EPA-600/2-77-178
August 1977 Environmental Protection Technology Series
ELECTRON MICROSCOPE MEASUREMENT
OF AIRBORNE ASBESTOS
CONCENTRATIONS
A Provisional Methodology Manual
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Regional Center for Environmental Information
US EPA Region III
1650 Arch St.
Philadelphia, PA 19103
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
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This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
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EPA 600/2-77-178
August 1977
ELECTRON MICROSCOPE MEASUREMENT
OF AIRBORNE ASBESTOS CONCENTRATIONS
A Provisional Methodology Manual
by
Anant V. Samudra
Colin F. Harwood
John D. Stockham
IIT Research Institute
Chicago, Illinois 60616
Contract No. 68-02-2251
Project Officer
Jack Wagman
Emissions Measurement and Characterization Division
Environmental Sciences Research Laboratory
Research Triangle Park, North Carolina 27711
ENVIRONMENTAL SCIENCES RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U. S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, N. C. 27711
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DISCLAIMER
This manual has been reviewed by the Environmental Sciences Research
Laboratory, U. S. Environmental Protection Agency, and approved for publi-
cation. Approval does not signify that the contents necessarily reflect
the views and policies of the U. S. Environmental Protection Agency, nor
does mention of trade names or commercial products constitute endorsement
or recommendation for use.
ii
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FOREWARD
Asbestos or asbestiform minerals include several types or groups of
fibrous crystalline substances with special thermal and electrical
properties that have long encouraged their use in the manufacture of
such products as roofing, insulation, brake linings, fireproof curtains,
etc- Their occurrence as pollutants in the ambient air and in supplies
of food and drinking water has caused considerable concern because
occupational exposures to asbestos have been found to induce mesothelioma
of the pleura and peritoneum, as well as cancer of the lung, esophagus,
and stomach, after latent periods of about 20 to 40 years.
Electron microscopy is currently the principal technique used to
identify and characterize asbestos fibers in ambient air and water
samples. Because of the poor sensitivity and specificity of conven-
tional bulk analytical methods, electron microscopy is also being used
for routine measurement of airborne or waterborne asbestos concentrations.
The several laboratories that perform such analyses generally have
reasonable internal self consistency, However, interlaboratory compari-
sons have shown that the results obtained by the separate laboratories
are often widely different.
This manual describes a provisional optimum electron microscope
procedure for measuring the concentration of asbestos in air samples.
It results from a study, carried out under EPA Contract No. 68-02-2251,
to evaluate the various methods currently in use in the various labora-
tories. Statistical analysis was used to evaluate the effects of the
many interacting sub-procedures and arrive at an optimum composite
procedure.
This manual does not provide the vast amount of data that supports
the provisional methodology. These data are included in the final
report on EPA Contract No. 68-02-2251.
Jack Wagman
Project Officer
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ABSTRACT
This manual describes a provisional optimum electron microscope
(EM) procedure for measuring the concentration of asbestos in air
samples. The main features of the method include depositing an air
sample on a polycarbonate membrane filter, examining an EM grid specimen
in a transmission electron microscope (TEM), and verifying fiber
identity by selected area electron diffraction (SAED).
This provisional manual results from a study to develop an optimum
EM procedure for airborne asbestos determination. The analytical data
supporting the provisional methodology are included in a separate final
report.
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TABLE OF CONTENTS
1. PROVISIONAL METHODOLOGY-SUMMARY 1
2. METHODOLOGY 3
2.1 Air Sampling 3
2.1.1 Air Sampling Parameters 3
2.1.2 Sample Time Periods 4
2.2 Sample Storage and Transport 5
2.3 Carbon Coating the Filter 6
2.4 Transfer of the Sample to the EM Grid 8
2.5 Examination of the Grid by Transmission Electron .
Microscopy ........... 10
2.5.1 Low Magnification 10
2.5.2 High Magnification 11
2.5.2.1 Calibrating Magnification at
Fluorescent Screen 11
2.5.2.2 Loading Levels 11
2.5.2.3 Fiber Counting Rules 11
2.5.2.4 Fiber Classification Rules .... 13
2.5.2.5 Counting at Low Loading Level . . 15
2.5.2.6 Counting at Medium Loading Level . 15
2.5.2.7 Counting at High Loading Level . . 16
2.6 Recording of Data 16
2.6.1 Recording Format 16
2.6.2 Computer Coding Forms 18
2.7 E.M. Data Analysis 18
2.7.1 Checking Data on Key Punch Cards 18
2.7.2 Separating Very Large Sized Bundles .... 18
2.7.3 Fortran Program for Obtaining Characterizing
Parameters 19
2.7.4 Print Out of Results on Each TEM Grid ... 19
2.7.5 Summary of Results for a Typical Air Sample 19
2.7.6 Precision of TEM Estimates 19
2.7.7 Analyzing Data on Very Large Bundles of
Fibers 20
2.8 Ashing, Sonification and Reconstitution 20
v
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TABLE OF CONTENTS (cont.)
2.9 Limits of Detection 22
3.0 Preparation of Blanks 24
References 25
Appendix A - Instrumentation and Supplies 26
Appendix B - Magnification Calibration 32
Appendix C - Listing for the Fortran Program CONLAB .... 35
Appendix D - Illustrative Tables 39
vi
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LIST OF TABLES AND FIGURES
Table Page
1 Suggested Sampling Times for Determining
Airborne Asbestos Concentrations 5
2 Data Recording Sheet 17
3 Minimum Detection Limit Using High-Volume Air
Sampler 23
Figures
1 Modified Jaffe Washer Method 9
2 Two Methods of Examining a Grid 12
vii
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ELECTRON MICROSCOPE MEASUREMENT
OF AIRBORNE ASBESTOS CONCENTRATIONS
A Provisional Methodology Manual
1. PROVISIONAL METHODOLOGY - SUMMARY
(1) Take an air sample on a polycarbonate membrane fil-
ter, 0.4 ym, using a high-volume or personal sampler.
(2) Coat the filter and deposit a 40 ran thick film of
carbon via a vacuum evaporator.
(3) Transfer the deposit from the polycarbonate filter
to an electron microscope grid using a modified Jaffe washer.
The Jaffe washer is prepared as follows. A 60 or 100 mesh
stainless steel mesh is placed on top of a paper filter stack
or foam sponge contained in a petri dish. Chloroform is care-
fully poured into the petri dish until the level is just
touching the stainless steel mesh. A 3 mm portion of carbon
coated polycarbonate filter is placed particle side down on
a 200 mesh carbon coated copper electron microscope (EM) grid
and this pair is placed on the steel mesh. The 3 mm portion
is wetted with a 5 y£ drop of chloroform. The polycarbonate
filter will dissolve in about 24 to 48 hours.
(4) Examine the EM grid under low magnification in the
TEM to determine its suitability for high-magnification examin-
ation. Ascertain that the loading is suitable and is uniform,
that a high number of grid openings have their carbon film
intact, and that the sample is not contaminated.
(5) Systematically scan the EM grid at a magnification
of about 20.000X. Record the length and breadth of all fibers
that have an aspect ratio of greater than 3:1 and have sub-
stantially parallel sides. Observe the morphology of each
fiber through the 10X binocular and note whether a tubular
structure characteristic of chrysotile asbestos is present.
Switch into SAED mode and observe the diffraction pattern.
1
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Note whether the pattern is typical of chrysotile or amphibole,
or whether it is ambiguous or neither chrysotile nor amphibole.
(6) Count 100 fibers in several grid openings, or alter-
natively, count all fibers in at least 10 grid openings. If
more than 300 fibers are observed in one grid opening, then a
more lightly loaded filter sample should be used. If no other
filter sample can be obtained, the available sample should be
transferred onto a 400 mesh grid. Processing of the sample
using ashing and sonification techniques should be avoided
wherever possible.
(7) Fiber number concentration is calculated from the
following equations
Flbers/m3 - Total No. of Fibers
No. of EM Fields
Total Effective Filter Area. cm^
2
Area of an EH Field, cm
1
.
Volume of Air Sampled, m
Fiber mass for each type of asbestos in the sample is calculated
by assuming that the breadth measurement is a diameter; thus,
the mass can be calculated from
7T 2
Mass (yg) = — • (length, pm) • (diameter, ym)
4
• (density, g/cm^) • 10"^
3
The density of chrysotile is assumed to be 2.6 g/cm , and of
amphibole 3.0 g/cm^. The mass concentration for each type of
asbestos is then calculated from
Tot^l Mass
Mass Concentration ^ of all Fibers of that Type
Particular Type Volume of Air Sampled (m )
2
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(8) Other characterizing parameters of the asbestos
fibers are:
(a) Length and width distributions of chrysotile
fibers
(b) Volume distribution of chrysotile fibers
(c) Fiber concentration of other asbestos minerals
(d) Relative proportion of chrysotile fibers with
respect to total number of fibers
2. METHODOLOGY
2.1 Air Sampling
Collect the sample of airborne asbestos on 0.4 ym pore
size polycarbonate membrane filters. Use the high-volume air
sampler [1]* or, in certain instances, the personal dust
sampler [2]. The shiny, smooth side of the polycarbonate fil-
ter should be used as the particle capture surface.
2.1.1 Air Sampling Parameters
Sampling rates vary with the type and model of sampler
and with the type and pore size of filter used to collect an
air sample. Typically, a high-volume air sampler fitted with
a 20 cm x 25 cm, 0.4 ym pore size, polycarbonate filter will
have a flow rate of about 700 £/min (25 cfm) at a pressure drop
of 145 cm of water across the filter. By comparison, a per-
sonal dust sampler, operated with a 37 mm diameter, 0.4 ym pore
size, polycarbonate filter, is set, by a flow controller, to
sample at a flow rate of 2 d/min. The pressure drop across the
filter is 20.9 cm of water.
The two types of samplers can be compared by dividing the
volumetric flow rate by the effective filtration area of the
filters. The high-volume sampler, with an effective filtration
9 3 2
area of 406.5 cm , operates at a rate of 28.7 cm /cm /sec while
the personal dust sampler, with an effective filtration area* of
2 3 2
6.7 cm , operates at a rate of 5.0 cm /cm /sec. Thus, the
* Numbers in brackets denote the literature references.
* The effective filtration area varies with the style or
manufacturer and hence should be measured.
3
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filtering rate of the high-volume sampler is about five times
higher than that of the personal sampler. Some research inves-
tigators contend that the higher face velocity of the high-
volume sampler results in a lower fiber retention efficiency.
These investigators expect the fibers to align perpendicular
to the collection filter and, hence, better able to penetrate
through the pores in the filter. They recommend collecting air
samples at as low a face velocity as feasible and proportionately
extending the sampling time. The optimization study, upon which
this provisional methodology is based, tends to support the con-
tention but the reason remains obscure.
Personal dust samplers are used frequently to assess respir-
able dust levels. When used in this mode, they are preceeded
with a nylon cyclone that collects fibers and other particles
with aerodynamic diameters in excess of 10 pm. To be comparable
with the results of the high-volume sampler, it is recommended
that the personal sampler be operated without the cyclone
It is recommended that a cellulose acetate membrane filter
with a pore size of 5 ym be used to support the polycarbonate
filter in the samplers. It should be placed between the poly-
carbonate filter and the wire mesh filter support of the high-
volume sampler, or the glass frit filter support of the personal
sampler. The cellulose acetate membrane acts as a diffusion
plate and aids in obtaining a uniform deposit on the polycarbon-
ate filter. It also decreases the possibility of contaminating
the filter with particles from the sampler frame.
2.1.2 Sample Time Periods
As a guide, the following time periods are suggested for
the sampling of airborne asbestos. It is recommended that
samples be collected at all three of the suggested time periods
until experience dictates otherwise. Sampling at the three time
periods increases the probability that one of the samples will
be suitably loaded with asbestos to permit quantification of the
asbestos by the direct transfer technique.
4
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Table 1
SUGGESTED SAMPLING TIMES FOR DETERMINING
AIRBORNE ASBESTOS CONCENTRATIONS
Proximity
to Source
Sampler
Type
Suggested Sampling Times, min
Point Source
90 m
High-volume
Personal
15, 30, 60
75, 150, 300
Near Source
90-180 m
High-volume
Personal
30, 120, 480
150, 600
Distant Source
0.8-1.6 km
High-volume
Personal
240, 480, 1440
not recommended
2.2 Sample Storage and Transport
After acquiring the sample, every precaution must be taken
to assure its integrity and prevent contamination and loss of
fibers until the sample is examined under the electron micro-
scope. The polycarbonate filter should be removed immediately
from the filter holder with great care and tacked, with cello-
phane tape, to the bottom of a clean plastic petri dish. The
dish cover should then be secured and all necessary sample
identifying marks and symbols applied to the cover. With the
20 cm x 25 cm high-volume filters, it may be necessary to cut
the filter into 5 cm x 5 cm segments and store each segment in
separate petri dishes. A consistent notation must be used so
that the location and orientation of each segment with respect
to the original filter is not lost. It is recommended ,that the
petri dishes containing the filters be maintained in a horizontal
position at all times during storage and transportation to the
analyzing laboratory. At the present time, there are no reliable
estimates on the loss of fibers from polycarbonate filters prior
to carbon coating the filters in the laboratory.
5
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Suitable blank and standard filters should be introduced
at this stage in the analytical process and carried through
the remaining procedures along with the samples.
2.3 Carbon Coating the Filter
The polycarbonate filter with the sample deposit and
suitable blanks and standards should be coated with carbon as
soon after sampling is completed as possible. The carbon
coating forms an almost continuous film over the filter and
bonds the collected particles to the filter surface. Losses
are thus reduced during subsequent handling of the filter,
and during the transfer process to the electron microscope
grid. A carbon film of about 40 ran thickness is most suitable.
All experimental equipment and supplies are listed in Appendix A.
It is highly recommended that the handling and processing
of the filters after their receipt by the analyzing laboratory
be conducted in a clean room or clean bench to reduce the
possibility of contamination. Tweezers should be used far
handling the filters; static charge eliminators will facilitate
handling of the polycarbonate filters by neutralizing the sur-
face electrostatic charge.
Because a thin, uniform, carbon film is desired, the
coating of the filter deposit with carbon should be carried
out in a vacuum evaporator. Carbon sputtering devices should
be avoided because they produce a film of -uneven thickness.
A film too thick can lead to problems during the subsequent
steps in the procedure, particularly filter dissolution, fiber
sizing, and fiber identification.
Typically, vacuum evaporators accept samples as large as
10 cm in diameter. Thus, if the personal sampler was used for
sample collection, the entire filter may be carbon coated at
one time. It is convenient to use the petri dish in which the
polycarbonate filter is being stored. After inspecting the
filter to be sure it is securely tacked to the bottom of the
6
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petri dish, remove the cover and place the bottom of the dish
containing the filter in the vacuum evaporator for coating.
If the airborne asbestos was collected on the 20 cm x 25 cm
polycarbonate filter using the high-volume sampler, the
entire filter cannot be coated at once. Portions, about
2.5 cm x 2.5 cm, should be cut from the central region of the
filter using scissors or scalpel. Dead center is not necessary
and edges should be avoided. The portions should be tacked
with cellophane tape to a clean glass microscope slide and
placed in the vacuum evaporator for coating.
Any high-vacuum, carbon evaporator may be used to carbon
coat the filters (caution again: carbon sputtering devices
should not be used). Typically, the electrodes are adjusted
to a height of 8-10 cm from the level of the turn-table upon
which the filters are placed. A spectrographically pure car-
bon electrode sharpened to a 0.1 cm neck is used as the
evaporating electrode. The sharpened electrode is placed in
its spring-loaded holder so that the neck rests against the
flat surface of a second graphite electrode. The samples, in
either a petri dish bottom or on a glass slide, are attached
to "the turn-table with double-sided cellophane tape.
The manufacturer's instructions should be followed to
obtain a vacuum of about 1 x 10""* torr in the bell jar of the
evaporator. With the turn-table in motion, the carbon neck is
evaporated by increasing the electrode current to about
15 amperes in 10 seconds, followed by 25-30 seconds at
20-25 amperes. The evaporation should proceed in a series of
short bursts until the neck of the electrode is consumed.
Continuous prolonged evaporation is not recommended since
overheating and consequent polymerization of the polycarbonate
filter may easily occur and impede the subsequent step of
dissolving the filter. The evaporation process may be
observed by viewing the arc through welders goggles. (CAUTION:
never look at the arc without appropriate eye protection.)
7
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3
A rough calculation shows that a graphite neck of 5 mm volume,
when evaporated over a spherical surface of 10 cm radius, will
yield a carbon layer 40 nm thick.
After carbon coating, the vacuum chamber is slowly
returned to atmospheric pressure, the filters are removed and
placed in clean, marked petri dishes, and stored in a clean
bench.
2.4 Transfer of the Sample to the EM Grid
The transfer of the collected airborne asbestos from the
coated polycarbonate filter to an electron microscope grid is
accomplished in a clean room or bench using a Jaffe washer
technique [3] with some modification.
Transfer is made in a clean glass petri dish about 10 cm
diameter and 1.5 cm high. Into the dish a stack of 40 clean,
5h cm diameter paper filter circles is placed; alternatively,
a 3 cmx3 cm x 0.6 cm piece of polyurethane foam (like those
used as packing in Polaroid film boxes) may be used. Spectro-
scopic grade chloroform is poured into the petri dish until it
is level with the top surface of the paper filter stack or the
foam. On top of the stack or foam a piece of (about 0.6 cm
x 0.6 cm) 60-mesh stainless steel screen is placed. Several
transfers may be completed at one time and a separate piece of
mesh is used for each grid. Details of the modified Jaffe
washer and the washing process are illustrated in Figure 1.
Sections of the carbon-coated polycarbonate filter on
which the sample is deposited are obtained either by using a
punch to punch out 3 mm discs or a sharp scissors to cut out
approximately 3 mm x 3 mm squares. A section is laid carbon
side down on a 200-mesh carbon-coated electron microscope
(TEM) grid. (Alternatively, one may use formvar-coated grids
or uncoated TEM grids. Here the carbon coat on the polycarbonate
filter forms the grid substrate.) Minor overlap or underlap of
the grid by the filter section can be tolerated since only the
8
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(a) Plan of Jaffe Washer
Stainless Mesh
EM Grid
JS
0)
4)
X
0)
01
u
CO
o
0>
o-
1—1
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central 2 mm diameter portion of the grid is scanned in the
microscope. This pair (TEM grid and filter section) is picked
up with tweezers and placed carefully on the moist stainless
steel mesh of the Jaffe washer. The 3 mm section is wetted
immediately by a 5 pi drop of chloroform.
When all the samples are in place in the washer, more
chloroform is carefully added to increase the level to where
it just touches the top of the paper filter stack. Raising
the chloroform level any higher may float the TEM grid off the
mesh or displace the polycarbonate filter section; neither is
desirable. The cover is placed on the washer and weighted to
improve the seal and reduce the evaporation of the chloroform.
More chloroform should be added periodically to maintain
the level within the washer. After a minimum of 24 hours, the
polycarbonate filter should be completely dissolved. The TEM
grid is removed by picking up the stainless steel mesh with
tweezers and placing it on a clean filter. When all traces of
chloroform have evaporated, the grid may be lifted from the
mesh and examined in the electron microscope or stored for
future examination.
2.5 Examination of the Grid by Transmission Electron
Microscopy
2.5.1 Low Magnification
The grid is observed in the transmission electron micro-
scope at a magnification of 500X to determine its suitability
for detailed study at high magnification. The grid is rejected
if:
(a) The carbon film over a majority of the grid opening
is damaged and not intact. If so, the transfer
step 2.4 fiiust be repeated to obtain a new grid.
(b) The fibers give poor images and poor diffraction
patterns due to contamination. If so, the filter
may be ashed, redispersed, and refiltered (see
Section 2.8).
10
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2.5.2 High Magnification
2.5.2.1 Calibrating Magnification at Fluorescent Screen
It is important to know the exact value of magnification
at the fluorescent screen for the most common settings of the
electron microscope. The method for calibrating magnification
is illustrated in Appendix B.
2.5.2.2 Loading Levels
The method for examining the grid for fiber counting is
a function of the fiber loading on the filter. Three general-
ized loading levels may be encountered.
(a) Low Loading -- less than 50 fibers in a full grid
opening (80 vim x 80 urn) .
(b) Medium Loading — 50 to 300 fibers in a full grid
opening.
(c) High Loading -- more than 300 fibers per full grid
opening.
2.5.2.3 Fiber Counting Rules
In making a fiber count, the following rules are to be
observed:
(a) A field of view is defined. In some microscopes,
it is convenient to use the central rectangular
portion of the fluorescent screen which is lifted
for photographic purposes [see Figure 2(a)]. On
other microscopes, a scribed circle or the entire
circular screen may be used as the field of view.
The area of the field of view must be accurately
measurable.
(b) All fibers within the field of view are counted and
their length and width estimated and noted.
(c) Fibers which extend beyond the perimeter of the
field of view are counted. The width of these
fibers is measured but their length is measured
as only that portion which lies within the field
of view. Such fibers are noted by the letter "L"
as the length information is recorded, indicating
that it is a limit case [see Figure 2(a)]. In the
final analysis„ such fibers are treated as half-
fibers (half-counts).
11
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(d) Tightly bound bundles of fibers are counted as a
single fiber and an estimate made of their average
length and width. Fibers which touch or cross are
counted separately. Some subjective judgement is
required but fortunately, borderline cases are rare.
Notation is also made in recording the data that the
fiber was a bundle.
(e) Selection of the grid opening and the selection of a
field of view within a grid opening should be done
on a random basis [see Figure 2(b)], This is
important for avoiding biases and to ensure the
statistical validity of the results.
(f) Morphological comparison with standard specimens is
used as a basis for rejecting non-asbestos particles
such as plant parts and diatoms. Where doubt
exists, the electron diffraction pattern of the
particles should be examined.
2.5.2.4 Fiber Classification Rules
Fibers are classified by observation of their morphology
and electron diffraction patterns. It is recommended that both
morphological and diffraction pattern study be done at zero
degree tilt angle. Neither the morphology, nor the electron
diffraction pattern, nor even both, can give irrefutable proof
that a given fiber is asbestos. Positive results from the
tests indicate only that asbestiform fibers are present.
However, when samples are collected near a known source of
asbestos, the probability is extremely high that the observed
fibers are indeed asbestos.
The following rules should be followed when classifying a
fiber:
(a) Observe a fiber at a TEM screen magnification of
about 20,000X through a binocular with a magnifi-
cation of about 10X. At a screen magnification
of 20.000X, the tubular structure of chrysotile
asbestos is usually apparent (compare with standard
specimens). Fibers showing the tubular structure
may be classified as chrysotile asbestos with con-
fidence. There are only rare exceptions; amphibole
asbestos usually have a lath shape; but sometimes
appear similar in form to chrysotile fibers without
lumina.
13
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(b) Electron diffraction patterns from particles with
fibrous morphology fall into distinct groups.
Chrysotile asbestos has a characteristic streaked
layer line through the central spot and also a
triple set of double spots on the second layer
line. Amphibole asbestos gives a layer pattern,
generally with little or no streaking.
(c) Transmission electron micrographs and selected area
electron diffraction patterns obtained with standard
samples should be used as guides to fiber
identification [4,5].
From the examination of the electron diffraction patterns,
fibers are classified as belonging to one of the following
categories:
chrysotile
amphibole
ambiguous
non-asbestos
unknown (no pattern)
It should be noted that other particles with fibrous mor-
phology also give layer patterns; for example, hornblende. The
complete quantitative indexing and deriving interplanar d-spacings
from diffraction patterns is a time consuming and complex under-
taking and is not feasible for routine analysis.
It is not possible to inspect electron diffraction patterns
for some fibers even when their identity as asbestos fibers is
known. There are several reasons for the absence of a pattern.
These include contamination of the fiber, interference from
nearby particles, too small a fiber, too thick a fiber, and
non-suitable orientation of the fiber. Some chrysotile fibers
are destroyed in the electron beam resulting in patterns that
fade away within seconds of being formed. Some patterns are
very faint and can be seen only under the binocular microscope.
In general, the shortest available camera length must be used
and the objective lens current may need to be adjusted to give
14
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optimum pattern visibility for correct identification. Use of
a 20 cm camera length and a 10X binocular to inspect the SAED
pattern on the tilted screen is recommended.
2.5.2.5 Counting at Low Loading Level
When fewer than 50 fibers per grid opening are encountered,
the preferred counting method is to scan the entire grid opening
and defining the full grid opening as one field. With the
microscope magnification at 20,000X, a series of parallel scans
across the grid square are made starting with the top corner
of the square and ending at the bottom [see Figure 2(c)].
(With the tilting section of the fluorescent screen used as a
single field of view, approximately 300-400 fields will be
observed if the entire grid opening is scanned.) Fibers noted
in each full grid opening (or single field) are classified in
accordance with the procedure described above.
Additional grid openings are selected, scanned, and
counted until the total number of fibers counted exceeds 100,
or a minimum of 10 grid openings have been scanned, whichever
occurs first.
2.5.2.6 Counting at Medium Loading Level
When the loading on the filter is in the range of 50 to
300 fibers per grid opening, counting is done on randomly
selected fields of view. At a screen magnification of 20,000X,
fields are randomly selected within a grid opening until a
total of 20 fibers have been counted, sized, and classified.
(Generally 20-40 fields of view are observed per grid opening.)
After about 20 fibers have been counted, another grid opening
is selected and an additional 20 fibers (approx.) are counted.
This procedure is repeated for 5 grid openings until a minimum
of 100 fibers are counted. (When estimating fibers of a parti-
cular type of asbestos, counting is continued until 50-100 fibers
of that type are counted.)
15
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2.5.2.7 Counting at High Loading Level
When the fiber loading exceeds 300 fibers per grid
opening, the filter should ideally be rejected in favor of
a filter sample taken for a shorter time period.
If no other filter sample is possible and the number of
fibers above 300 is not too great (up to 400), then a filter
section should be transferred to a 400 mesh grid and the pro-
cedure repeated as for medium filter loading levels.
When the loading level is so high that fibers touch and
overlap and no other sample is available, then the filter
should be ashed, dispersed, and refiltered to yield a lower
concentration level. Details for this procedure are given
in Section 2.8.
2. 6 Recording of Data
It is advantageous to record the TEM data in a systematic
form so that it can be transferred to computer data cards for
statistical analysis.
2.6.1 Recording Format
A suggested data sheet format is shown in Table 2. The
entries at the top describe the sample (identification, the
storage box, and storage location), the sampling parameters
(volume of air sampled, total effective area of the filter),
and the TEM parameters (screen magnification, area of one
2
field of view in cm , etc.).
Column 1 -- EM grid opening identification number
Column 2 -- Identification number for the field of view
Column 3 -- Fiber sequence number within a given field
of view
Column 4 -- Cumulative number of fibers counted
Column 5 -- Fiber width in mm
Column 6 -- Fiber length in mm
16
-------
Table 2
DATA RECORDING SHEET
Sample:
Vol.
of Air Sampled: 9.
o
, z m
Storage Box No.:
Effective Area
o
of Membrane: 406.5 cm
Location
in Box:
Magnification: 17,
000
Area of
One Field:
0.182 x
10'6 cm2
Grid
Field
Fiber
Fiber
Fiber Identification
Opening
of View
Fiber
Cumulative
Width,
Length,
by Morphology and
I.D.
Number
Number
Fiber Count
mm
mm
Electron Diffraction
1
1
1
1
1.0
20
Chrysotile
2
2
0.25
7
Ambiguous
2
1
3
0.5
17
Ambiguous
2
4
1.0
10
Chrysotile
3
5
1.0
18
Chrysotile
4
6
0.75
22
Chrysotile
5
7
1.0
12
Chrysotile
6
8
0.5
10
No Pattern
3
1
9
0.25
24
Chrysotile
2
10
0.75
18
Ambiguous
3
11
1.0
10
Chrysotile
4
12
1.0
8
Chrysotile
5
13
0.25
10
No Pattern
4
1
14
0.25
6
Chrysotile
2
15
0.25
20
Ambiguous
3
16
0.5
5
No Pattern
5
1
17
2.0
65
Chrysotile
2
18
1.0
10
Ambiguous
3
19
0.5
4
No Pattern
and so on.
-------
Column 7 -- Fibers extending beyond the perimeter of the
field, marked with L (limiting case)
Column 8 -- Fiber identification, chrysotile, amphibole,
ambiguous, or no pattern or non-asbestos
2.6.2 Computer Coding Forms
A Fortran program has been developed (see Appendix C) to
analyze the data obtained from the electron microscopy study.
In order to use this Fortran program, it is recommended that
data from the notes be transferred to IBM computer coding
sheets to facilitate key punching. The coding scheme is given
in Table D-l and an illustration is presented in Table D-2 of
Appendix D. The scheme is sufficiently broad to keep all
relevant information, such as sample code number, laboratory
code number, operator code number, TEM grid number, etc.
Ashing factor refers to the dilution or concentration resulting
from the ashing and reconstitution step. It is defined as the
ratio of the redeposition filter area to the area of the filter
2
segment ashed. For example, if 5 cm segment was ashed and the
ash suspension deposited on 25 mm diameter final filter
2
(effective area 2 cm ), the ashing factor is 0.4. The area of
the field of view when multiplied by the ashing factor gives
the corrected area of the field.
2.7 EM Data Analysis
2.7.1 Checking Data on Key Punch Cards
Key punch cards are checked by obtaining a printout of all
cards as illustrated in Table D-3 of Appendix D. This printout
helps in detecting key-punching errors by comparison with the
coding forms.
2.7.2 Separating Very Large Sized Bundles
At present, separating bundles of fibers from the data is
done by inspection of printout of the input data. The computer
program can be modified to exclude the very large sized fibers
from the analysis.
18
-------
2.7.3 Fortran Program for Obtaining Characterizing
Parameters
Each analyzing laboratory can develop its own computer
program to facilitate statistical analysis and to obtain the
necessary characterizing parameters. One Fortran program
called CONLAB was specially developed at IITRI for obtaining
several important characterizing parameters. The listing for
this program is given in Appendix C. The program gives char-
acterizing parameters for each TEM grid used.
2.7.4 Printout of Results on each TEM Grid
A typical printout of results on each TEM grid (for the
data in Table D-3) is given in Tables D-4 and D-5. The para-
meters shown are:
Fiber counts for each category
Fiber concentration per cm2 of filter
Fiber concentration per m^ of air
Mass concentration per cm^ of filter
Mass concentration per m3 of air
Length (ym) Mean
Std. Deviation
Diameter (ym) Mean
Std. Deviation
Volume (ym)3 Mean
Std. Deviation
2.7.5 Summary of Results for a Typical Air Sample
Summaries of the results are obtained using relevant
quantities from the printouts in Table D-4 and D-5. Shown
in Table D-6 are the characterizing parameters for all fibers
and for chrysotile fibers.
2.7.6 Precision of TEM Estimates
When more than one TEM grid is used, it is possible to
obtain the mean values and 95% confidence levels on the means.
This is done for each important parameter. The method consists
of obtaining the mean, x, the standard error of the mean, SEm,
19
-------
and t-value [6] (0.025, n - 1) for n - 1 degrees of freedom,
where n = number of TEM grids examined and hence n replicates
available. The 95% confidence limits are given by x + t • (SEm).
In the illustrative case, Table D-6, the following four
parameters are given-.
6 3
1. Fiber number concentration of all fibers, 10 /m of air
-9 3/3 £
2. Volume concentration of all fibers, 10 cm /m ox axr
6 3
3. Fiber number concentration of chrysotile, 10 /m of ai.r
4. Mass concentration of chrysotile fibers, yg/m of air
The t-value decreases sharply with greater replication.
For example, t = 12.7 for n = 2 and decreases to 4.3 for n = 3
and to 2.77 for n = 5 and so on. The standard error of the mean
also decreases with greater replication. Hence, to increase the
precision of the TEM estimates, 3 or 4 replicates per sample
should be analyzed.
2.7.7 Analyzing Data on Very Large Bundles of Fibers
Fiber bundles should be reported separately as the number
concentration of large bundles or fiber aggregates (greater than
3 3
1 vim each) per m of air. In general, these are few and these
computations can easily be done using a desk calculator.
No attempt is made to compute either the volume or the
mass of bundles because of the large uncertainty in assigning
dimensions to aggregates.
2.8 Ashing, Sonification, and Reconstitution
Some air samples (especially samples collected over
several hours) may contain high levels of organic contaminant.
This organic matter obscures the fibrous particles, and inter-
feres with the proper counting, sizing, and identification.
Such samples should be ashed and reconstituted as follows.
A section of known area (e.g., 1 cm x 1 cm) is cut from
the polycarbonate filter used to collect the air sample and
20
-------
placed in a clean glass vial (30 mm diameter x 80 mm high).
The membrane is positioned such that the particle collection
side (shiny side) faces the glass wall. The vial is placed
in an upright position in a low-temperature asher. Using
manufacturer's instructions, vacuum is obtained and the filter
is ashed at 40 watts power in oxygen plasma. Oxygen is admitted
at 2 psi pressure. Though the membrane vanishes in about a
half-hour, the ashing is continued for about 3-4 hours to
ensure complete ashing. The ashing chamber is allowed to slowly
reach atmospheric pressure. The vial is removed and 10 ml of
filtered distilled water containing 0.1 percent filtered Aerosol OT
is added. The vial is placed in a 100 ml beaker containing 50 ml
of water, and this beaker is placed in a low-energy, ultrasonic
bath. Ultrasonic energy is applied for 15 minutes to disperse
all of the ash.
A 25 mm diameter filtering apparatus is assembled with a
25 mm diameter, 0.1 ym pore size polycarbonate filter with
5 um pore size cellulose ester filter backing on the glass frit.
Suction is applied and the filters are recentered if necessary.
The filter funnel is mounted and the suction is turned off.
Two ml of distilled water is added to the funnel followed by
the careful addition of the water containing the dispersed ash.
Suction is applied to filter the sample. The vial should be
rinsed with 10 ml of 0.1 percent Aerosol OT at least twice and
the contents carefully transferred to the filtration funnel
before the funnel goes dry. At the end of filtration, the
suction is stopped. The filter is then dried in still air and
stored in a disposable petri dish. After drying, the filter is
ready for carbon-coating (see Section 2.3) and transfer to the
grid (see Section 2.4).
The effective area of the redispersion filter and the
area of the section cut for ashing from the original membrane
must be taken into account when computing the fiber concen-
tration, etc., in the TEM data analysis.
21
-------
2.9 Limits of Detection
The minimum detection limit of the electron microscope
method for the enumeration of airborne asbestos fibers is
variable and depends upon the amount of total extraneous
particulate matter in the sample and the contamination level
in the laboratory environment. This limit also depends on the
air sampling parameters, loading level, and the electron micro-
scope parameters used.
In the provisional method proposed, 100 fields, each
— fi 9
field with an-area 0.18 x 10" cm are scanned. Assuming that
a fiber count has an accuracy of + 1 fiber then the detection
limit is
Detection Limit = —— • ^rea Fi-lter (cm )
100 0.18 x 10~b (cm )
1
Vol. of Air (m )
In an alternate method (for very light loading samples) when
four, full grid openings are scanned, each grid opening with
/ 0
an area of 0.72 x 10 cm , the detection limit is
2
~ _ . . T • •*. 1 Area of Filter (cm )
Detection Limit = — • ±±-7 —-
4 0.72 x 10"* (cm )
1
Vol. of Air (m^)
Table 3 gives an indication of the magnitude of the detection
limit, calculated for the high-volume sampler method. It is
seen that the minimum detection limit is lower for very dilute
samples. Examining full grid openings leads to a lower value
of minimum detection limit because of the large area scanned,
as compared with the field of view method. With a given
sample, the detection limit can be lowered as low as desired,
but the experimental effort required also increases. The
22
-------
Table 3
MINIMUM DETECTION LIMIT USING HIGH-VOLUME AIR SAMPLER
Full Grid Opening**
Vol. of Air Field of View Method* (1 fiber in
Sampling Sampled (1 fiber in 100 fields) 4 grid openings)
Duration million fibers/m^ million fibers/m^
Point
Source \ hr 21 1.07 0.07
Near
Source 2 hr 84 0.27 0.02
Distant
Source 8 hr 336 0.067 0.005
* 1 Fiber 406 cm^ 1
Detection Limit =
100 fields 0.18 x 10"^ cm /field Vol. of Air Sampled,
** ^ ^ T • . 1 Fiber 406 cm^
Detection Limit = •
4 Grids 0.72 x 10"^ cm^/grid Vol. of Air Sampled,
-------
guidelines of using 100 fields of view or four full grid
openings represent a judicious compromise, between a reason-
able experimental effort and a fairly low value of the detec-
tion limit. Also, using two or more TEM grids will reduce
the detection limit further and also improve the precision of
the detection limit.
3. PREPARATION OF BLANKS
Even after taking utmost precautions of cleanliness to
avoid asbestos contamination, one cannot rule our the possi-
bility of some contamination. It is a good practice to check
contamination periodically by running blank samples.
A blank sample may consist of a clean filter, subjected
to all the processing conducted with an actual air sample.
These may include ashing, resuspension, redeposition, carbon
coating, transferring to TEM grid, and TEM examination.
24
-------
REFERENCES
1. "Tentative Method of Analysis for Suspended Particulate
Matter in the Atmosphere (High-Volume Method) 11101-01-70T",
Methods of Air Sampling and Analysis, Intersociety
Committee, American Public Health Association, 1015 Eighteenth
St. N.W. , Washington, DC, 1972.
2. Recommended Procedures for Sampling and Counting Asbestos
Fibers; Joint AIHA-ACGIH Aerosol Hazards Evaluation Committee,
American Industrial Hygiene Association Journal, Vol. 36,
No. 2, pp. 83-90, 1975.
3. M.A. Jaffe. In Proceedings Electron Microscope Society of
America, Toronto, Sept. 1948.
4. R.L. Clark and C.L. Ruud. Transmission Electron Microscopy
Standards for Asbestos. Micron, Vol. 5, pp. 83-88, Pergamon
Press, 1974.
5. P.K. Mueller, A.E. Alcocer, R.Y. Stanley and G.R. Smith.
Asbestos Fiber Atlas. U.S. Environmental Protection Agency
Publication No. EPA-650/2-75-036, April 1975. National
Technical Information Center, Springfield, Va.
6. R.A. Fisher and F. Yates. Statistical Tables for Biological,
Agricultural and Medical Research Workers. Table IV,
6th Ed., Stechert-Hafner, Inc., New York, 1964.
25
-------
Appendix A
INSTRUMENTATION AND SUPPLIES
26
-------
Appendix A
INSTRUMENTATION AND SUPPLIES
A. INSTRUMENTATION
1. Transmission Electron Microscope
A transmission electron microscope should be capable of
100 kv of accelerating voltage, 1 nm resolution, and a magni-
fication range of 300 to 100,000X. The instrument should be
capable of selected area electron diffraction analysis on
areas 300 nm diameter. The fluorescent screen should have
either a millimeter scale, concentric circles of 1, 2, 3,
and 4 cm radii, or other devices to estimate the length and
width of fibrous particles. All modern transmission electron
microscopes meet these requirements.
2. Vacuum Evaporation
A vacuum evaporator is required for depositing a layer
of carbon on the polycarbonate filters and for preparing
carbon-coated EM grids. The evaporator should have a turn-
table for rotating the specimen during coating.
3 . Low-Temperature Plasma Asher
A low-temperature plasma asher is required when the
quantities of organic matter in the air sample are very high
and interfere with the detection and identification of
asbestos. Oxygen should be used for plasma ashing. The
sample chamber should be at least 10 cm diameter, so that
glass vials can be positioned vertically (e.g., Plasmod,
Tegal Corporation, Richmond, Ca. or equivalent).
B. SUPPLIES
1. Jaffe Washer: For dissolving polycarbonate filters.
This item is not available commercially. The assembly is
described in Section 2.4 and illustrated in Figure 1.
27
-------
2. Filtering Apparatus: 47 ram filtering funnel
(e.g., Cat. No. XX1504700, Millipore Corp. Order Service Dept.,
Bedford, Ma. 01730). 25 mm filtering funnel (Cat. No. XX1002500,
Millipore Corp. Order Service Dept., Bedford, Mas. 01730).
These are used to filter dispersed ash samples.
3. Vacuum Pump: A vacuum pump is needed to filter ash
suspensions. It should provide up to 20 in. of mercury. Such
vacuum pumps are available from any general laboratory supply
house.
4. EM Grids: 200-mesh copper or nickel grids with car-
bon substrate are needed. These grids may be purchased from
manufacturers of electron microscopic supplies (e.g., Cat.
No. 1125, E.F. Fullam, Schenectady, NY) or prepared by standard
electron microscopic grid preparation procedures. Finder grids
may be substituted and are useful if the re-examination of a
specific grid opening is desired (e.g., Cat. No. 1458, H-2
Londoni 200 Finder grids, E.F. Fullam, Schenectady, NY or Cat.
No. 175420 200 mesh carbon-coated nirlypl grids, Ladd Research
Industries, P.O. Box 901, Burlington, Vt. 05401).
5. Membrane Filters: Polycarbonate
(g)
(a) 47 mm diameter, 0.4 um pore size Nuclepore^
membranes or equivalent.
(b) 37 mm diameter Nuclepore^ membranes for use
with the personal dust samplers.
(c) 25 mm diameter, 0.4 um pore size Nuclepor^
membranes or equivalent to filter dispersed
ash suspension.
(d) 20 cm x 25 cm, 0.4 pm pore size Nuclepore^
membranes or equivalent for collecting air
samples using the high-volume sampler.
6. Membrane Filters: Cellulose acetate (to be used
as backing filters)
(§)
(a) 47 mm diameter, 5.0 ym pore size Millipore^
or equivalent.
28
-------
(b) 37 mm diameter, 5 ym pore size Millipore®
filters or equivalent for use with personal
dust samplers.
(c) 25 mm diameter, 5 ym pore size Millipore^
filters or equivalent.
(d) 20 cm x 25 cm, 5 ym pore size Milliporew
filters or equivalent for use with the
high-volume sampler.
7. Air Samplers:
(a) High-volume sampler, see reference 1
(e.g., Sierra Instruments, Model 305,
3756 N. Dunlap St., St. Paul, Mn. 55112 or
equivalent).
(b) Personal dust sampler, see reference 2
(e.g., MSA Gravimetric Dust Sampling Kit,
MSA Co., Pittsburgh, Pa. 15208 or equivalent).
8. Glass Vials: 30 mm diameter x 80 mm long; for
holding filter during ashing. 50 ml beakers can be used
instead of vials.
9. Glass Slides: 5.1 cm x 7.5 cm; for support of
filters during carbon evaporation.
10. Scalpels: With disposable blades and scissors.
11. Tweezers: Several pairs for the many handling
operations.
12. Doublestick Cellophane Tape: To hold filter section
flat on glass slide while carbon coating.
13. Disposable Petri Dishes: 50 mm diameter and 100 mm
diameter for storing membrane filters.
14. Static Eliminator: 500 microcuries PO-210.
(Nuclepore Cat. No. V090POL00101) or equivalent. To eliminate
static charges from membrane filters.
15. Carbon Rods: Spectrochemically pure, 3.0 mm
diameter, 4.6 mm long with 1.0 mm neck. For carbon coating
29
-------
(Cat. No. 42350, Ladd Research Industries, P.O. Box 901,
Burlington, Vt. 05401 or equivalent).
16. Ultrasonic Bath: (50 watts, 55 KHz). For dis-
persing ashed sample and for general cleaning.
17. Graduated Cylinder: 500 ml
18. 10 yH Microsyringe: For administering drop of
solvent to filter section during sample preparation.
19. Carbon Grating Replica: 2160 lines/mm. For cal-
ibration of EM magnification (e.g., Cat. No. 1002, E.F. Fullam,
Schenectady, NY or equivalent).
20. Specimen Grid Punch: For punching 3 mm diameter
sections from membranes (e.g., Cat. No. 1178, E.F. Fullam,
P.O. Box 444, Schenectady, NY 12301 or Cat. No. 16250, Ladd
Research Industries, P.O. Box 901, Burlington, Vt. 05401).
21. Screen Supports: Copper or stainless steel;
6 mm x 6 mm, 60-100 mesh. To support specimen grid in Jaffe
washer.
22. Filter Paper: S&S #589 Black Ribbon or equivalent
(5*5 cm circles). For preparing Jaffe washer.
23. Chloroform: Spectro grade, doubly distilled. For
dissolving polycarbonate filters.
24. Acetone: Reagent grade or better. For cleaning
the various tools.
25. Asbestos: Chrysotile (Canadian), crocidolite,
amosite. UICC (Union International Contre le Cancer) standards.
Reference asbestos samples available commercially (e.g., Duke
Standards Company, 455 Sherman Avenue, Palo Alto, Ca. 94306 or
Particle Information Service, 600 South Springer Road,
Los Altos, Ca. 94022 or equivalent).
26. Petri Dish: Glass (100 mm diameter x 15 mm high).
For modified Jaffe washer.
30
-------
27. Cleanser: Alconox, Inc., New York, NY 10003 or
equivalent. For cleaning glassware. Add 7.5 g Alconox to
a liter of distilled water.
28. Aerosol OT: 0.1% solution (Cat. No. So-A-292,
Fisher Scientific Co., 711 Forbes Ave., Pittsburgh, Pa. 15219).
Used as a dispersion medium for ashed filters. Prepare a
0.17o solution by diluting 1 ml of the 10% solution to 100 ml
with distilled water. Filter through 0.1 um pore size poly-
carbonate filter before using.
29. Parafilm: American Can Company, Neenah, Wi. Used
as protective covering for clean glassware.
30. Pipettes: Disposable, 5 ml and 50 ml.
31. Distilled or Deionized Water: Filter through 0.1 ym
pore size polycarbonate filter. Used for making all reagents
and for final rinsing of glassware, and for preparing blanks.
31. Storage Box for TEM Grids: Cat. No. E-0174 Grid
Holders, JEOL U.S.A., Inc., 477 Riverside Avenue, Medford,
Mass. 02155 or equivalent.
33. Squeeze Bottles: For keeping double-filtered dis-
tilled water and 0.1 percent Aerosol OT solution.
34. Welders Protective Goggles
31
-------
Appendix B
MAGNIFICATION CALIBRATION
32
-------
Appendix B
MAGNIFICATION CALIBRATION
(1) Align the electron microscope using the instruction
manual provided by the manufacturer.
(2) Insert mag-calibration grating replica (with 54864
lines per inch, or 2160 lines per mm, e.g., Cat. No. 1002,
E.F. Fullam, Schenectady, NY) in the specimen holder.
(3) Switch on the beam, obtain the image of the replica
grating at 2O,000X magnification (or the magnification at which
the asbestos samples will be analyzed) and focus.
(4) If the fluorescent screen has scribed circles of
known diameters, proceed as follows. Using stage control,
align one line tangentially to circumference of one circle.
Count the number of lines in a diameter perpendicular to the
lines. In most cases, the other end of the diameter will be
in-between the N*"*1 and N + I1"*1 line. You can estimate the
fractional spacing by eye. Alternatively, one can estimate
the separation between lines using the scribed circles.
(5) If X line spacings span Y mm on the fluorescent
screen using this grating replica, the true magnification is
given by
M = Y x 2160
X
The readings should be repeated at different locations of the
replica and the average of about 6 readings should be taken
as the representative or true magnification for that setting
of the electron microscope.
33
-------
Line Spacings ram on Screen Magnification
* Y . _ H
95 83 18871
93 80 18580
70 60 18514
8.8 80 19636
90 80 19200
9 0 80 19200
Average 19000
On most"electron microscopes with large (18 cm dia.)
fluorescent screens, the magnification is substantially con-
stant only within the central 8-10 cm diameter region. Hence,
calibration measurements should be made within this small
region and not over the entire 18 cm diameter.
34
-------
Appendix C
LISTING FOR THE FORTRAN PROGRAM CONLAB FOR
OBTAINING CHARACTERIZING PARAMETERS
35
-------
Appendix C
LISTING FOR THE FORTRAN PROGRAM CONLAB FOR
OBTAINING CHARACTERIZING PARAMETERS
C PROGRAM CONtAB
C ANALYZE FIBER AND MASS CONCENTRATIONS
C
REAL SUMX(7i6)|SUMX2C7.6)tCONCT(fc),C0NMASC6),V0LCTC6)»VOLMAS(fc)
RCAU FIBCT(t>)»QTY(7j»DEN(2).S0£VC7»6)»SLDEVC7»6)»GMN(7»6)
RCAL CVAR(7»6)«MEAN(7«fc)»MEAN2C7»6)
DATA I»ICT »PI/1 »0»3, 1(1159/
DATA DEN/2.6*3.0/
C OTYdJ s LENGTH
C OTV(2) s DIAH
C OTY(3) s MASS OR VOL
C OTV(60
LCASEsICASE
LLABelLAB
LFIL»IPIL
LPUNalPUN
00 0B0 1=1ib
FI*CT(X)=0.0
VOLCT(I) = 0.0
VOLHAS (I)eO.O
C0NCTtI)=0.O
CONMAS(I)=0,0
00 Ofltf J=1»T
SDEVCJ»I)=U.O
SLOCV fJ»1)eO« 0
CV»«(J.1)30,0
QTVCJJaO.O
•,i:an(J«s)3o,o
MCAN2( J.n=0.0
SUMX(J.I)=0.0
SUMx2(J»I)=O.0
O80 CONTINUE
GOTO 1101 •
t«0 PL*AD(5tll0»ENDsl90) IGWI i>* T T-' ¦ I K SE«; • IC SE-'J. 01 AM* »LFN * IOUT •
*INFIH» JLA«. IFILf IPUNtX^A'"-. •XAS'<,XVO|.»TAREA»ICASE
110 POHHAT (T2,2l3.1U,2Ffe,n, U. r". -X . : i, 1 X. .<1112X ,2!- 7 ,1.3F5. 1 ,5X*12)
IF CCTCASE.NC.LCASEJ.nR.CTU V NK.I.LAH)
* .OR.CIFIL.NE.LFILJ.0S. (IKW •,:.!L.LPUN) )
* GOTO 200
1101 4V0l=XV0L
F1LAR»TAREA
JLAU=ILAB
jpun=ipun
JFIL=IFIL
IF CCIGRID.EQ.LGRIDJ. AND.(IFLD.EQ.LFLO)) GOTO 1110
TOTAR=TOTAR+AREA»XA5H»l,OE-6
WRITE (6*1102)
1102 FORMAT CI32X)
LCT=LCT+2
LFLO=IFLO
36
-------
Appendix C (continued)
LGRID=IGRID
1110 IFCLCT.LE.5in GOTO 1112
WRITE (6*1111) ILAB»IFIL»IPUN»LCASE
1111 FOPMATt'lt.'IUX»tFIBER AND MASS CONCENTRATION Ifl5X»iL*B »tll»
*« 5AMP l»Ilil GRID I.I2.I CASE i»I2/
*50X.'DATA LIST I//
*1X.IFIB*SEQ FIELD FLD-SEQ DIAMI»6X«
*'LENGTH OUT-COO FIP-COD FLD-MAG ».
* IFLD«AREA ASH»MAG VOL FILT^AREAI/)
LCTsO
1112 IF (INFIB.EQ.O) GOTO 1120
IF 10s INF IB
IF((INFIB.GE.2) .AND.(INF IB.LE.5)) IFIB»INFIB+l
IF(INFIB,E0.5) IFIBs2
iFClNFIB.GE.b) IFIB=5
1120 WRITE(6»1113) ICSEQ.TFLD«IFSEa.DIAM,ALENfIOUTiINFIB»XMAG»
*ARLA«XASH.XV0L«FILAR
1113 FORMAT(3X»I4,3X»I3.5X,i3,2(5X,F6.2)»3(7X»It)»
*3(5X»F7,3)«2(4XiFS.1))
lct=lct*i
112 IF(iFSEQ ,EO ,0) GOTO 100
IF (I0UT.E0.2) GOTO 115
FIBCT(IFIB)=FIBCT(IFIB)+1.0
GOTO 117
115 FIPCT(IFie)=FIBCTCIFIB5+0,5
ALL"n = ALEN»2.U
117 ALL"N = ALEN/XMAG
DIAM=DIAM/XMAG
0TY(1)=ALEN
QTY(2)=DIAM
(5TY(3)=PI*ALEN#DIAMiMX (1.6)+Su"X c I, inn)
SUXX2(T»6)=5UMX2( I» 6)+SU'^X2( 11 IFI«)
205 CONTINUE
FIPCT(6)=T0TCT
DO 599 IF IB= 1»6
IF (FIBCT(IFIB).EO.O.O) GOTO 599
CONCT(IFIB)=FI9CTtIFIB)/TOTAR
V0LCT(IFIB)SC0NCT
-------
Appendix C (continued)
150 270 l = t»3
SOI-VCI# IFIR)=SDRT(ABS(MEAN2(I»IFIB)i»
* IFIB))))
SLDEV(I»IFIB)5SQRT(ABS(MEA)>l2(I + 3f IF IB)"
* (MEAN(1*3»IFIB))*(MEAN(I*3»IFIB))})
CVAH(X»IFIB)=tXf(5L0FV(IiIFlB))»l
GMN)/>
WRITE C6. 610) ( r.ONC T (i!- T 61 , 1IB= t « 6) . { VOLCT tIFIB) fIFIB«l»fc)
610 rOHMATClX. IFI5FR CO TIONi/
*1* » I (FIBERS P£f! S(j r." nF t tlTER) I . 6 ( E I 2 .« . 3X) /
* 1 X. i (FIBERS PER C-U- i'.Tfcl Or Alh) I . 6{£ I 2.«. 3X)/)
WRITE (<>f 613) (CONe Ar I 1 F>; , I f 1 :> -• 1 , 5) » ( VOUM A S (IFI BO . I F IBsl, 2)
615 FO»MATCiX»»MAS!> CO'; rPi rm . :,X. i PERCENT TOTAL FIBERS!/
*1X.I(GPAMS PF« SQ i: ¦ F I! 7 R R) I f
*2X.2(C1 ? ,'U3X ) • Ml- :¦¦ . ! X. 1 •< I , 7X) /
* 1 X»itGRAMS PPK Mia ' I~" ¦ AIR)111X» 2 (112. 4» 3X ) /)
wRiTE(6f6?0) C-'t.Af.f t; iFir-).: -1e -1.6)»
* CSOCV C 1 . IFIU) . I- It!--
*(MCAN(«iIFIB)»TP I ? " ¦ : ¦ )»
*(GMN C1 .1FI(Vj , if- ,
*fCVAR( 1 I IFItJ) < I ¦ ie ¦!.'>)
6.10 FORMATClXt ILEM5TH AN: « : IX . 6 (F12, <1 f 3X) /
*tx. I (MICRONS) Sio I)-I , ex ¦ I? , <1 .3X) /
* 1 IX I i MEAN LOG I |7'«-V. ! ? . 1 < -n /
Ml*»'GfOM MN ! >7X i : : 1 ? ,0 > V<) /
* 1 1 X t I CnCF V A ri ' •7X»'-(* 12
WR I TE ( & i 62'j) C'tA'.i.-. iFi--W r.rI<=-l t6J*
*(S0EV(2»IF IB)iIF IB*It6)»
*(MEAN(5.IF1B)iIFIB=l»b)i
*(GMN(2.IF IB)iIF IBs 1,b).
*(CVAR 12¦I FIB).IFIB=1.6)
625 FORMATCl X» iDMMtTfcR Hf AN 1,11 * , 6 (F12. 4»3X) /
*1X.I(MICRONS) SID DEVI . 8X»6{F 12,fl .3X) /
* 11X .1 MEAN LOG'»7X»6(Fi2.4»SX>/
*11X«1GEOH MN it7Xf6(Ft2.«.3X)/
*11X»'COEF VA«>»7Xf6(F12.a,3X)/)
WRITE(6i&30) (MtAN(3tIFIB)»IFIB*116)»
*(Sr)EV(3. IFIB) < IHB=116) »
*(MlTAN(6.IFIB).Irla=li6)»
*(6MN(3.IFIBJiIFirj=N6)i
*(CVAR£3. IFIB) . IHS=1 16)
630 FORM AT (1X t i VOi. IIHE MEAN I , 15X » b (E12.413X> /
* 1X.KCUB CM) 510 DEVI , 12X » 6 ( E 12 . 4 • 3X) /
* 11 yf 'MEAN LOG I .7X.6(F12,
-------
Appendix D
ILLUSTRATIVE TABLES
39
-------
Table D-l
ELECTRON MICROSCOPE METHODS FOR ASBESTOS DATA ENTRY FORMAT, PER FIBER
Cols.
Description of Coding-Sheet Field
Permissible Values"
1-2
EM grid opening ID
01 to 99
3-5
EM field ID
001 to 999
6-8
Sequence no. of fiber within field'"1'
0 to 999
9-12
Cumulative sequence no. within sample"*
0 to 9999
13-18
Diameter in mm (do code decimal point)
0.0 or greater
19-24
Length in mm (do_ code decimal point)
0.0 or greater
26
2 if fiber extends beyond perimeter
0, 2
28
1 if a fiber bundle
0, 1
30
Fiber type
1, 2, 3, etc.
32-36
Case identification:
Col. 32 - lab
0 to 6
33 - filter - sample
1, 2, etc.
34 - punch - grid
1, 2
35 - instrument type
1, 2, 3
36 - operator within lab
1, 2
37-43
Magnification in multiples of K = 1000
(do code decimal point)
1.0 to 99.9
44-50
Area of EM field identified in cols. 3-5,
— 6 2
in 10 cm (do code decimal point)
0.001 to 999.99
51-55
Ashing factor
0.1 to 10
56-60
Volume of air sampled in m
1.0 to 100.0
61-65
Effective area of the original membrane
?
m cm"
1.0 to 999.9
71-72
Data set code
1 to 99
* Right-justify numbers in all fields unless a decimal point is
entered. A blank is equivalent to a zero.
** If no fibers are observed in a field, write a one-line record with:
(1) 0 entered for sequence no. of fiber in field and for cumulative
sequence no.
(2) diameter and length fields and also columns 26, 28, and 30 blank
(3) grid opening ID, field ID, case ID, magnification, and area,
entered as usual.
40
-------
Table D-2
ILLUSTRATION OF FORTRAN CODING FORM SCHEME
1
1
1
1.
20 .
1
31111
17 .
.182
1.0
9 . 2
406.5
1
2
2
• 25
7 .
2
2
1
3
. 5
17 .
2
i j
2
2
4
!•
10 . j
1
2
3
5
1-
00
I—1
1
i
2
4
6
. 75
22 . |
1
i
i i
2
5
7
12 . j
1
f
)
2
6
8
• 5
10.
3
,
i
;
3
I
9
. 25
24 . 1
1
i
I
;
3
2
10
. 75
18. '
2
t
t
;
l
3
3
11
1.
10 . |
1
i
|
3
4
12
1.
a. :
1
(
3
5
13
. 25
10. ;
3
j
4
1
14
. 25
6 .
!
1
1
4
2
15
. 25
*
20. ;
2
4
3
16
. 5
5.
3
5
1
17
2.
65.
2
1
5
2
18
1.
10 . i
2
5
3
19
. 5
4 .
3
6
1
20
1.
30.
1
6
2
21
2.
32 .
1
7
1
22
1.
25.
1
8
1
23
. 5
5.
2
9
1
24
. 25
6.
2
9
2
25
1.
30.
2
1
-------
Table D-3
COMPUTER PRI'-ITOUT OF DATA CARDS
1*2 3
7 8 9 10
1L
12
13
14
15
at
C
a>
.5
CO
Q>
•rl
nj
&
cx
U<
O
3
ai
o
C
Z
U-l
•H
•H
O
D-
-r1
cr
U
g
a
<4-1
a
M
CO
3
u
o
* See page 44 for detailed explanation of the column headings.
16
CJ
CM
TJ £
u
u
rH a
o
at
0J
0)
i-i
W>
¦HvO
CO
PtH |
u
a)
•H
CC
o
o
j-j
n
0J —i
4J
<
ffl
00
c
u
¦H £
c
n
O >4
<13
<
CU
O
X
t*4
>
<4-1
Q
*4-1 -O
4-t
o
M
c o
o a)
&o
o
¦r-I
¦ 0.
aj
i—i
aj
w
U '
0)
U-t
i—(
-O
o
J-f UU
m
o rc
U-l
o
c
u
CO X
cn
a
o
H
1
1
1
2
1
2
1
1 .
20.
1 31111
7. .181
.0
9.2
408.9 3
2
,25
7.
2 11111
7. .188
.6
9.2
406.9 1
£
1
2
3
.5
17.
2 31111
7. .i«2
.0
9.2
406.9 3
1
2
a
1 ,
to.
1 31111
7. .18?
.0
9.2
406,9 3
1
2
1
5
1 ,
IB.
1 31111
7. .182
.0
9.2
406.5 I
1
o2
4
06
.75
22.
1 31111
7. •182
.0
9.2
406.9 3
I
02
5
07
1 .
12.
1 31111
7, .182
.0
9.2
406.5 3
1
02
b
oe
10.
3 31111
7. .Ill
.0
9,2
406,9 3
1
03
1
09
.25
24.
1 31111
7. .162
.0
9.2
486.5 J
1
03
2
10
.75
IS.
2 31111
T. .18?
.0
9.2
406.9 3
I
03
3
1 1
1.
10.
I 31111
7. .1(2
.0
9.2
406.9 3
1
03
a
12
1.
B.
1 31111
7. .1>2
.0
9,2
406.9 3
J
03
<3
13
.25
^ 0 .
3 31111
T. .188
.6
9.2
406.9 3
I
0«
1
14
.25
A •
1 31111
7. .182
.0
9.2
406.5 3
L
00
2
15
.25
20.
2 31111
7. .182
.0
9.2
406.9 3
1
0"
3
16
.5
5.
J 31111
7. .182
.0
9.2
406,5 1
I
05
1
17
65.
2
1 31111
7. .182
.0
9.2
406.9 3
1
05
2
IB
1 .
10.
2 31111
7. .182
.0
9.2
406,9 3
1
05
3
19
.5
4.
2 31111
7. .162
.0
9.2
406.9 3
1
0b
1
20
I •
30.
1 31111
7. .182
.0
9.2
406.9 3
I
06
2
21
33.
1 31111
7. .182
.0
9.2
406.9 3
1
07
1
22
1 a
25.
1 31111
7. .181
.0
9.2
406.9 3
1
0B
1
23
.5
5.
2 31111
7. .182
.0
9.2
406.S 3
1
09
1
21
.25
fr «
2 31111
7. .182
.0
9.2
406.5 3
1
9
2
25
1 *
50.
2
1 31111
7. .182
.0
9.2
406.9 3
1
10
1
2e
1 «
1 6 •
2
1 31111
7. .182
.0
9.2
406.5 3
1
10
2
27
1 •
6 ¦
2
1 31111
7. .162
.0
«.2
406,9 3
1
10
3
26
1 •
12.
2
1 31 11 t
7. .162
.0
9.2
406,9 i
1
10
a
29
.25
10.
2 31111
7. .182
.0
9.2
406.5 3
1
10
s
30
.25
U.
3 31111
7. .182
.0
9.2
406.9 3
2
11
1
31
I •
B a
1 31111
7. .182
.8
9.2
406.5 3
2
11
2
32
1 •
6 •
1 31111
7. .182
.0
9.2
406.9 3
2
11
3
33
.5
5.
2 31111
7. .162
.0
9.2
406.5 3
2
11
4
3a
J •
ft 1
2
2 31111
7. .182
.0
9.2
406.9 3
2
12
I
35
1 »
4.
1 31111
7. .182
.0
9.2
406.9 3
2
12
2
36
.2
4.
2 31111
7. .I82
.0
9.2
406,5 3
2
12
3
37
.25
5.
3 31111
7. .182
.0
9.2
406.9 3
2
13
1
38
1 •
IB.
1 31111
7. .182
.0
9.2
406,5 i
2
13
2
39
.2
12.
3 31111
7. .182
.0
9.2
406,9 3
2
1«
1
uo
1 •
20.
I 31111
7. .1 at
.0
9.2
406.9 3
2
15
1
ul
1 •
IB.
1 31111
7. .182
.0
9.2
406.9 3
2
15
2
"2
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12.
2 31111
7. .182
.0
9.2
406,5 3
2
15
3
13
.25
«.
2 31111
7. .182
.0
9.2
406.5 3
2
15
u
uu
.25
3.
3 31111
7. .182
.0
9.2
406.5 3
2
lb
1
18
.5
5.
2 31111
7. .182
.0
9.2
406.9 3
2
16
2
16
.2
3.
3 31111
7. .182
.0
9.2
406,9 3
2
IT
1
«7
1.
25.
2
1 31111
7, .182
.0
9.2
496,9 3
2
17
2
48
1.
20.
2
1 31111
7. .182
.0
9.2
404,9 3
2
17
3
49
.5
61
2
1 31111
7. .102
.0
9.2
406.9 3
2
17
4
50
.75
B.
2 31111
7. .182
.0
9.2
406.5 3
2
17
5
51
.1
12.
3 31111
7. .182
.0
9.2
406.5 3
2
I*
1
52
3«.
\ 31111
7. .162
.0
9.2
U0fc.«; 3
2
IB
2
53
1.5
I.
1 31111
7. .18?
.8
9.2
406.9 3
2
1«
3
5a
.2
B.
2 31111
7. .182
.0
9.2
406.9 3
2
IB
u
55
1.
10.
2
1 31111
7. .182
.0
9.2
406.9 3
42
-------
Table D-3 (continued)
1*
2
3
4
5
6
7 8
9
10 11
12
13
14
15
2
t«>
t
Si
.5
13.
1
31111 17.
.182
.0
9.2
406
2
19
2
57
.25
6.
a
31111 17.
.182
.0
9.2
406
2
19
3
56
.25
12.
3
31111 17.
.181
.0
9.2
406
2
20
I
59
.1
8.
2
31111 17.
.182
.0
9.2
406
2
20
2
60
1.5
25.
1
31111 17.
.182
.0
9.2
406
2
20
3
61
.5
27.
2
2
31111 17.
.182
.0
9.2
406
2
20
4
62
.25
10.
2
31111 17.
.182
.0
9.2
406
3
21
1
63
.75
15.
1
31211 17.
.182
.0
9.2
406
3
21
2
64
.25
6 •
2
11211 17.
.182
.0
9.2
406
3
21
3
65
.5
15.
2
31211 17.
.182
.0
9.2
406
3
21
a
66
.25
3.
3
31211 17.
.162
.0
9.2
406
3
22
1
67
.5
61
a
1
31211 17.
.182
.0
9.2
406
3
22
2
60
.5
10.
5
31211 17.
.182
.0
9.2
406
3
22
3
69
.25
5.
3
31211 17.
.182
.0
9.2
406
3
23
1
70
.5
7.
1
31211 17.
.182
.0
9.2
406
3
23
?
71
.25
12.
2
3)211 17.
.182
»o
9.2
406
3
23
3
72
.2
3.
3
31211 17.
.182
.0
9.2
406
3
24
1
73
1.
28.
1
31211 17.
.182
.0
9.2
a06
3
2«
2
74
1.
30.
1
31211 17,
.182
.0
9.2
406
3
25
1
75
1.5
6.
1
31211 17.
.182
.0
9.2
406
3
25
2
7*
.25
8.
3
31211 17.
.162
.0
9.2
406
3
26
t
77
.75
13.
1
31211 17.
.182
.0
9.2
406
3
26
2
78
.5
If.
2
31211 17.
.181
.0
9.2
406
3
26
3
79
.25
5.
3
31211 17.
.182
.0
9.2
406
3
27
1
B0
.5
26.
1
31211 17.
.182
.0
9.2
406
3
28
1
PI
.5
15.
2
31211 17.
.162
.0
9,2
406
3
29
1
62
2.
17.
1
31211 17.
.182
*0
9.2
406
3
29
2
83
.25
3.
3
31211 17.
.162
.0
9.2
406
3
30
1
»4
1.
3.
3
1
31211 17.
.182
.0
9.2
406
3
30
2
AS
.5
4.
2
31211 17.
.162
.0
9.2
406
I
30
3
*6
.25
a.
3
31211 IT.
.182
.0
9.2
406
4
31
1
»7
3.
t*.
1
31211 17.
.182
.0
9.2
406
u
31
2
«e
.5
7.
4
31211 17.
.162
.0
9.2
406
a
31
3
69
.5
15.
4
31211 17.
.182
.0
9.2
406
4
32
1
90
1.5
25.
1
31211 17.
.162
.0
9,2
406
a
32
2
91
1.
15.
a
1
31211 17.
.182
.0
9.2
406
4
32
3
92
1.
10.
4
31211 IT.
.162
.0
9.2
406
4
33
1
93
1.
35.
2
1
31211 17.
.182
.0
9.2
406
4
33
2
94
.25
5.
i
31211 17.
.162
.0
9.2
406
a
34
1
95
2.
10.
2
1
31211 17.
.182
.0
9.2
406
u
34
2
96
1.
15.
2
1
31211 17.
.182
.0
9.2
406
a
34
3
97
1.
12.
4
31211 17.
.162
.0
9.2
406
a
35
1
96
2.
20.
i
1
31211 17.
.182
.0
9.2
406
a
35
2
99
2.
12.
1
31211 17.
.182
.0
9.2
406
a
35
3
100
1.
11.
4
31211 17.
.182
.0
9.2
406
4
35
a
101
1.
6 •
4
31211 17.
.182
.0
9.2
406
4
35
5
102
.5
10.
3
31211 17.
.182
.0
9.2
406
a
36
I
103
.5
13.
2
1
31211 17.
.182
. 0
9.2
406
a
36
2
1 Oil
.5
a.
4
31211 17.
.182
.0
9.2
406
4
36
3
lot
.5
10.
3
31211 17.
.182
.0
9.2
406
a
3?
I
1 "6
.5
9.
1
31211 17.
.182
.0
9.2
406
4
37
2
107
.5
5.
4
31211 17.
.162
.0
9.2
406
4
37
3
106
.25
6.
3
31211 17.
.162
.0
9.2
406
a
3»
1
109
1.
45.
2
1
31211 17.
.182
.0
9.2
406
-------
EXPLANATION OF THE COLUMNS IN TABLE D-3
u n 1 EM grid opening identification number
n 2 Identification number for the field of view
umn 3 of^view6 num^er a fiber within a given field
Column 4 -- Cumulative number of fibers counted
Column 5 -- Fiber width in mm
Column 6 - Fiber length in mm
t a" u^"nc^cates the fiber crossing the perimeter
n » hence, one that is counted as a half-fiber
Colunn 8 - A '1' indicates a bundle
Column 9 — Fiber type identification code
1 ->• chrysotile
2 ->• ambiguous
3 ^ no SAED pattern, etc.
umn 10 ^dentification. Laboratory code, sample
Srid index, type of TEM instrument
coae, the operator code, etc.
umn 11 Magnification at the TEM fluorescent screen in
multiples of 1000
Column 12 -- Area of one field of view in multiples of 10"^ cm'
Column 13 -- Ashing factor, to account for the dilution or con
j ^esulting in the ashing step. In the
procedure without the ashing step, the ashing
factor is taken as 1.0.
Column 14 - Volume of air sampled in m3
Column 15 -- Effective area of the original air filter in cm^
Colunn 16 -- Index for the data set
44
-------
Table D-4
PRINTOUT FROM PROGRAM COIJLAB CHARACTERIZING PARAMETERS PER TEM GRID
FlnE* AND MASS CONCENTH*TI0M
Sl'MMAWV
U*B i SAMPLE 1 GHID 1 CASE i
Tf 1 4L a»C* «c*,JNEt> *
r.*TA(. a^la I fi. =
fTAU FJ.«PJ rt)U'>T S
"•TAU VPl.*1R s
, u'l OU* si s
So, 5
O.e
Si» CM
Su C*
FIBcPi
CCIC mf.TE«8
r«PysoTll.t
.p-
Ui
«" I wI.I* COu^'T
if r-apsg)
11 -.t: K LP jf L'1 T M * T I H'i
(rjp(c»s »(>' s" o M' f ii iii-)
"IIITI-'X UF #1W)
>./ss ru"TF-TR*tIun
(-.•JA:4S PC ^ Sj CM OF F-ILTi.*)
(¦:!•&*$ pre r,,B MLTl.fi !1 F" M*)
26.b
.bA JS + 07
.2924 + 1)9
, 124Wt>
.b4K«?-CJb
AMPHIPOLE
.noon
.oooo
,0000
.0000
ambiguous
i*.o
NO PATTERN NON-ASRt8T0S
.4745+fl7
.2097*09
10.0
,?496+C7
.1 104 + 04
1.0
,2.r, T:
Ml* IK
1
.0000
.7152
.4471
.3529
1 ,103b
i>*:C-rf- v A*
1
.oroo
• M 73
. 7397
.0000
1.2524
" 'A T t
JV»':
. i't> 1.4
. u 0 0 0
.0279
,0162
.0147
,044b
' \ C X ^ '< S 1
ST r L/C 1/
. ooon
.0110
.0071
. 0000
.0233
' t-- a " i.nr,
-S.
o
c.
•3,9964
-4.2171
-4.219b
-3,7716
i.r.'iM
."3<>b
.000"
.0 1P4
.0147
.0147
.0230
C'-tF ^ a**
.t
, IIUOO
.92*2
,bU63
,0000
1.2BB5
ynu«.Mi;
CM)
ST,-. t'Cv
•<|- 4 f l_ 1 (.
s*
vik
.7^1 11-14
.ISbu-l*
,7i»44-17
,3 • 7 »»~ f 7
, P IJ 0 0
,0 000
.uroo
,nof>o
. o o« o
.bS^-lb
¦ OPB2* 1b
¦i7.9H(.i
.3183-16
.4293+04
• 1 OSh-15
.11 lb-15
¦ 37.2«53R
.*>620-16
.lbflb+01
.b995-l6
.0000
-37.3b3l
.5995-16
. 0000
.3b90»l«
.1 11H-13
-3B.b023
.1900-16
• 7941+ob
-------
Table D-5
PRINTOUT FROM PROGRAM COMLA3 CHARACTERIZING PARAMETERS PER TEM GRID
r C T ^ i_ A HZa S C * fJNc: r> =
T r> T A L AWCA I L r r ^ a
T r T L K IL.' F W r n gmf =
TIT *•_ VOL MMK AI« s
FIFE" ami) mA33 CQncFnTH*Tion
SU^AWY
LAS i SAMPLE 1 GHID 2 LASfc 3
40<>.5
UT.O
l.ii
St, L*
SC.. CM
f lMthS
fu«lC M t T t 8 5
r.hPTSCT ILfc
4>
cr\
rr-n.* coui,T
CFIrrtJS)
rn1:^ cmirr > twatio^
(»:rV7»S PFt. Cl OP PII T,;S3
(Flri-US Pl-R C'-'I 1C I L- K UF 1JWJ
M<5r> ru^CF'-'^AiioM
< c. - s PQP v.' C* IF FTLT[>')
(r.iUi1291+00
.5705+09
LI • (- Tw
*11m
1.79flI
• b*»»2
.6078
.3264
.5147
1.0250
{1 C rr m s )
£¦».) i>r*
1 ."2 !>rv
.i'IPJ
• onoo
.0069
.0056
.0147
.0334
cfAN lug
-3.523C
-3.526"
-3.7574
-4.1226
-3.1798
•3.6400
«(¦ )M «N
."P°5
.U?9«
.0233
.0162
.0416
,0260
CCtF VAP
3. :s U ii 0
.0000
• 3865
.3146
.4142
1.3776
\ 'H.'.-T
trut ri)
~Fl»'
ST ") i-'Fv
tKak. lijh
r,f nM Hij
c0r f- va«
.ou2»- 1«
¦"1.75'3
.7373-ia
,12I<' + U9
.3997-15
. r o c o
•35^59
.3997-15
.^OPC
.3251"lb
.2220-15
¦35.9903
.2342-15
• 1 37B + 01
.1040-15
.1327-15
•37,3179
.6209-16
.1471 + 01
.9342-15
.6964-15
'34,9870
.6387-15
• 15B?+01
.3622-14
.6655-14
-38.5906
.1725-14
.1319+06
-------
Table D-6
SUMMARY OF TEST RESULTS ON ONE AIR SAMPLE (SEE TABLES D-4 AND D-5)
1
2
3
4
5
6
7
8
9
10
11
Data
Set
Code
Number
Cone, of
All Fibers,
106/m3
Size Dj
A]
Lstribution of
.1 Fibers
Volume Cone,
of all
Fibers,
10"15 cm3/m3
Number
Cone, of
Chrysotile,
106/m3
Size D:
CI
Lstribi
irysot]
xtion of
.le
Chrysotile
Mass Cone,
in Air,
Us/m3
Mean
Length,
Vim
Mean
Dia.,
Um
Mean
Volume,
10~15 cm3
Mean
Length,
Um
Mean
Dia.,
ym
Mean
Volume,
10"15 cm3
3-1
3-2
623.5
570.5
1.104
1.025
0.044
0.052
3.590
3.822
2238.4
2180.5
292.4
242.8
1.658
1.794
0.068
0.086
7.210
8.428
5.482
5.320
Mean
Std. Dev.
Std. Error (SEm)
t
t • SEm
95% Conf. Interval
Upper
Lower
597.0
37.48
26.50
12.706
336.71
933.71
260.29
2209.4
40.94
28.95
367.84
2577.24
1841.56
267.6
35.07
24.80
315.11
582.71
(negative)*
5.401
0.115
0.081
1.029
6.430
4.372
* Negative values are truncated to zero. Such situations are due to limited replication. It is recommended that
at least 3 or 4 TEM grids-be examined to substantially improve the precision, t-value decreases sharply to
4.30 for n = 3 and to 2.77 for n = 5. Also the standard error decreases with greater replication.
-------
TECHNICAL REPORT DATA
-------
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