GJI h ae B c K HH,
A. H. rpyaHHueoa. Tp. FHAII, 3. I'ocxuMuiuaT (1954). —[3] EenToaurotiLio
rjiHHU rpysnncKofi CCP. Cu. cra-rcii. Tp. Fpys. Toe. reonor. yiipasneHBg, 3.
TOHJIHCH (1941). — 14] McTOflbi oupe.ieJieHHn epcMawx Bemccrn » Bosayie. TOCT
6505—50. — [5] A. C. E p o y H, A. II. CuBepues. XHMHH rcpmicjux roe^HEenafi
jKHaicoro TODJiHea. XHMTeoper, JI. (1937). —JO] M. M. ^y6BHHU.
-------
Biological Action of Small Dose Huolear Radiation,,
By Academician P. A. Vlasyufc.
Doklady Vaesoyuanoi, Ordena Lenina Ateakemii, Sel'skokhozyayatvennykh,
Hauk Imeni V. I. Lenina, Vol. 10, pp. 8-14, 1937.
Natural radioactivity is an essential component of external environment.
Soils , the air close to the ground, soil moisture, matrices and plant tissues
contain a small but quantitatively determinable amount of radioactive elements.
Academician V. I, Vernadskii emphasized the necessity of taking into account
the effect of the earth's radioactivity on living organisms* The development
of nuclear physics made radioactive isotopes accessible to scientists thereby
widening the scope of studies of small dose ionizing radiation effects on plants.
Results of studies made by individual scientists, by research gx-cups, and in
particular by the Plant Physiology Institute at the Ukrainian Academy of Agri-
cultural Sciences indicated that the addition to a culture medium of radioactive
isotopes, the radiation of which exceeded only slightly natural radioactivity,
effected changes in the intensity of the physiological processes manifest^! as
increased vitality and productivity of the growing plant. Thus, the results
showed that limited quantities of nuclear radiation could affect plant growth
favorably. It can be assumed, therefore, that in the development of the organic
world radioactivity played, and ia still playing, a physiological role* This
problem merits the attention of research biologists,' since it offers the possi-
bility of determining the principles cf radio-biological activity and may lead
to results of practical significance. In this connection a critical analysis
should be made of the views expressed by some of our scientists on the biolog-
ical effects of small dose ionising radiation.
Academician A. P. Vinogradov performed a single experiment with
niger* a typical saprophyte, and on the basis of his results maintained that
K-40 radioactivity played no part in the growth and development of the fungus.
Be expressed the opinion that his conclusion was most probably applicable to
all plants, higher and lower* Such a sweeping conclusion should not have been
made without more extensive studies. And yet, without producing any additional
experimental evidence A. P. Vinogradov stated further that from the results of
his experiment it n..« follows that in the process of phylogenesis the pleats
did utilise natural radioactivity in their metabolic process „" The sama author
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indicated that he would present in the near future results of similar experi-
ments which would answer the question of effect of K-40 radioactivity on tis-
sues of animal organisms,
A* P. Vinogradov's article caused some scientists to doubt the results of
studies made by others on the effect of small dose isotope radiation on plant
growth. Speaking April, 1957 at the Ail-Union Conference on the use of radio-
active and stable isotopes and radiation in national economy, V.M. Klcchkovskii
stated, that "...The results of this experiment (A. P* Viaogradov's) cause one
to "be critical of all talk regarding the absolute necessity of a natural level
of radioactivity for plants." V. M. Elechkovskii felt that atomic energy could
find its basic application in the development of radiogenetics. Notwithstand-
ing results obtained by Stoglaza, Penkava, Pape, Eol'tsovs, Shtern, Zheahel1,
Vlaayuk and others, and without the support of experimental data, V.M. Klech-
kovskii doubted the prospect of utilizing radioactive substances as agents for
the increase of plants* growth and development and for the production of higher
and better crop yields.
Maximum yield is the basic goal of agriculture; this can be attained only
when the plants are provided with all conditions necessary for their proper
growth and development, including a certain level of radioactivity* In this
connection, the biological role played by natural radioactivity should be de-
termined. The statement by v* M. Klechkovskii that "Care should be taken to
avoid any radioactivity of agricultural products" disregards the fact that the
use of short-lived-isotopes excludes the possibility of radioactive pollution.
He also mentioned the difficulties and ensuing danger of controlling the admin-
istered radiation dosage* In the application of radioactive agents to seeds by
the presowing method it is not so much a question of dosage control as of skil-
ful manipulation.
It is strange, indeed, that one should disregard the positive effect of
small dose ionizing radiation on plants in the light of increasing experimental
evidence in. favor of it* Results of many studies indicated that the use of
small dose isotope radiation equal to or less than natural radioactivity con-
siderably increased the growth and development of plants*
Since 1^50 research lias been under way on the effects of ionising radia-
tion of radioactive isotopes on various agricultural plants, both in greenhouses
and field experiments, at the Institute of Plant Physiology of the Ukraine
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Academy of Agricultural Sciences* The studies were conducted with eulfur-35,
phosphorus-32, calcium-45» aine-65, and oobalt-60,. on sugar "beets, winter and
spring wheat, oats, barl*y, corn, lupine, potatoes, transplants of sugar beats,
tomatoes, flax, hemp, and a number of other agricultural crops* Tests of the
affects of ionizing radiation on plaits were carried out by the "blind key"
*
method in various zones of the Ukrainian S. S. K, on different soils: podzolic
meadow chernozem in the vicinity of Kiev; leached chernozem in Kiev region;
dark brown soils of the Kherson and Hikolaev regions; podzolio chernozem in the
A
Khmel'nitzk region, and many other soil varieties.
The following radiation methods were used* a) before sowing, the seeds
were soaked in radioactive salt solutions; "b) at various stages of plant de-
velopment reinforced fertilization by radioactive salts was applied. Etch test
2
was repeated 4-5 times; plots varied from 50 to 250 m and from 1-3 ha.
Results of plant productivity were statistically analysed. la most cases se-
ries of biochemical tests of the irradiated plants were made during the vege-
tative period, phenological observations were made continuously. Results of
tts early 1951 * 1952 experiments indicated that 5-3-16 jicurio of radioactive
phosphorus and 23-26 pcurie of zinc mixed with greenhouse soil increased the
root mass of sugar beets 1.5 - 2*0 times and their sugar content 0.7 - 1*5
times. In 1951 studies conducted in Kherson on an irrigated multicrop vegeta-
ble plot showed that small dose cobalt-60 radiation shortened the ripening pe-
riod of late tomato "Erasnodarets" by 5 - 7 days as compared with the non-ir-
radiated control plants. In 1953, on the Sovkhoa No. 13 of Kherson region ex-
periments were conducted with two tomato varieties, early "Hayak 12/20 - 4" and
late... "KraanodaretB." Radioactive cobalt was introduced as a top dressing
at the rate of 3-6-9-12 and 15 ixctirle per each. 50 plants. The test was repeat-
ed three times. To ascertain the effect of Co-59, , control plots received plain
Co salt top dressing in same amounts. la other plots plain Co top dressing was
increased up to 100 times. The total yield from all s!Mayak 12/20 - 4" control
variants amounted to 209 c/ha; with the Introduction of 3 gicurie of Co per
the yield was 255 c/ha; uith. a dose of 9 jicuri* per plant the yield wan 30$
o/ha. The "Krasnodareta" variaty in the control plots yielded 202 c/ba; with
radlocobalt dose of 12 (icurie por plant - 308 c/ha. As can bo seen from tho
data, the small doses of radioactive cobalt causod a considerable increase in
plant productivity. Tiolds from plants receiving normal cobalt top draosiag
1 The original Russian text states - Co-59» obviously a typographical error.
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differed from the original control by only 5*4 - 7-756. The properties of to-
matoes grown from radioactive cobalt treated plants were determined at the In-
stitute of Clinical Physiology of the Academy cf Sciences of the Ukrainian
S. S. B* Results showed that under conditions of experiments, cobalt-60 was
not accumulated in the tjmato fruits and no changes were noted in the nutri-
tional properties.
During 1950 - 1956 extensive research was conducted on the effect of small
dose radioactive substances of agricultural crops. The presowing seod treat-
ment with radioactive salt solutions proved to be an effective method for in-
creasing plant productivity. Pretreatment of sugar beet seeds with radioactive
P salt solution increased the root mass and the sugar content of the beets. In
20 greenhouse laboratory tests increase in weight of roots was as high as
114.9&. In one instance there was a 1*2% decrease in the mass. Increase in
weight of sugar beet roots of P-32 treated plants throughout all the test
years averaged 42,5^- Particularly noticeable changes occurred in the sugar
content which increased in some cases by 2.l£.- In one test of 20 the sugar con-
tent was 0.256 below the control* Increase in sugar content of beet roots
of P-32 treated plants over a period of five years averaged 0,79£> which is
regarded as a substantial improvement in biological crop properties of the
plants.
Treatment of sugar beet seeds with & solution of radioactive zinc salt
increased the weight of the roots and the sugar content* Low zinc-65 doses
increased the root mass up to 10Q$ as compared rfith the control; sugar content
increased up to 2.l£. In 14 greenhouse experiments performed during a five-
year period, decrease in root weight by 4.48$ occurred in only one instance.
Average increase in root weight for all experiments amounted to 21.2£ and in
sugar content 0.48£.
The effect of S-35 treatment of sugar beet seeds was slightly less effec-
tive than phosphorus or zinc. Haximum increase in root weight in ton green*
house tests was 49*53£ fty|^ root weight decreased >y 9.6£ in one case. Average
increase for root weight for all tests rcas 17»9£» and in sugar content 16«3£.
Tho average increase in weight of beet root grown from seeds treated with Ca«45
salt was 21.ffiS and 0.6£ in sugar content. The study of the influence of ion-
.ising radiations on sugar beet pro sowing treatment of the seeds with radioactive
iootopoe uaa done under conditions of field experimentation,
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In 1951 * 1956 field experiments were performed with ssads treated with
radioactive phosphorus prior to sowing. Ho decrease in yield was observed in
any test; in one test seed treatment with radioactive phosphorus salt had no
effect on the crop yield or sugar content. The ipaximum yield increase under
field conditions was 15*9£> and average 9*0$. Sugar content in 2 of 18 tests
was 0.1>6 and 0.06$ below the control; in the remaining 16 tests the sugar con-
tent increased to a maximum of 0,4$. Fifteen field teats ware performed with
radioactive zinc salts in which case maximum, yield increase was 21.6$ and aver*
age 8*2$. Ho yields were observed uslc™ the control and one equalled the con-
trol. MyHmum sugar content increase was 0.48$ and average 0.32$. ?ratreat-
ment of seeds with radioactive sulfur in the majority of 10 testa produced no
noticeable effects on the root yield, but it raised the sugar content in one
test "by 20.0$; in all other cases the increase ranged between 5 - 12$. The av-
erage increase in root yield was 7*7$ and in sugar content 0.49$.
Fratreatment of seeds with : Its of radioactive isotopes. favorably affected
the aeedbearing quality of the plants under field conditions* Thus, the treat-
ment with radioactive F-salts increased the seedbearing quality of the plants
by 11.4 - 13»5&» and treatment with radioactive ainc salt "by 10,45 - 12.1$;
treatment with radioactive sulfur salt reduced the plants* seedbearing capacity.
Laboratory isotope presowing seed treatment tests were performed with win-
ter wheat. Five greenhouse toste were performed with radioactive calcium salt;
the grain mass was increased up to 15*9£» average increase in grain weight of
five tests was 6.8$. Similar wheat grain treatment witu radioactive sine salt
increased the grain yield only to an average of 2.65$»
Under field conditions presowiug treatment of winter wheat with radioactive
phosphorus salt resulted in 10$ higher grain yield. No negative effects were
observed. Average increase of winter wheat grain yield In tests with radioactive
phosphorus was 5»8$. Better results were obtained with winter wheat top-dressed
with low doses of radioactive phosphorus salts at the beginning of the flowering
stage. In the majority of tests conducted in various aones of the Ukraine the
grain yield increased by 14.2$. In none of the teats was tha grain yield below
the control. Average increase in winter wheat grain yield of 10 tests amounted
to 8.88$. The increased seedbearing potential of the first generation progeny
was of a persistent character, as shown by an average 7*55£ increase in the
grain yield. Similar results were obtained with other cereal grains* Thus,
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tests with barley uadvi- field conditions produced an average grain yield in-
crease of 1?«9£» and winter xye, similarly tested, produced an average yield
increase of 11.7556. The crop was favorably affected "toy seed pretreatment with
radioactive sulfur, phosphorus and calcium salts« In none of the 17 experi-
ments was the yield below that of the controle Radioactive sulfur increased
the grain yield up to 10.7^ with an average of 5.7^ on the basis of four tests.
Radioactive phosphorus was more beneficial than sulfur-35- The marci mum yield
increase in field experiments was 15.7&* Average yield increase in nine ex-
perimente was 9*6£*
Preserving treatment of corn seeds with radioactive sine salt also increased
the yield* Average increase of four tests was 6.5£ with a maximum increase of
10.1$. Considerable increase in yield was observed in tomatoes exposed to the
effect of radioactive substances. Moot noticeable was the effect of cobalt
which was introduced in small amounts into the soil; in many cases the tomato
yield increased by 67«6*£. Ho decrease in the yield of tomato fruits was ob-
served \n any of 14 tests in which radioactive cobalt was introduced into the
soil; low increase in one of the testa occurred amounting to 5-4J6* Average
increase of 14 above described tests was 32.7$. Top dressing of tomatoes with
radioactive phosphorus salt during the flowering stage proved highly
beneficial; the increase in fruit yield ranged between 0.4 - 140.0£, with an
average increase of 11-8$. Thus, the presouing treatment of tomato seeds with
radioactive substances was also highly effective; radioactive zinc salt in-
creased ths yield by 11*33 - 22.4&. Fresowing treatment of seeds with radio-
active isotopes of phosphorus, sulfur and calcium gave less spectacular results.
Radioactive calcium and sulfur increased the yield by an average of 3.85^1
radioactive phosphorus increased the tomato yield of four test? by an average
of 4.7*._
Soaking of potato tubers in radio-isotope solutions of low activity under
field conditions and in experimental tests prior to planting was accompanied by
an increase in the potato crop, radioactive phosphorus exccpted. Radioactive
sulfur salt increased the tuber yield by 10.4 and 21.O£T and radioactive cal-
cium by 1336* Some of the cultivated plants did not react to small dose ionise-
tion radiation. Radioactive phosphorus, for instance, had no effect on the
yield of kok^saghys v?hon introduced into too soil under conditions of gre&n-
houso experimentation, choreas radioactive cobalt in traces increased the yield
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of kok-saghys "by 1556 and uranium "by 12.256. Top dressing of hemp with radio-
active isotopes caused a decrease in the hemp yield. Introducing radioactive
substances into the soil in greenhouse experiments increased the green tonage
of clover. It was noted that radioactive sulfur mixed with gypsum increased
the weight of clover plants "by an average of 23.956s however, there were cases
in which no such positive effects were manifest to any extent.
The effect of radioactive phosphorus on grapes was noteworthy. Root re-
inforcement with radioactive phosphorus salt of low activity increased the yield
by 20.6 - 20.9*. The same was true of tea loaves in which the yield increased
"between 10.4 - 13.2£. Lupine responded to treatment with nuclear radiation.
The presowiag treatment of its seeds with radioactive ainc salt increased the
green tortage by 13.4 - 13,62.
Studies of the mechanism of biological effect of ionizing radiation in-
dicated that the organism*& functional response followed a parabolic course.
Thus, at concentrations of lower radioactivity isotopes stimulated the total
metabolic and functional capacity of plants, and it can V-< assumed that ionizing
radiation is & genetic plant factor essential to normal growth and development
of plant life. Results of studies in the Ukrainian Institute of Plant Physiol-
ogy showed that under the influence of ionising radiation a biological buffer
system developed in the radiated plants which acted as an auxilliary factor to
reducing gluthathione and ascorbic acid. Together they affected the course of
oxidation-reduction processes and influenced the total course of the plants'
biochemical reactions. It was shown that as a result of the effect of small
radiocalcium dose on wheat plants during tha booting or tubulaticn stage the
biologically active substances characteristic of two-weeks-old sprouts pei>-
siated. It was shown experimentally that the beneficial effect of radioactive
isotopes came into evidence under unfavorable environmental conditions as an
aid to the plants* survival. This was indicated by the fact that radiated
plants under unfavorable ecological conditions produced greater yield increases
than similarly irradiated plants under normal control conditions; seeds treated
with radio-isotopes germinated under low temperature faster than did control
seeds under normal conditions of germination.
On the basis of results of field and greenhouse experiments conducted by
the Institute of Plant Physiology in a study of effects of radioactive isotopos
of low activity on cultivated farm plants, it can be concluded that the favor-
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able effect of small dose ionizing radiation on plants can be regarded as es-
tablished. It should be pointed out, however, that such effects may vary with
the nature of tbs ionizing radiation employed. This problem should be studied
more extensively for the promise it holds to open avenues of useful and bene-
ficial isotope application to the fields of biology and agro-chemistry.
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able effect of small dose ionizing radiation on plants can be regarded as es-
tablished* It should be pointed out, however, that such effects may vary with
the nature of the ionizing radiation employed. This problem should be studied
more extensively for the promise it holds to open avenues of useful and bene-
ficial isotope application to the fields of biology and agro-chemistry.
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