EPA-670/2-75-050e
June 1975
Environmental Protection Technology Series
-------
EPA-670/2-75-050e
June 1975
DIRECT FILTRATION OF LAKE SUPERIOR
WATER FOR ASBESTIFORM FIBER REMOVAL
Appendix E
Ontario Research Foundation Electron Microscope Analysis Results
Appendix F
EPA National Water Quality Laboratory X-Ray Diffraction Analysis Results
Appendix G
University of Minnesota at Duluth Electron Microscope Analysis Results
By
Black $ Veatch, Consulting Engineers
Kansas City, Missouri 64114
Program Element No. 1CB047
Contract No. DACW 37-74-C-0079
Interagency Agreement EPA-IAG-D4-0388
USEPA, Region V and Corps of Engineers, St. Paul
Project Officer
Gary S. Logsdon
Water Supply Research Laboratory
National Environmental Research Center
Cincinnati, Ohio 45268
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
REVIEW NOTICE
The National Environmental Research Center -- Cincinnati
has reviewed this report and approved its publication. Approval
does not signifiy 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.
11
-------
FOREWORD
Man and his environment must be protected from the adverse
effects of pesticides, radiation, noise, and other forms of
pollution, and the unwise management of solid waste. Efforts
to protect the environment require a focus that recognizes the
interplay between the components of our physical environment --
air, water and land. The National Environmental Research Centers
provide this multidisciplinary focus through programs engaged in
• studies on the effects of environmental contaminants
on man and the biosphere, and
• a search for ways to prevent contamination and to
recycle valuable resources.
This report and its appendices present the results of pilot
plant filtration research for the removal of asbestiform fibers
from drinking water. The several appendices present detailed
information on water quality, pilot plant equipment and operation,
individual filter run data, asbestiform fiber and amphibole mass
concentrations in raw and filtered water, and diatomite filter
optimization. Appendix E contains electron microscope analytical
results from the Ontario Research Foundation. Appendix F contains
x-ray diffraction analytical results from the EPA National Water
Quality Laboratory in Duluth. Appendix G contains electron
microscope analysis results from the University of Minnesota at
Duluth.
A, W. Breidenbach, Ph.D.
Director
National Environmental
Research Center, Cincinnati
111
-------
ABSTRACT
Pilot plant research conducted in 1974 at Duluth, Minnesota,
demonstrated that asbestiform fiber counts in Lake Superior water
could be effectively reduced by municipal filtration plants.
During the study, engineering data were also obtained for making
cost estimates for construction and operation of both granular
and diatomaceous earth (DE) filtration plants ranging in size from
0.03 to 30 mgd.
Data provided to the contractor by the Ontario Research
Foundation are presented in Appendix E. ORF performed asbesti-
form, fiber analysis of water samples by the transmission electron
microscope method in this project. In order to place the data in
better perspective, a description of the analytical method used by
ORF is reproduced in Appendix E.
In Appendix F, the amphibole mass data obtained by the
National Water Quality Laboratory in Duluth are presented. This
appendix also includes information on the analytical methods used
at NWQL. The x-ray diffraction analysis for amphibole mass
provided confirmation of electron microscope amphibole fiber
results.
Fiber count data obtained at the University of Minnesota at
Duluth are tabulated in Appendix G. A statement describing the
electron microscope analytical method is also included.
IV
-------
CONTENTS
Appendix
Ontario Research Foundation Electron Microscope
Analysis Results of Pilot Water Treatment
Units - Raw Water from Duluth Lakewood Intake 1
Quantitative Analysis of Asbestos Minerals in
Air and Water (E. J. Chatfield) 9
Measuring Asbestos in the Environment (E. J.
Chatfield and H. Pullan) 11
EPA National Water Quality Laboratory X-Ray
Diffraction Analysis Results of Pilot Water
Treatment Units - Raw Water from Duluth
Lakewood Intake 16
Semi-quantitative Determination of Asbestiform
Amphibole Mineral Concentrations in Western
Lake Superior Water Samples (P. M. Cook) 24
Asbestiform Amphibole Minerals: Detection and
Measurement of High Concentrations in Muni-
cipal Water Supplies (P. M. Cook, G. E.
Glass, and J. H. Tucker) 35
University of Minnesota at Duluth Electron
Microscope Analysis Results of Pilot Water
Treatment Units - Raw Water from Duluth
Lakewood Intake 39
-------
APPENDIX E ONTARIO RESEARCH FOUNDATION ELECTRON MICROSCOPE ANALYSIS
RESULTS OF PILOT WATER TREATMENT UNITS - RAW WATER FROM
1 '
Date of
sample
4/19
4/25
5/7
5/9
5/16
5/16
5/16
5/16
5/16
5/30
5/30
5/30
5/30
5/30
6/4
6/4
6/4
6/4
6/4
6/6
6/6
Filter
utilized
MM-2
MM- 2
BIF
BIF
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
Run
No.
1
7
10-T
12-T
7
37
8
10
26
50
17
14
29
53
19
15
31
f/1
Raw
Sample0
A=0.304
C=0.217
A=0.348
C=0.174
A=0.522
C=0.130
A=0.870
C=1.78
A=2.61
C=1.35
A=1.43
C=1.83
A=1.74
C=2.91
A=1.52
C=2.35
x 106
Finished Per Cent
sample0 Removal
A=<0.0435
C=0.0435
A=<0.0435
C=0.348
A=<0.0435
C=1.43
A=<0.0435
C-<0.0435
A=<0.0435
C=0.130
A=<0.0435
C=0.174
A=0.565
C=0.652
A=0.261
C=1.04
A=<0.0435
C=0.261
A=<0.0435
C=0.913
A=0.739
C=1.83
A=<0.0435
CO.0435
A=<0..0435
C=0.478
A=<0.0435
C=1.87
A=0.217
C=0.0870
A=0.391
C=l . 00
A=<0.0435
C=0.348
85
80
87
—
98
90
98
87
90
23
97
86
96
50
97
98
97
83
97
36
77
66
97
85
-------
APPENDIX E (CONTINUED) .
Date of
sample
6/6
6/6
6/6
6/11
6/11
6/11
6/11
6/11
6/13
6/13
6/13
6/13
6/13
6/17
6/17
6/17
6/17
6/17
6/24
6/24
6/24
6/24
Filter
utilized
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-1
MM-l
MM-2
BIF
ERD-1
MM-1
MM-2
BIF
ERD-1
MM-1
MM-2
BIF
Run
No.
54
20
15
34
55
24
1A
36
57
28
1A
39
61
31
4A
44
71
37
f/1 x 106
Raw Finished Per Cent
sample0 sample0 Removal
A=0.0870
C=0.0870
A=0.0870
C=0.739
A=0.130
C=0.435
A=1.04
C=1.65
A=0.174
C=0.174
A=<0.087
C=2.26
A=0.174
C=0.261
A=0.957
C=9.31
A=0.48
C=0.41
A=<0.0217
C=0.57
A=0.15
C=2.02
A=0.80
C=0.46
A=0.09
C=0.71
A=0.61
C=2.15
A=<0.0217
C=0.44
A=0.04
C=0.37
A=0 . 09
C=0.39
A=<0.0217
C=1.37
A=1.04
C-3.91
A=.<0.0217
C=0.130
A=0.0217
C=0.978
A=<0.0217
C=0.239
40
65
91
82
83
89
91
—
8
—
96
—
69
—
97
79
93
83
97
36
80
97
98
75
-------
Date of
sample
6/24
6/28
6/28
6/28
6/28
6/28
7/3
7/3
7/3
7/3
7/3
7/19
7/19
7/19
7/19
7/19
7/23
7/23
7/23
7/23
7/23
Filter
utilized
ERD-2
MM-1
MM- 2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
M^l
MM-2
BIF
ERD-2
Run
No. .
22
48
76
47
28
52
78
51
32
67
96
70
40
70
99
72
41
f/1 x 106
Raw Finished Per Cent
sampled sampleP Removal
A=0.0217
C=0.239
A-l.ll A=0.91b
C=8.12 C=3.35b
A=< 0,0217
C=1.37
A=< 0.0217
C=0.52b
A=0.15
C=6.03
A=0.11
C=5.3
A=0.565
C=3.57
A=< 0.0217
C=0.283
A=0.0217
C=0.544
A=0.196
C=1.67
A=0.130
C=0.804
A=0.52
C=0.35
A=< 0.0217
C=0.15
A=0.02
C=0.04
A=<0.0435
C=<0.0435
A=0.11
C=0.22
A=0.54
C=0.09
A=<0.0217
C=0.07
A=<0.0217
C=0.20
A=.<0.0217
C=0.76
A=0.09
C=0.09
98
83
97
84
90
35
96
92
97
86
77
77
96
57
96
91
79
40
96
22
96
—
83
-------
APPENDIX E fCONTINURm.
Date of
sample
7/25
7/25
7/25
7/25
7/25
7/30
7/30
7/30
7/30
7/30
7/31
7/31
8/1
8/1
8/1
8/1
8/1
8/6
8/6
8/6
8/6
8/6
Filter
utilized
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
Run
No.
72
101
73
43
74
105
77
45
106
76
107
79
46
78
109
82
48
f/1 x 106
Raw Finished Per Cent
sample0 Sample0 Removal
A=0.11
C=1.43
A=<0.0217
C=0.37
A=<0.0217
C=0.15
A=0.04
C=0.35
A=<0.0217
C=0.44
A=0.11
C=0.11
A=<0.0217
C=<0.0217
A=<0.0217
C=0.04
A=<0.0217
C=0.07
A=<0.0217
C=0.07
A=0.33
C=0.22b
A=<0.0217
C=<0.0217
A=0.22
C=0.15
A=<0.0217
C=0.22
A=0.02
C=<0.0217
A=<0.0217
C=0.04
A=<0.0217
C=0.13
A=0.6
C=0.3
A=<0.0217
C=0.06
A=<0.0217
C=<0.0217
A=<0.0217
C=0.06
A=0.02
C=<0.0217
82
74
82
89
82
69
82
82
82
64
82
36
94
91
91
—
91
87
91
13
67
80
97
93
97
93
-------
APPENDIX E (CONTINUED).
Date of
sample
8/8
8/8
8/8
8/8
8/8
8/13
8/13
8/13
8/13
8/13
8/15
8/15
8/15
8/15
8/15
8/20
8/20
8/20
8/22
8/21
8/22
8/22
8/23
8/23
Filter
utilized
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
EKD-2
MM-2
EKD-2
MM-1
MM-1
MM-1
MM-2
Run
No.
80
111
84
49
82
113
88
51
84
114
89
55
118
59
86
86
86
119
f/1 x 106
Raw Finished Per Cent
sample sample Removal
A=0.06
C=0.09
A=0.04
C=0 . 20
A=<0.0217
C=0.09
A=<0.0217
C=0.4
A=<0.0217
C=0.04
A=0.13
C=0.20
A=<0.0217
C=0.03
A=<0.0217
C=1.4
A=<0.0217
C=0.1
A=0.04
C=0.50
A=0.09
C=0.17
A=<0.0217
C=0.52
A=0.02
C=0.22
A=0.15
C=0.44
A=0.04
C=0.04
A=0.30
C=0.72
A=0.02
C=2.1
A=<0.0217
0=0.17
A=0.13
C=0.37
A=<0.0217
C=0.13
A=<0.0217
C=0.22
A=<0.0217
C=0.80
A=0.72
C=0.44
A= 0.0217
C=0.28
33
—
67
—
67
55
85
85
85
—
69
—
78
—
78
—
55
76
93
—
93
76
85
65
85
40
85
—
97
36
-------
APPENDIX E (CONTINUED).
Date of
sample
8/23
8/28
8/28
8/28
8/30
8/30
8/30
8/30
9/4
9/4
9/4
9/4
9/6
9/6
9/6
9/6
9/9
9/9
9/9
9/10
9/10
9/11
9/11
Filter
utilized
ERD-2
MM-2
BIF
MM-2
BIF
ERD-2
MM-2
BIF
ERD-2
MM-2
BIF
ERD-2
BIF
ERD-2
MM-2
MM-2
Run
No.
63
122
103
124
105
68
126
108
70
128
111
72
113
73
131
133
f/1
Kaw
sample0
A=0.39
C=0.48
A=0.78
C=0.33
A=1.61
C=0.33
A=0.72
C=0.39
A=1.0
C=0.5
A=0.60
C=0.50
A=0.30
C=0.30
x 106
finished
sample0
A=0.02
C=0.59
A=<0.0217
C=0.04
A=0.15
C=0.24
A=0.02
C=0.30
A=0.04
C=0.17
A=<0.0217
C=0.54
A=<0.0217
C=<0.0217
A=0.17
01.15
A=<0.0217
C=0.54
A=<0.0217
C=0.37
A=0.02
C=0.59
A=<0.0217
C=1.67
A=0.04
C=1.0
A=< 0.0217
C=1.0
A=< 0.0217
C=0.5
A=0.02
C-0 . 30
Per Cent
Removal
97
__
95
92
97
— _
97
__
99
94
99
97
50
97
__
98
—
97
—
93
-------
APPENDIX E (CONTINUED).
Date of
sample
9/11
9/13
9/13
9/13
9/13
9/16
9/16
9/16
9/16
9/17
9/17
9/19
9/19
9/19
9/19
9/20
9/20
Filter
utilized
BIF
MM-2
BIF
ERD-2
MM-2
BIF
ERD-2
MM-2
MM-1
MM-2
BIF
ERD-2
Run
No.
115
137
117
78
138
118
79
139
87
140
120
85
f/1 x 106
Raw Finished Per Cent
sample0 sample0 Removal
A=< 0.0217
C=0.10
A=0.02
C=0.06
A=0.02
C=0.10
A=0.02
C=0.40
A=< 0.0217
C=0.06
A=0.90
C=0.10
A=0.02
C=0.30
A=<0.0217
C=1.30
A=0.02
C=0.06
A=0.20
C=0.10
A-<0.0217
C=0.10
A=0.60
C=0.09
A=1.00
C=0.70
A=< 0.0217
C=0.30
A=0.02
C=1.80
A=1.3
C=0.2
A=0.02
C=0.32
93
67
—
__
98
__
98
40
90
__
—
__
97
—
98
~*~
BDL - Below detectable limits of analysis equipment
Cloquet Pipeline water
A = amphibole, C = chrysotile
-------
10
00
<0 8
O
cr
UJ
UJ
m
OL
O
— 3
I-
co
UJ
00 «
AMPHIBOLE
-^ CHYRSOTILE
5 15 25
APRIL
15 25
MAY
15
JUNE
25
15 25 5 15 25
JULY AUGUST
5 15 25
SEPTEMBER
FIGURE I. ONTARIO RESEARCH FOUNDATION
ASBESTIFORM FIBER COUNTS
RAW WATER AT DULUTH LAKEWOOD INTAKE- 1974
-------
QUANTITATIVE ANALYSIS OF ASBESTOS MINERALS IN AIR AND WATER
E. J. Chatfield
Dept. of Applied Physics, Ontario Research Foundation, Sheridan Park,
Mississauga, Ontario, Canada
The effects of inhalation o.f asbestos particles are well known. (*) However,
although the significance of asbestos particles when ingested is not fully
understood, there is some evidence of increased incidence 6f gastrointestinal
carcinoma where individuals have been exposed to the material over a long
period. (s) Methods are therefore required by which trace concentrations of
asbestos minerals in both air and ingestibles can be monitored.
Asbestifonn minerals fall into two groups, serpentine and amphibole. Chryso-
tile is the only asbestifonn member of the serpentine type, consisting of
magnesium silicate Mg3Si205(OH). The asbestifonn amphiboles have a range of
composition X7Si8022(OK)2 where X may be Na, Fe2*, Fea+, Mg or Ca in various
combinations. The principal types of amphibole commonly encountered include
crocidolite, anthophyllite, tremolite, and amosite, although amosite itself
has a number of sub-species of variable compositions. Although it is common-
ly thought that asbestos minerals are indestructible, in practice they are
decomposed by heat or acids to a variable degree depending on the particular
variety. This property restricts the treatment possible in any analytical
procedure. This paper describes an analytical technique which is suitable
for detection and measurement of low concentrations of asbestifonn minerals
in air and water samples.
The first step in the procedure is to collect some of the solid material on a
O.lpjn pore size membrane filter. In the case of air, about 5m3 is filtered;
about 200ml in the case of a measurement on water. The membrane filter is
then ashed in a clean glass vial using a plasma microincineration technique.
The ashing takes place at low temperatures (typically 70°C), thus whilst no
decomposition of the mineral fibers can occur, organic materials and the
filter itself are oxidised to C02. The residue is gently redispersed ultra-
sonically in filtered distilled water, and the suspension centrifuged on to a
1cm diameter glass cover disc. The disc is dried and a thin carbon coating
is applied by evaporation. The carbon film is scored and floated off on to
water, carrying the particles with it; pieces of this are then picked up on
200 mesh copper grids. A maximum of 10 grid squares is searched for asbestos
particles at a magnification of about 25000. Particles are identified at the
instrument by electron diffraction, and measured in both length and width by
comparison with a series of geometrically spaced calibration circles scored
on the fluorescent screen of the microscope. Typical crocidolite particles
are shown in Figure 1, and their single fiber diffraction pattern is shown in
Figure 2. Figures 3 and U show typical amosite particles and their single
fiber diffraction pattern. It can be seen that the diffraction patterns in
this case are quite different, although identification within the amphibole
series is not generally so simple. In contrast, chrysotile can be easily
distinguished by both morphology and its diffraction pattern.
The particle counts are processed by a computer program, which calculates the
particle number and mass concentrations; it also plots the number and mass
sice distributions. Using the sample volumes specified, air concentrations
can be measured down to about 0.01 fibers/cc, and water concentrations to 10*
fibers/liter in typical cases. The actual sensitivity depends on the degree
of concentration which can be achieved, whilst retaining a suitable micro-
scope specimen. This in turn is determined by the concentration of extra-
neous material present in the original sample.
Quantitative Analysis of Asbestos Minerals in Air and Water by E. J.
Chatfield is reprinted from 32nd Ann. Proc. Electron Microscopy Soc.
Amer., St. Louis, Missouri, 1974, C. J. Arceneaux (ed.), with permis-
sion of Claitors Publishing Division, 3165 South Arcadin, Baton
Rouge, La.
-------
Reprinted from:
32nd Ann. Proc. Electron Microscopy Soc. Amer."
St. Louis, Missouri, 1974. C. J. Arceneaux (ed.).
An extensive study has been made of water samples in Ontario,(3) following a
small pilot study by a different technique.(4) The water in Ontario general-
ly contains an average of about 2 million fibers of chrysotile per liter, and
usually no detectable amphibole types.
1. I. J. Selikoff et al, Arch. Environ. Health, 25, p. 1-13, (1972).
2. . T. F. Mancuso and E. J. Coulter, Arch. Environ. Health, 6, p. 210, (1963).
3. G. Kay, Water and Pollution Control, Sept. 1973, p. 33-35.
4. J. M. Cunningham and R. Pontefract, Nature, 232, p. 332, (1971).
Figure 1. Crocidolite Fibers
Figure 2. Crocidolite Single Fiber
Diffraction Pattern
Figure 3. Amosite Fibers
Figure 4. Amosite Single Fiber
Diffraction Pattern
10
-------
Measuring Asbestos in the Environment by E. J. Chatfield and H. Pullan is reprinted
from Canadian Research & Development, Nov-Dec, 1974, with permission of Maclean-
Hunter Ltd., 481 Univ. Ave., Toronto, Ontario M5W-1A7. (Pages 23-27.)
Measuring asbestos in the environment
THE INCIDENCE of asbestos-related
disease reported by medical author-
ities and its classification as a hazard-
ous material " "' has created a need
for techniques by which it can be
measured at low concentrations in
air and water samples.
To appreciate the criteria involved
in the design of such low level ana-
lytical methods, it is useful to review
some of the recent history of as-
bestos-related disease, the estab-
lished maximum occupational expo-
sure levels, and the properties of the
materials themselves. Until recently,
inhalation was considered to be the
only hazard associated with this ma-
terial, and fairly reliable data are
available relating the incidence of
the progressive disease asbestosis
with the individual's exposure. In-
deed, occupational exposure levels
have been defined for some years in
both the USA and Britain. However,
in the last few years a previously rare
malignancy condition, mesothe-
lioma, has been linked with exposure
to asbestos, this exposure not always
being an occupational one. " Fur-
thermore, statistical studies have
shown that persons exposed to
asbestos minerals show a greater in-
cidence of various types of gastroin-
testinal carcinoma. -' • '• As a con-
sequence, public health authorities
in most civilized countries are re-as-
sessing the significance of the pres-
ence of asbestos minerals in the envi-
ronment. The discovery that many
Canadian water supplies contain up-
wards of 1 million asbestos fibres per
litre '- " has also given cause for sur-
veys of municipal water sources to
be made, whilst in the United States,
disposal of mine tailings in Lake Su-
perior in the vicinity of Duluth, Min-
nesota has led to an extended Fed-
eral court action 1J against the
company involved. These recent
events indicate the seriousness with
which the authorities now view the
natural presence of, or the discharge
of, this material into the environ-
ment, and it appears to be only a
matter of time before some guide-
lines are established concerning ac-
ceptable levels in both air and water
by E. J. Chatfield and H. Pullan
Department of Applied Physics
Ontario Research Foundation
Sheridan Park, Ontario
for the general population. '"• On the
other hand, the importance of as-
bestos in most sectors of the econ-
omy cannot be denied
As previously mentioned, occu-
pational levels for workers in the as-
bestos industry have existed for some
time, however, there appears to be a
considerable divergence of opinion
on just how these levels should be es-
tablished. The recommended North
American occupational MFC (Max-
imum Permissible Concentration)
for air has been set at 5 fibres/ml; '"
a further condition is that only those
fibres greater than 5 jum in length are
included in this figure. At the time of
writing there is no MFC for inges-
tibles. The occupational MFC in the
UK has been set at 2 fibres/ml, '"i:
with the same fibre length limitation.
In this case, some discrimination be-
tween the various asbestos mineral
types is exercised, and mass concen-
tration values are also equated to
these for convenience of measure-
ment. It must be emphasized that
these are all OCCUPATIONAL lev-
els which are established using sta-
tistical data and by defining some
small incidence of asbestos-related
disease in the industry as acceptable.
If the normal philosophy used in
radiation protection were to be ap-
plied, acceptable levels for exposure
of the general population would log-
ically be set at substantially lower
values, perhaps one order of magni-
tude or so lower. The design of a
suitable measurement technique for
asbestos minerals must therefore
take account of the low levels to be
measured For air, a suitable lower
detection limit appears to be about
0.01 fibres/ml, whilst for water the
corresponding value would be about
1O fibres/litre, this latter figure be-
ing about 100 times less than the av-
erage concentrations normally
found.
Asbestos is a generic term used for
two families of minerals which have
a fibruous texture and which can be
split into individual, sometimes very
flexible fibres. The first group are the
serpentines, of which chrysotile is
the only fibrous member. This min-
eral comprises most of the world's
production, and nearly all of the Ca-
nadian contribution to it It is a hy-
drated magnesium silicate, having
the composition Mg.Si.O, (OH),,
and is not the "indestructible" mate-
rial it is commonly thought to be It
is attacked by even the weak acids,
such as acetic acid, and decomposes
on heating at 450C to Forstente,
which is not fibrous, although it may
still retain the fibrous morphology of
the parent material Individual fibres
of chrysotile have been observed to
decompose at temperatures as low as
250C'" The other group of fibrous
minerals are the amphiboles, which
have the general composition
X;Si_O,,(OH), where X may be Na#,
Fejd, Fe'd, MgJ#, or CaJ$ in various
combinations.1" These minerals pos-
sess greater resistance to acids and
heat than chrysotile, and a number
of specific compositions are recog-
nized and named as individual min-
erals. The principal types thus recog-
nized are amosite, grunente,
anthophylhte, crocidolite, actinohte
and tremolite. The amosite-grunente
series has a variable composition
which has led to the naming of a
number of other sub-species such as
Cummingtonite, the mineral in-
volved in the western arm of Lake
Superior.
From the compositions given
above, it can be seen that many other
mineral species may have similar
compositions, yet not be asbestiform
types. The only identification tech-
nique open to us, therefore, is one
sensitive to the crystal structure, i.e
either electron or X-ray diffraction
Chemical analysis by itself is not
useful. In some cases, only a combi-
nation of the two is adequate Since
most of the health criteria are stated
in terms of fibre number concentra-
tions, all mass measurement tech-
niques, including X-ray diffraction,
are excluded. In any case, X-ray dif-
fraction is of marginal sensitivity,
particularly when other common
minerals such as kaolmite are also
present.-"1 Along with most other m-
11
-------
Figure 6-Elcctron diffraction pattern of amos/fe
Figure 5—Election micrograph of amoiite Arf.CCC1
Figure 4—Electron ijiltraction pattern^of crocidolite
Figure 3—Electron micrograph ot ciucicjolne AJJ
Figure 2—Electron diffraction pattern ot chrysolite asbestos
Figuie 1 —Electron micrograph of chrysotili'- asbestos,
X84.000
12
-------
vestigators. we elected for the only
obvious approach, particle counting
by electron microscopy, combined
with electron diffraction for identi-
fication.1J -'--'' Although scanning
electron microscopy has also been
suggested as a suitable alternative, it
is evident that identification can only
be based on morphology, with per-
haps some chemical data from
energy dispersive X-ray analysis.
Optical microscopy, using tech-
niques such as that currently used for
health control in the industry, is also
inapplicable to trace measurement in
environmental samples, since this
technique assumes all fibrous mate-
rial to be asbestos and lacks any easy
identification technique for small
particles. It is also found that many
fibres have widths much lower than
those capable of being resolved by
the optical microscope, even though
their lengths may exceed the 5 /xm
length limit sometimes specified.
The whole topic of trace asbestos
measurement is surrounded by con-
troversy, and the area subject to most
dispute is undoubtedly that of speci-
men preparation. The requirement
of the preparation technique is to
quantitatively deposit the solid con-^
tent of an air or water sample onto
an electron microscope specimen
support film. It would be desirable to
use the technique of Kalmus,J? in
which direct dissolution of the mem-
brane filter is achieved by reflux
washing in acetone vapour, thus de-
positing the paniculate material
quantitatively on a carbon coated
electron microscope grid. This tech-
nique suffers from the disadvantage
that some smaller particles are
washed away; a fact that can easily
be checked by processing a radio-
active particulate sample. More sig-
nificantly, raw water samples often
contain an overwhelming proportion
of organic material, which necessi-
tates dilution of the sample so that a
reasonably loaded electron micro-
scope sample can be obtained. This
dilution has the undesirable effect -of
separating the asbestos fibres more
widely, thus requiring more counting
time. Also the large amount of extra-
neous organic material obscures
many of the fibres. It is therefore
preferable to contrate the asbestos
fibres at the expense of the organic
materials present.
The technique developed for anal-
ysis of water samples at ORF is a
modification of those described by
Cunningham and Pontefract,1-' and
Biles and Emerson.-'' At this time it
represents the only published tech-
nique which has been tested for mass
balance using standard asbestos dis-
persions. Even this has only been
tested in the case of chrysotile The
same method is also used for air
samples collected on membrane fil-
ters.
The first step in the procedure is to
collect some of the solid material on
a filler. In the case of air, the collec-
tion properties of membrane filters
allow pore sizes of 0.4 jum or even 0.8
,um to be used, and a volume "of
about 5m is filtered. For water sam-
ples, the particle sizes collected are
strictly a function of pore size, and
the smallest pore size compatible
with a reasonable flow-rate is se-
lected. In practice 0.1 fus the smallest
convenient pore size, and a volume
of about 200ml of the water is fil-
tered. The remaining steps in the
alaytical procedure for both types of
sample are identical. The filter is
transferred to a clean glass vial,
which is then placed in a plasma mi-
cro-incinerator (low temperature
asher). In this device the filter is oxi-
dized, along with all other organic
materials present, with very little dis-
turbance at a temperature of less
than 80CV- The oxidation takes
place in oxygen at a pressure of
about 1 Torr, which is excited by a
radio-frequency discharge. After
some hours the vial containing the
residue is removed and double dis-
tilled water added. The ashed resi-
dues are gently dispersed ultrason-
ically and an aliquot of the
dispersion is centnfuged on to a 1cm
diameter cover glass at an acceler-
ation of 8,000g for about 20 minutes
In practice, a drop of very dilute de-
tergent is also added to the centri-
fuge tube for a reason which is re-
ferred to later. The disc is removed,
dried and a thin carbon coating ap-
plied by vacuum evaporation. The
carbon film is scored by a scalpel
blade, and is then floated on to wa-
ter, carrying the deposit of particles
with it. The detergent which was
added to the centrifuge tube assists
in the removal of the carbon film
from the glass disc. Pieces of the car-
bon are then picked up on 200 mesh
electron microscope support grids.
About 10 grid squares, selected
from several grids, are searched for
asbestos particles using a trans-
ASBESTOS FIBRE COUNT ANALYSIS
SIZE PARTICLE NUMBER CUM CUM NO
CATEGORY SIZE, UM COUNTED NUMBER PERCENT
I
2
3
A
5
6
7
8
9
10
11
12
13
14
15
16
17
0.040
0.057
0.080
0. 1 13
0.J60
0.226
0.320
0.453
0.640
0.905
1.280
810
I
2.560
3.620
5.1 20
7.241
10.240
0
0
1
20
16
16
16
8
7
2
I
1
0
0
1
•0
0.0
0.0
0.0
0.5
11.0
29.0
45.0
61.0
73.0
80.5
85.0
86.5
87.5
88.0
88.0
88.5
89.0
0.00
0.00
0.00
0.56
12.36
32.58
50.56
68.54
82.02
90.45
95.51
97.19
98.31
98.88
98.88
99.44
100.00
DATE: 15/12/73
CUM MASS
PERCENT
0.00
0.00
0.00
0.09
2.86
8.94
16.88
27.47
38.87
49.50
58.00
64.23
71.53
75.81
75.81
87.90
100.00
TOTAL NUMBER OF PARTICLES COUNTED = 89
SIZE OF GRID SQUARE USED = 85 MICROMETRES
NUMBER OF GRID SQUARES COUNTED = 10
DENSITY USED IN MASS CALCULATION : 2.40 G/CC
TYPE OF ASBESTIFORM COUNTED - CHRYSOTILE
6
CONCENTRATION OF ASBESTOS = 1.93 X 10 FIBRES/LITRE
-3
ESTIMATED MASS CONCENTRATION : 3.93 X 10 MICROGRAMS/LITRE
It
I.E. ONE PART OF ASBESTOS IN 2.55 X 10 PARTS OF LIQUID
LOWEST DETECTABLE LEVELS UNDER THE
CONDITIONS USED IN THESE MEASUREMENTS
4
NUMBER - 2.17 X 10 FIBRES/LITRE
-6
MASS - 7.42 X 10 MICROGRAMS/LITRE
Figure 7—Computer printout for a chrysotile-in-water sample
13
-------
ASBESTOS FIBRE LENGTH DISTRIBUTION
DATE: IV12/7J
FIBRt LtNGTH,
MICROMETRES
10+
8+
6+
4+
2+
1 +
0.8+
0.6+
0.4+
0.2+
0.1 +
.08+
TYPE OF ASBESTIFORM
NUMBER OF FIBRES SIZED
CHRYSOTILE
89
.06+
0.5 1
10 20 50 40 50 60 70 80 90 95 98 99 .5
CUMULATIVE PERCENTAGE NUMBER
LESS THAN STATED LENGTH (LOT,. PROBABILITY SCALE)
Figure 8—Fibre length distribution of a typical sample
Figure 9—Removing a set of samples from the asher
mission electron microscope at a
magnification of approximately
25,000. Asbestiform particles are
identified individual!} by electron
diffraction, and their lengths and
widths are measured
The particle counting is normally
terminated after 10 grid squares have
been examined, or when about 100
particles have been counted Both
the detection level and the accuracy
can be improved by additional
counting, but for economic reasons
these arbitrary limits have usually
been applied The minimum level,
i.e. one particle detected, corre-
sponds to about 10' particles/litre
for water samples, or 001 particles/
ml for air samples, whilst detection
of about 100 particles yields an accu-
racy of \0r/f
The data are then processed by a
computer program, which calculates
both number and mass concentra-
tions, and also plots the size distribu-
tions.
It is the practice of some workers
to identify only a minor proportion
of the asbestos particles by diffrac-
tion Although chrysotile may be
identified primarily by its character-
istic morphology in the transmission
electron image, the amphiboles pos-
sess no such characteristic appear-
ance In water samples, particularly,
diatomaceous and mica fragments
can often be mistaken for amphibolc
fibres It proves little to identify only
}5''i of the reported fibres by diffrac-
tion, and the ORh alaytical team re-
port only those amphibole fibres
which have been so confirmed.
1 he technique has been criticized
for Us use of ultrasonics to redisperse
the sample residues after the ashing
procedure The concern is that the
ultrasonic treatment may break up
the fibres, giving rise to an artificially
high measurement In fact if can he-
shown that power densities of some
watts/ml are required before signifi-
cant breakage of suspended particles
occurs, whereas the power densities
used in Ihis technique are only a few
milliwatts/ml However, although
we do not regard this as a cause lor
concern, there are many unresolved
questions K>r example, water sam-
ples have to be collected in the field.
and these are usually stored in bot-
tles during transit to the laboratory
Nothing is known about the scav-
enging action of the bottle's interior
surfaces on the suspended particles
during storage, the effect of pH, or
whether plastic or glass bottles
should be used on this account. This
effect may also be dependent on par-
ticle concentration The only reliable
procedure may be that of immediate
14
-------
filtration. The mass balance in many
of the analytical methods in use is
also suspect, and may indicate that
results being obtained are lower than
the real values.
Contamination is a very serious
problem: almost all reagents, glass-
ware, water, etc., are contaminated
in some degree with chrysotile as-
bestos, and the most extreme pre-
cautions must be taken to eliminate
this. Even some membrane filters
have been found to contain amounts
of chrysotile which can disrupt the
measurement At ORF we perform
critical phases of sample preparation
in a positive pressure clean room,
from which all known sources of as-
bestos have been excluded The air
supply is filtered and passed through
an electrostatic precipitator. The
floor is of pure vinyl, rather than vi-
nyl-asbestos, and a suspended ceiling
was fitted to prevent possible fallout
from insulated air ducts and pipes.
To minimize the dust problem, steel
furniture was installed rather than
the wood variety. Any visible dust is
treated with suspicion and cleaned
up using wet tissues to prevent its
dispersal. Disposable laboratory
coats and overshoes are used by all
personnel entering this area Glass-
ware is cleaned before use in chro-
mic acid, and then rinsed in double
distilled water. Only by observing
the strictest hygiene, comparable
with that necessary during handling
of radioactive isotopes, is it possible
to maintain the low background
measurements which we routinely
achieve Even use of some types of
talcum powder or cosmetics by the
individuals performing sample prep-
aration can cause a perplexing series
of contaminated samples to arise
where blank measurements were ex-
pected.
The techniques in use at ORF for
trace asbestos measurement have
been developed over a period of
three years. During that time many
of the difficulties have been identi-
fied and solutions found However,
there is a pressing need for further
development work, particularly in
the field of quantitative sample prep-
aration A development program is
therefore being initiated at ORF to
investigate the various aspects of
sample preparation and storage, with
the eventual aim of defining a rec-
ommended analytical procedure
which has been thoroughly tested.
Until this program is completed, the
current method, which gives reason-
ably reliable data at an economically
acceptable cost, will remain in use
References
1 Selikofl I J et al Arch Environ Health V ol 25
1972 page 1
2 Mancuso 1 F and Coulter F J Arch Environ
Health Vol 6 1963 page 210
3 Howihane D O Ann NY Acad Sci 132 165
page 647
4 Wagner J C' Ann NY Acid Sci 132 1965, page
575
5 Knox j I et al Bnl J Indus! Mcd 25 1968
page 293
6 Newhouse M L and V. agner J C Brit J Indus!
Med 26. 1969 page 302
7 Real F f Fancet n 1960 page 1211
8 Hmson K F V. Bit I Dis Chest 59 |965 page
121
9 Federal Register {L S A 1 Vol 32 No 110 1972
page 11318
10 Statutory Instruments (L K ) 1969 No 691) Facto-
ries I he Asbestos Regulations
1) Nevcbouse M 1 and I hompson H Bnl I ln-
dustr Med 22 1965. page 261
12 C unnmgham H M and I'ontetract, R Nature
232 1971 page 332
13 Kav (j H lournal A W V> A Sept 1974 page
513 and Watei and Pollution Control Sept 1973
15 Bnckman L and Rubmo RA "National Behind a
Proposed Asbestos A;r Qualitv Standard" 67th
Meeting ol Air Pollution C onlrol Association Den-
ver Col 1974
16 Aver II 1 et al Ann N\ Acad Sciences 132 Arl
I 1965 page 274
17 Brit Oec Health Soc Report ot ( ommiltee on Hv -
giene Standards Hvgiene Standards lor C hr\sotile
Asbestos Dust fXc 1967
18 Berrv F Private C ommumcation
19 Industrial Minerals and Rods Fd .1 I (nlson
AIM! page 48 (1968|
JO Rickards A I and Badami D \ Nature 234
1971 page 93
Jl Smith Cr R et al Proceedings Fleetron Micro-
scopv Societv ol America 1973 page 310
22 \\alkcr C V, ct al Proceedings Fleetron Micro-
scopv Socielv ol \merica 1974 page s24
23 Mudroch <) and Kramer I R Ibid page 526
24 C hatlielcl E J Ibid page 52k
js ( hatlicld I I Proceedings Microscopical Societv
ol Canada 1974 page 24
26 Biles B and i merson I R Nature 219 1968
page 93
27 Kalmus 1 H I Appl Plus 2s (19^41
2K Thomas. R S and C orletl M I Proceedings Flee-
tron Microscopv Noeietv ol America 1973 page
334 fj
Figure 10—Identifying an asbestos fibre in the transmission electron microscope
-------
APPENDIX F EPA NATIONAL WATER QUALITY LABORATORY X-RAY DIFFRACTION ANALYSIS
RESULTS OF PILOT WATER TREATMENT UNITS - RAW WATER FROM DULUTH
LAKEWOOD INTAKE.
Date of
sample
4/19
4/25
5/7
5/9
5/16
5/16
5/16
5/16
5/16
5/22
5/22
5/22
5/22
5/22
5/30
5/30
5/30
5/30
5/30
6/4
6/4
6/4
6/4
6/4
6/6
6/6
6/6
6/6
6/6
6/11
6/11
6/11
6/11
6/11
6/17
6/17
6/17
6/17
6/17
6/28
6/28
Filter
utilized
MM- 2
MM-2
BIF
BIF
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-1
MM-1
MM-2
BIF
ERD-1
Run
No.
1
7
10-T
12-T
7
37
8
10
16
43
11
13
26
50
17
14
29
53
19
15
31
54
20
15
34
55
24
1A
39
61
31
4A
Amphibole mass
SS (mg/1) concentration (mg/1) Per Cent
Raw Finished
0.90 0.43
0.86 0.39
0.69 0.09
0.61 0.31
0.64
0.13
0.05
0.12
0.05
0.74
0.33
0.13
2.63a
0.04
0.68
0.10
0.05
1.02a
0.10
0.57
0.09
0.02
0.11
0.10
0.77
0.12
0.04
0.17
0.36a
1.30
0.24
0.07
0.59a
1.47
0.86
0.12
0.08
3.22a
0.06
0.74
2.09b
Raw Finished
0.10 <0.02
0.12 <0.02
0.06 <0.01
0.22 0.003
0.14
0.005
0.003
0.006
0.003
0.20
<0.01
<0.003
<0.03
0.002
0.19
<0.01
0.005
<0.02
0.004
0.26
<0.006
<0.006
0.004
0.003
0.18
<0.005
<0.005
0.004
<0.004
0.18
0.006
<0.004
0.008
<0.02
0.17
<0.006
<0.01
<0.03
<0.005
0.16.
f\
0.11°
Removal
80
83
83
98
96
98
96
98
95
98
99
95
97
98
98
98
99
97
97
98
97
98
89
96
94
97
16
-------
APPENDIX F (CONTINUED)
Date of
sample
6/28
6/28
6/28
6/28
7/3
7/3
7/3
7/3
7/3
7/19
7/19
7/19
7/19
7/19
7/23
7/23
7/23
7/23
7/23
7/25
7/25
7/25
7/25
7/25
7/30
7/30
7/30
7/30
7/30
7/30
7/30
7/31
7/31
8/1
8/1
8/1
8/1
8/1
8/6
8/6
8/6
8/6
8/6
8/8
8/8
8/8
Filter
utilized
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-2
MM-1
MM-2
BIF
ERD-2
MM-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
Run
No.
48
76
47
28
52
78
51
32
67
96
70
40
70
99
72
41
72
101
73
43
104
74
105
77
45
106
76
107
79
46
78
109
82
48
80
111
Amphibole mass
SS (mg/1) concentration (mg/l)Per Cent
Raw Finished
0.76
0.04b
0.38
0.68
0.75
0.11
0.08
0.65a
0.12
0.88
0.10
0.18
0.60a
0.04
0.59
0.03
0.08
0.70a
0.06
0.68
0.08
0.10
0.45a
0.03
0.68
0.78°
0.64
0.03
0.14
0.13
0.04
2. 58 b
0.09b
0.90
0.06
0.06
0.24a
0.06
0.70
0.03
0.06
0.71a
0.03
0.64
0.06
0.10
Raw Finished
0.007
<0.005b
<0.008
<0.01
0.07
<0.004
<0.003
<0.004
0.003
0.13
<0.003
<0.005
<0.003
<0.003
0.09
<0.003
<0.004
0.007
<0.003
0.04
<0.005
<0.005
<0.004
<0.003
0.10
0.02
0.06
<0.003
<0.005
<0.003
<0.003
0.10b
<0.003b
0.08
<0.004
<0.003
0.01
<0.002
0.09
<0.003
<0.003
<0.007
<0.002
0.05
<0.003
<0.003
Removal
97
95
91
95
96
96
98
96
98
97
95
97
87
87
92
80
95
92
95
97
95
96
97
97
97
98
94
94
17
-------
APPENDIX F (CONTINUED),
Date of
sample
8/8
8/8
8/13
8/13
8/13
8/13
8/13
8/15
8/15
8/15
8/15
8/15
8/20
8/20
8/20
8/21
8/22
8/22
8/22
8/23
8/23
8/23
8/28
8/28
8/28
8/30
8/30
8/30
8/30
9/4
9/4
9/4
9/4
9/6
9/6
9/6
9/6
9/9
9/9
9/9
9/10
9/10
Filter
utilized
BIF
ERD-2
MM-1
MM- 2
BIF
ERD-2
MM-1
MM- 2
BIF
ERD-2
MM- 2
ERD-2
MM-1
MM-1
MM-1
MM- 2
ERD-2
MM-2
BIF
MM-2
BIF
ERD-2
MM-2
BIF
ERD-2
MM-2
BIF
ERD-2
BIF
ERD-2
MM-2
Run
No.
84
49
82
113
88
51
84
114
89
55
118
59
86
86
86
119
63
122
103
124
105
68
126
108
70
128
111
72
113
73
131
Amphibole mass
SS (mg/1) concentration (mg/l)Per Cent
Raw Finished
0.59a
0.04
0.67
0.03
0.04
0.47a
0.09
0.81
0.08
0.05
0.25
0.16
0.81
0.09
0.04
0.05
0.70
0.06
0.06
0.63
0.02
0.05
0.54
0.02
0.14
0.41
0.03
0.27a
0.008
0.72
0.03
0.55a
0.03
0.61
0.04
0.38a
0.01
0.60
0.10
0.03
0.62
0.08
Raw Finished
<0.006
<0.002
0.06
<0.003
<0.003
<0.005
<0.003
0.06
<0.003
<0.003
<0.003
<0.003
0.02
<0.003
<0.003
<0.003
0.03
<0.003
<0.003
0.04
<0.003
<0.003
0.09
<0.003
<0.003
0.07
<0.003
<0.003
<0.003
0.10
<0.003
<0.006
<0.003
0.07
<0.003
<0.003
<0.003
0.04
<0.003
<0.003
0.05
<0.003
Removal
96
95
95
95
95
95
95
85
85
85
90
90
92
92
97
96
97
97
97
96
96
92
94
18
-------
APPENDIX F (CONTINUED)
Date of
sample
9/11
9/11
9/11
9/13
9/13
9/13
9/13
9/16
9/16
9/16
9/16
9/17
9/17
9/19
9/19
9/19
9/19
9/20
9/20
Filter
utilized
MM-2
BIF
MM-2
BIF
ERD-2
MM-2
BIF
ERD-2
MM-2
MM-1
MM-2
BIF
ERD-2
Run
No.
133
115
137
117
78
138
118
79
139
87
140
120
85
SS (mg/1)
Raw Finished
0.63
0.08
0.52a
0.51
0.03
0.25
0.02
0.31
0.04
0.39a
0.04
0.58
0.07
0.50
0.06
0.03
0.40a
0.40
0.003
Amphibble mass
concentration (mg/l)Per Cent
Raw
0.06
0.09
0.08
0.06
0.10
0.07
Finished
<0.003
<0.005
<0.003
<0.003
<0.003
<0.003
<0.004
<0.003
<0.003
<0.003
0.003
<0.004
<0.003
Removal
95
97
97
96
96
95
97
97
96
a Mostly DE
b Cloquet Pipeline water
c Mostly alum and DE, sample purposely collected after turbidity break-
through
19
-------
At the concentrations of fibers encountered in Lake Superior water, there
appeared to be no correlation between turbidity and fiber counts for either
amphibole or chrysotile fibers. However, there was a relationship between
raw water amphibole mass and amphibole fiber counts, as shown in Figure 1.
Using linear regression analysis, the following was obtained:
F/l = (0.15 + 6.2 Mass) x 106
F/l = amphibole fiber count, 10 f/1
Mass = amphibole mass, mg/1
The correlation coefficient, r, was 0.48.
4.0
cr.
o
O £
00 —
>• h-
I- <
3.0
LJ
o
2.0
a:
UJ
o
z x
o a-
1.0
1.0 2.0 3.0
AMPHIBOLE FIBERS /LITER X |Q6
ONTARIO RESEARCH FOUNDATION
4.0
FIGURE |. CORRELATION BETWEEN NWQL AMPHIBOLE MASS CONCENTRATION
AND ORF AMPHIBOLE FIBER COUNTS-RAW WATER AT DULUTH
LAKEWOOD INTAKE -1974.
20
-------
o
(- 0.9
0-8
O
o
0.7
O
m 0.6
^ Q.
0.5
O" Q
e z
**• 0.4
CO
Q
O 0.3
CO
Q
z
UJ
Q.
CO
0.2
o.i
.O SUSPENDED SOLIDS
• AMPHIBOLE
5 15 25
APRIL
15
MAY
25
5 IS 25
JUNE
IS 25
JULY
5 IS 25
AUGUST
5 15 25
SEPTEMBER
FIGURE 2. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL WATER QUALITY LABORATORY
SUSPENDED SOLIDS AND AMPHIBOLE MASS CONCENTRATION
RAW WATER AT DULUTH LAKEWOOD INTAKE - 1974
-------
ADVANCES IN
X-RAY ANALYSIS
Volume 18
Edited by
William L. Pickles
Lawrence Livermore Ijiboratory
Liverniore, California
and
Charles S. Barrett, John B. Newkirk, and Clayton O. Ruud
Denver Research Institute
The University of Denver
Denver, Colorado
Sponsored by
University of Denver
Denver Research Institute
Metallurgy and Materials Science Division
PLENUM PRESS • NEW YORK AND LONDON
22
-------
The Library of Congress cataloged the first volume of this title as follows:
Conference on Application of X-ray Analysis.
Proceedings. 6>.h- 1957-
iDenveri
T. tllus. 24-28 cm annual
No proceedings published for the tint ~t i-onferenoes.
Vols. for VJfift- called al*'> Advances in X-tuy analyst*, T 2-
Proceedlne* for 19~»7 f"'jed by rip Ci.nferercs un^fr an et\-.ier
name: Conference on Industrial Applications of X-ray Analyst*.
Other slight rnri.itlons In name o? conference
Vol. for 19T>7 ptjbl'
-------
SEMI-QUANTITATIVE DETERMINATION OF ASBESTIPORM AMPHIBOLE MINERAL
CONCENTRATIONS IN WESTERN LAKE SUPERIOR WATER SAMPLES
P. H. Cook
National Water Quality Laboratory, U. S. EPA
Duluth, Minnesota 55804
ABSTRACT
The amphibole mineral, cunmingtonite-grunerite, has been used
as a tracer for taconite tailings discharged into Western Lake
Superior. The discovery of many asbestiforra amphibole fibers in
the tailings and Western Lake Superior water lead to concern over
fiber concentrations in municipal water supplies using this water.
This concern was based on the association between human asbestos
exposure and increased rates of cancer of the gastrointestinal
tract and peritoneum. An x-ray diffraction external standard tech-
nique has been developed for rapid, inexpensive, semi-quantitative
determinations of amphibole mass concentration in water. The av-
erage amphibole mass concentrations for different Western Lake
Superior water intakes compare very well with the average electron
microscope fiber counts for the same samples. Daily amphibole
analysis of the Duluth water supply indicates an average amphibole
concentration of 0.19 milligrams per liter.
INTRODUCTION
For several years x-ray diffractometry has been the key an-
alytical technique for National Water Quality Laboratory studies of
the distribution and fate of taconite tailings which have been
discharged into Western Lake Superior at Silver Bay, Minnesota
since 1956. A major component of this 67,000 ton per day discharge,
the amphibole mineral cummingtonite-grunerite, provides an ideal
tracer for the tailings. The cummingtonite-grunerite (310) peak
at 29.1° 20 for copper K= radiation (d = 3.07 A) is not found in
x-ray diffraction patterns for natural lake sediments or suspended
557
24
-------
558
P. M. Cook
373 m«/P
LATITUDE N47M341
LONGITUDE W9-I5T
LAKE DEPTH 27> METEKS
9EBWCNT <
so-raw*
7S-100 im
Ming
FIGURE 1 X-RAY DIFFRACTION PATTERNS (COPPER RADIATION) FROM SEDI-
MENT SAMPLES TAKEN AT SUCCESSIVE 25 MM INTERVALS IN AN AREA OF
TACONITE TAILINGS DEPOSITION. CUMMINGTOKITE-GRUNERITE,
(Mg,Fe)7Si8022(OH)2, PEAKS ARE SHADED. THE (110) PEAK AT APPROXI-
MATELY 10.6° 29 IS COMMON TO MOST AMPHIBOLES
25
-------
P. M. Cook
559
solids. X—ray diffraction patterns (Figure 1) of lake water sus-
pended solids which contain taconite tailings and sediment trora
successive 25 ram sections of the lake bottom in an area of tailings
deposition show a clear gradation from large amounts of
cununingtonite-grunerite (shaded peaks) in very recent surficial
sediments to no cummingtonite-grunerite and little amphibole in the
older, underlying sediments (75-100 mm). X-ray diffraction study
of hundreds of river suspended sediment samples also indicates no
detectable cummingtonite-grunerite (<1%) and only 1-2% amphibole in
the natural sediments entering Western Lake Superior. Much or all
of the trace amphibole is the common, non-asbestiforra mineral horn-
blende.
Further indication of the recent addition of cummingtonite-
grunerite to Western Lake. Superior water is provided b\ x-ray dif-
fraction patterns of many suspended sediment samples saved from the
years 1940, 1950, and 1964 (Figure 2). All samples from 1940 and
1950 did not contain detectable amounts of cumr.ingtonite-grunerite
and little If any other ampljifaole minerals as indicated by a (110)
peak at 10.6° 29 (d = 8.34 A), All of the 1964 samples, however,
contained large concentrations of cummingtonite-grunerite as shown
by the appearance of large (110) and (310) peaks. The (110;/(310)
peak ratios for these samples are typical of these found for tac-
onite tailings samples.
0.1940
-------
560 p. M. Cook
In 1973, study of the morphology of amphibole particles in fine
taconite tailings by transmission electron microscopy revealed the
presence of many asbestiform fibers (Figure 3). The realization
that many of these cummingtonite-grunerite fibers are indistin-
guishable from amosite asbestos fibers lead to concern over the use
of Western Lake Superior water for municipal drinking water
supplies. This concern was based on the association between human
asbestos exposure and increased rates of cancer of the gastro-
intestinal tract and peritoneum (1) and daily x-ray diffraction
analyses of Duluth, Minnesota drinking water samples which indicated
the constant presence of high concentrations of taconite tailings.
Transmission electron microscope analysis of Duluth water samples
confirmed the presence of many amphibole fibers.
Since the discovery of asbestiform amphibole fibers in the
water supplies of Silver Bay, Beaver Bay, Two Harbors, Duluth, and
Cloquet, Minnesota, extensive sampling programs by the Environmental
Protection Agency and other groups have been undertaken for electron
microscope fiber counts. These analyses while in agreement with
the x-ray diffraction results, are very expensive, time-consuming,
and Imprecise. At this time fiber counts done by different lab-
oratories are not comparable and intralaboratory replicate results
usually vary by ± 50% of the mean. The amphibole fiber concen-
trations generally correlate with the. asphitule mass concentrations
determined by x-ray diffraction. Thus x-ray diffraction nonitoring
of water samples combined with occasional electron microscope fiber
counts offers a faster, less expensive, and probably more accurate
measure of amphibole fiber contamination. This technique has been
particularly useful for evaluating various filtration media's abil-
ities to remove amphibole fibers from drinking water.
AMPHIBOLE ANALYSIS OF WATER SAMPLES
Water samples from Western Lake Superior public water supplies,
normally ten liters in volume, are pressure filtered through 0.45p
•membrane fibers. When the turbidity of the sample is known, the
volume filtered is adjusted to give a 4-8 mg sediment sample. The
total suspended solids are determined by difference and a. weighing
correction applied to compensate for a small filter weight loss
due to leaching (2). Distilled water blanks are run periodically
to check for contamination. The dry membrane filter with sample is
fastened to a glass slide with a thin filia of lacquer, the filter
edges trimmed, and the slide directly examined with a Norelco ver-
tical diffractometer (copper Id radiation) with a graphite crystal
focusing monochromator.
The amphibole fibers and cleavage fragments assume a preferred
orientation such that the c-axis, which corresponds to the long
dimension of the fiber, is parallel to the filter surface. This
27
-------
P. M. Cook
561
r^ -^v*-?''' rf^'*
»,,
*' XV
*
s.
i
VV_»
3
3q-..
•>-t*.;'
'^* V
FIGURE 3 ELHCTRON MICKOCRAPH OF <2u TACONITE TAILINGS. a) LOW
MAGNIFICATION C.SC^X). fa) HIC.ilER MAGSIFICAriOX U2.500X) VIEW OF
AX AMPHIBOLE FIBER BUNDLE
causes Che (110) reflection and, to a lesser extent, the (310)
reflection intensities to 3e enhanced, permitting the detection of
trace amounts of .npliibcle. As little as 0.05 ng of <2\.
curamingtonite-grunerite produces measurable (110) and (310) peaks.
A semi-quantitative measurement of the amphibole concentration
is made by an external standard technique. This technique has been
28
-------
562 p. M. Cook
used to estimate trace amounts of chrysotile asbestos and amphibole
asbestos in dust samples on membrane filters (3,4) and fulfills the
need for rapid, standardized estimates of amphiboie concentration
in samples which are not amenable to the use of an internal stan-
dard. Three potentially large sources of systematic error had to
be considered before accepting the external standard model; varia-
bility of particle size, sample mass absorption coefficient, and
amphibole preferred orientation.
The external standard chosen for the preparation of standard
curves of x-ray peak intensity versus mass of amphibole was the
amphibole mixture found in the <2u taconite tailings. This choice
was made since the predominant amphibole in Western Lake. Superior
water is cumaingtonite-grunerita from taconite tailings and natural
amphihole concentrations in Lake Superior water are normally not
detectable by x-ray diffraction. The <2y taconite tailings were
determined by the x-ray diffraction of cumraingtonite-grunerite/
quartz mixtures to contain approximately 80% amphiboie and 20%
quartz. Most of the amphiaole is cummingtonite-grunerite with some
actinolite-tremolite. Larger size fractions of the tailings contain
less amphibole and more quartz with a small percentage of magnetite.
Reference samples were prepared by adding known amounts of the
<2u amphibole standard fo ten liter samples of Lake Superior water
having no detectable amphibole minerals. This water, obtained from
Grand Marais, Minnesota, (.oucainecl 0.4 mg/1 «uspeTd2d soliJs. which
consisted primarily of organic debris, diatoms, quartz, and clay
minerals. These standard samples were then filtered and analyzed by
x-ray diffraction in the same manner as unknown samples. The re-
sulting x-ray diffraction patterns are identical in appearance to
those for Duluth water samples.
The <2y amphibole particle size (by gravity settling) for the
external standard ^'as shown to be appropriate by a centrifugation si^e-
separation of Duluth water suspended solids from samples taken on
fifteen different days. Ninety-five percent of the suspended solids
were in the <2u fraction witn only a small amount of amphibole in
the 5% which was >2p. Thus variability in diffracted x-ray inten-
sity due to mineral particle size >2y is insignificant.
The filtration of ten liters of Duluth water normally results
in 4-8 mg of suspended solids retained on the 0.45;. membrane filter.
When the suspended solids exceed 0.3 mg/1, smaller volumes are
filtered. A sample weight of 8 rag and an average density of 2 g/cm~
results in a hypothetical sample thickness of 3u on the filter.
This thin sample thickness should preclude variability due to dif-
ferences in sample absorption coefficients. Direct evidence for
this is provided by the linearity of a plot of percent amphiboie
versus x-ray intensity for samples in this weight range; the uniform
29
-------
P. M. Cook
563
intensity of filter background in the x-ray diffraction pattern with
increasing sample weight to 10 mg; and the linearity of a plot of
quartz peak (d = 3.33 A) intensity versus weight of quartz, regard-
less of total sample weight in the range 0—12 mg.
AMPHIBOLE
(110) PEAK
X-RAY
INTENSITY
counts/second
MILLIGRAMS AMPHIBOLE L2. >j
FIGURE 4 EXTERNAL STANDARD CURVE FOR AMPHIBOLE SEMI-QUANTITATIVE
ANALYSIS
The non-linearity of the external standard curve (Figure H) is
due to a decreasing degree of preferred orientation as the ar.ount
of amphibole increases. This is indicated by decreasing araphibole
(110)/C31Q) and amphibole (.110) /quartz peak ratios with increasing
weight of the standard amphibole—quartz mixture on the filter. The
utility of the external standard curve depends on how well the curve
models amphibole preferred orientation in environmental samples.
Similar curves based on samples prepared with increased amounts of
natural sediment agreed well with the standard curve used. K'ith
large amounts of natural sediment, the amphibole peak intensity is
weakened which would cause an underestimation of amphibole concen-
trations. Other standard curves were employed to estimate the
amphibole concentration in the few samples with a very high
concentration of non-amphibole minerals.
30
-------
564 P. M. Cook
External standard curves, such as Figure 4 were plotted from
the nor.-lincar least squares refinement of araphibole mass versus
amphibole (130) peak intensity data points. The data fit an equa-
tion of the form: Ic = IQ + !«(!- exp-kC), where TC = intensity at
concentration C (mg amphibole); Io = intensity at C = 0; !„ =
intensity at C = °°; and k is a constant. This equation is consist-
ent with a model in which the degree of preferred orientation
decreases as more amphibole particles are placed on the membrane
filter. Standard curves utilizing amphibole (110) peak height above
background are identical to curves plotted from the (110) peak
areas. Both measurements are used and give the same amphibole
concentrations for environmental samples. Use of an amphibole (310)
peak curve gives the same results but with less precision due to
lower peak intensity.
Replicate (five) analyses of Duluth water samples indicate a
standard deviation of + 3% for determining amphibole concentrations
in typical samples with 0.1-0.3 mg/1 amphibole. For samples having
lower amphibole concentrations (<0.1 mg/1) and high suspended solids
(>1.0 mg/1), this precision is reduced to + 25%. Overall suspended
solids determinations have a standard deviation of + 67, of th? mean.
Detection limits for determining amphibole concentration depend on
the volume of water filtered and can be as low as 0.5 ug/1.
WATER SUPPLY AMPHIBOLE ANALYSIS
Daily analyses of Duluth water samples for amphibole and sus-
pended solids concentrations began in March 1973 and continues to
date. Results through January of 1974 are shown in Figure 5 with
climatological data and intake water temperatures. X-ray diffrac-
tion analysis provides a picture of daily and seasonal fluctuations
in amphibole and suspended solids concentrations. For example,
periods of heavy rainfall are followed by abrupt increases in
suspended solids due to river run-off and shore erosion. These
increases In suspended solids do not coincide with increases in
amphibole, indicating a different source for atnphibole sediment.
Maximum amphibole concentrations (up to 0.8 mg/1) occur in
the late fall and spring. Minimum amphibole concentrations (0.04
mg/1) occur during the late summer and early fall when a thermo-
cline is present in Western Lake Superior. The average amphibole
concentration measured was 0.19 milligrams per liter with 0.83
milligrams per liter total suspended solids.
During the period August 22-November 28, 1973, personnel from
Region V of the Environmental Protection Agency obtained weekly
water samples from municipal water supplies using Lake Superior
water from Grand Marais, Minnesota to Marquette, Michigan. These
31
-------
CO
1X3
£~ '5
lio 10
Sf *
32 o
E
NE
N
NW
•D
e W
$ SE
S
sw
I. .1 t lUftaJ t I I*.
-------
566
P. M. Cook
samples were analyzed for amphibole mass concentration at the
National Water Quality Laboratory and amphibole fiber concentration
by transmission electron microscopy at the Ontario Research
Foundation in Sheridan Park, Ontario and McCrone Associates in
Chicago, Illinois. Figure 6 depicts the average x-ray diffraction
and electron microscope measurements for each station. The agree-
ment between these two measurements is obviously very good. The
pattern of maximum concentrations at Beaver Bay and decreasing
concentrations in a counterclockwise direction around Western Lake
Superior is consistent with large quantities of amphibole fiber
discharged at a point between the Silver Bay and Beaver Bay,
Minnesota water supply intakes and then transported towards Duluth
(southwest) by the predominantly counterclockwise currents of
Western Lake Superior (5).
Comparison of NWOL X-Ray Diffraction Amphibols Analyses to EPA Region V
Electron Microscope Fiber Counts for Public Water Supply Samples
Average Concentrations for Weekly Samples Taken Aug 22-Nov 28, 1973
oia
• O44
* 040
* 036
If 03*
S 5 02«
1 or O20
^ 0.6
r°"
g OO8
J OO4
0
o
s
LL
S
o _
IB ! ~
B B o o o o 5
• B • 2 £ JL °
"3
1 » I 1 *
1 * ! 1 . « i M I »
1 1 1 1 1 1 1 1 1 1 1
13
"
II
H'
w 8
11,
CS
I'"'
a
'Ui
8
liiiliii
'S
j >. & I S 1 • -
! J i* 1 1! ! if 1
FIGURE 6 COMPARISON OF AMPHIBOLE MASS CONCENTRATION DETERMINED
BY X-RAY DIFFRACTION TO TRANSMISSION ELECTRON MICROSCOPE AMPHIBOLE
FIBER COUNTS FOR LAKE SUPERIOR WATER INTAKES
33
-------
P. M. Cook 567
ACKNOWLEDGEMENTS
The author wishes to gratefully acknowledge the assistance of
Mr. James Tucker of the National Water Quality Laboratory for
electron microscope examinations of water and tailings samples;
Mr. Robert Fulton and Mr. David Marklund for their excellent work
in preparing many of the samples examined by x-ray diffraction;
and Dr. Billy Fairless of the Environmental Protection Agency,
Region V, Central Regional Laboratory, for providing water intake
fiber counts.
REFERENCES
1. I. J. Selikoff, E. C. Hammond and J. Churg, "Carcinogenicity
of Amosite Asbestos," Arch. Environ. Health Z5_, 183-186 (1972).
2. J. G. Eaton and G. E. Likens, "Use of Membrane Filters in
Gravimetric Analyses of Particulate Matter in Natural Waters,"
Water Resources Res. _5, 1151-1156 (1969).
3. A. L. Rickards, "Estimation of Trace Amounts of Chrysotile
Asbestos by X-Ray Diffraction," Anal. Chem. 44, 1872-1373
(1972).
4. J. V. Crable, "Quantitative Determination of Chrysotile,
Amosite, and Crocidolite by X-Ray Diffraction," Am. Ind. Hyg.
Assoc. J. rt_, 293-298 (1966).
5. C. E. Adams, "Summer Circulation in Western Lake Superior,"
Proc. 13th Conf. on Great Lakes Res., 862-879 (1970).
34
-------
^sprinted from
b September 1974, Volume 185, pp. 853-855
Asbestiform Amphibole Minerals: Detection and Measurement
of High Concentrations in Municipal Water Supplies
Philip M. Cook, Gary E. Glass and James H. Tucker
Asbestiform Amphibol Minerals: Detection and Measurement of High Concentrations
in Municipal Water Supplies by Philip M. Cook, et. al., is reprinted from
Science, 6 September 1974, with permission of the American Association for
the Advancement of Science, 1515 Mass. Ave., N.W., Washington, D.C. 20005.
Copyright© 1974 by the American Association for the Advancement of Science
35
-------
Asbestiform Amphibole Minerals: Detection and Measurement
of High Concentrations in Municipal Water Supplies
Abstract. Asbestiform amphibole minerals, which have been demonstrated to
he associated with human health problems, have been detected in substantial
quantities in municipal water supplies taken from western Luke Sitpeiior water.
The total concentration of amphibole minerals in the Dulutlt. Minnesota, water
supply, as measured by x-ray diffraction for daily samples of suspended solids,
averages 0.19 milligram per liter with large fluctuations due to seasonal and dinia-
tological effects on lake circulation. Election nucioscopic examination oj these
water samples confirms the presence of asbestiform amplnhole fibers A tonseiva-
tive estimate of the fiber count for 1973 Duluth water supply samples is (! to 30}
X 10'' amphibole fibers identifiable bv election difjiaction pel liter oj watei with
a mass concentration ol I to 30 micrognims pel litci
The inhalation of asbestos fibers has
long been recognized as a serious oc-
cupational and environmental health
problem. Moreover, excessive rates of
gastrointestinal and peritoneal cancer
are associated with occupational ex-
posure to asbestos (/). Recently it has
been suggested that the ingestion of as-
bestiform minerals causes an increased
incidence of gastrointestinal cancers
(2). The presence of asbestiform par-
ticles in parenteral drugs (J), beverages
(4, 5), food (6), and drinking water
(5, 7) has been reported, and the mi-
gration of these fibers through the rat
bowel wall has been demonstraled by
several workers (8). The rapid trans-
port of large intact starch granules and
other particles throughout the human
body after ingestion has also been re-
ported (9).
Although natural sources of asbesti-
form minerals are known !o contribute
to fiber concentrations in drinking
water, particularly in areas of serpen-
tine rock, industrial discharge and min-
ing operations can also produce high
concentrations of asbestiform minerals
in drinking water supplies (7). The con-
tribution to water supplies from asbes-
tos-cement pipe is now being studied by
the Environmental Protection Agency.
,0-5 P", *«f
Fig. 1. Electron micrographs of amphibole fibers filtered from Diiluth drinking water:
(a) fiber approximately 2.2 /^m long and 0.04 ^m wide; (b) fiber approximately 2.9 /^m
long which is a bundle of many individual fibrils. Amphibole fibers are present with
other minerals, diatoms, and organic detriuis; thus it is difficult to identify all the
amphibo'e fibers
Such contamination is invariably due to
chrysotile asbestos, since approximately
95 percent of the asbestos fiber used in
North America is chrysotile (10}. Other
asbestos minerals, all of which arc in
the amphibole group of hydrated sili-
cates, include amosite, crocidolite, an-
thophyllite, trcmohte, and actinolite.
We report here the discovery of as-
bestiform amphibole fibers in public
water supplies taken from western Lake
Superior water. We have studied the
variations in the concentration of as-
bestiform minerals in this water over
the past year by x-ray diffraction and
electron microscopic techniques. The
predominant amphibole present is cum-
mingtomte-grunerite, which is repre-
sented by the formula (Mg>Fe)7SiNO.j;>-
(OH)j. The asbestiform cummingtonite-
grunerite of commercial importance is
amosite. In addition, smaller amounts
of tremolite-actinolite and hornblende
are found in the amphibole fraction of
suspended solids filtered from western
Lake Superior water. The concentration
of amphibole (//). particularly cum-
mingtonite-grunerite, was found to be
below detection limits (< 0.02 ing/liter)
at Thunder Bay, Ontario, and Grand
Marais, Minnesota; detectable at Silver
Bay. Minnesota, high O 0 1 mg/liter)
at Beaver Bay. Two Harbors, and
Duluth, Minnesota, and detectable in
Cloquct. Minnesota water, which is
also used bv Superior. Wisconsin
Examination of samples of suspended
solid« from the Duluth water supply by
transmission electron microscope re-
veals the presence of diatom fragments,
organic debris, quartz particles, some
clay minerals, and amphibole particles
ranging from blocky cleavage fragments
to ashestiform fibers (Fig 1). High-
magnification electron micrographs (Fig.
Ib) show that many fibers consist of
••mailer fibers, or fibrils, held together
in bundles. The bundle nature, the
lineation observed owing to the presence
of fibrils within the fiber, and the
ragged ends of the fibers have all been
listed as criteria for the morphological
identification of asbestos fibers by
transmission electron microscopy (12).
Although amphibole fibers as long as
20 iim have neen observed in Duluth
36
-------
•vater samples, most are less than 5 ^m
long with many less than 1 /j.m long.
There has been considerable debate
(13) over the carcmogenicity of in-
haled asbestos fibers smaller than 5
/>m, although occupational and environ-
mental exposure to asbestos which re-
sults in cancer invariably involves more
fibers smaller than 5 /im than fibers
larger than 5 /im. Less is known of the
significance of fiber length when the
fibers are ingested.
Amphibole fiber counts by electron
microscopy (14) showed millions of
amphibole fibers per liter in samples of
Duluth water. The amphibole-like
fibers may be positively identified by
their selected-area electron diffraction
patterns (SAED). For reasons of size,
orientation, or particulate interference
many amphibole fibers do not provide
diagnostic diffraction patterns, and thus
not all (he fibers present were counted.
The presence ot some chrysotile fibers
was also noted.
A comparison of the analysis of the
water samples by x-ray diffraction and
electron microscopy permits the estima-
tion of fiber counts for other Duluth
water samples The comparison rests
on the assumption that the mass of
total amphibole present is related to the
number of amphibole fibers. This re-
quires a constant particle size distribu-
tion for the samples compared, as was
observed for the Duluth water samples.
We estimate a range of (1 to 30) X 106
SAED identified amphibole fibers per
liter of water with a mass concentra-
tion of 1 to 30 /ig/liter. The concentra-
tion of fibers in the drinking water
vanes with lake conditions and tends to
decrease with the increasing residence
time of the water in the distribution
system Occasional peak concentrations
(up to 10° fibers per liter) can result
from the resuspension of settled sedi-
ment in the water lines. These amphi-
bole asbestiform fiber counts and par-
ticularly mass concentrations are much
higher than the values reported for
chrysotile fiber contamination in 22
municipal water supplies in the Province
of Ontario (7). At Thunder Bay, which,
like Duluth, uses unfiltered Lake Supe-
rior water, 0.8 X 10" chrysotile fibers
per liter with a mass concentration of
0.0002 /ig/liter were found.
The daily variations in the amphi-
bole concentrations of Duluth water
supply samples, as calculated from the
amphibole x-ray diffraction peaks (11),
are depicted in Fig. 2. During 1973,
the amphibole concentrations varied
from 0 03 to 0 80 mg/liter with a mean
concentration of 0.19 mg/liter. The
S W
SE
S
c swt
o
S ~ 30
,*. . . i . .1*1 li it, tt I, iJl ..* J,,]
• . . . 1
I . I i .Ik i. i.i . . . i I . . ]
bill, . i u W til' i It, II I 11.. Ill I ., l I i. ]
I !•,. it .« n II I k< I «t I. < i . Hull i I ti ii I n hM ill
I I .1.1 I* i.lllillll I h I lllli I.
> I I I I ill . I J II k ill I U J . . , .1
\t II I I I I.I III. I.I.I iJ, J .1 II III «
E r i. .. § id*! i i it.
NE i, . i.l. . I
N
NW
- — 3 °t I I
a E 2 of i ..J I
§- I0li, _,L.-.I, L. l.a..L....,ull,. i .,J I
Jan Feb March April May June July Aug Sept Oct Nov Dec Jan
1973
Fig. 2 Results of analyses (lanuary 1973 through January 1974) of 10-liter Duluth,
Minnesota, drinking water samples for amphibole and suspended solid concentrations.
Dailv sampling began on 19 March 1973. The dashed plot for prior dates indicates
the penod of less frequent sampling Measinements of the concentrations of suspended
solids were not made on samples taken before d Maich Resultant wind direction and
speed (vMiid scale, 0 to 30 km hour) anci precipitation data are the values as reported
by the U S Department ot Commerce. National Oceanic and Atmospheric Administra-
tion, National Weather Service, for Dnlulh Inte; national Airport. Daily mean water
temperatures aie calculated from houily Duluth water intake tempeiature data provided
by Ihe Duluth Water and Gas Department l.akeuood pumping station. Climatological
events which alleet Ihe amount and mineralogical nature of the suspended solids noi-
inullv pierede the observed change in \valer cniahtv r» ) to 2 days
mean percent (by weight) of the sus-
pended solids identified as amphibole
was 23 percent.
The effect of Climatological condi-
tions on the amount and mineralogical
nature of the suspended solids in the
Duluth water supply is most evident
when heavy rainfalls are followed by
an increase in the amount of suspended
solids resulting from river runoff and
shore erosion. On 24 May, for example.
4.! cm of rainfall was recorded; this
was followed by a brief period, begin-
ning on 26 May, characterized by high
concentrations of suspended solids in
the Duluth water supply. The lag time
represents the time needed for the river
runoff to move downshore to the water
intake. These storm-caused high con-
centrations of suspended solids have low
percentages of amphibole; this finding
was expected, since our study shows
that suspended river sediments enter-
ing Lake Superior contain only 0 to 3
percent amphibole, mainly hornblende.
The prevailing water circulation in
western Lake Superior is known to be
counterclockwise (/5), consistent with
the pattern of progressively increasing
amphibole concentration which we find
in lake water to the northeast of
Duluth. The Duluth water intake, lo-
cated at a depth of 20 m, may receive
water with increased amphibole concen-
tration when the surface water circula-
tion from the northeast is promoted
by extended periods of easterly and
northeasterly winds, as during the pe-
riods of 29 March to 9 April, 29 April
to 1 May. and I to 7 May. These same-
winds may also cause the resuspension
of recently settled amphibole-nch sedi-
ment by wave action in the shallow
water area around the water intake.
A period characterized by very high
concentrations of suspended solids (ap-
proximately 20 percent amphibole) oc-
curred in December 1973 when strong
easterly winds resuspended surface sedi-
ments and the river sediment input was
low. Ice cover, which normally begins
in January, prevents such wind-gen-
erated resuspension of lake sediment.
Amphibole concentrations in Duluth
water diminish during the period of
increasing summer stratification of
western Lake Superior water until fall
overturn (the time period in Fig. 2
when -vater temperatures were greater
than 4°C), probably because of the de-
creased circulation of deeper lake water
from the northeast. During times of
isothermal conditions without ice cover
this circulation is more pronounced, and
thus the peak amphibole concentrations
37
-------
occur in spring and late fall. Changes
of water temperature at the intake dur-
ing the months of summer stratification
are often wind-related. Offstore winds
(westerly or northwesterly) can cause
upwelling which brings colder water to
the intake such as on 6 and 11 Septem-
ber. Easterly or northeasterly winds dur-
ing the months of stratification push
warm surface water into the Duluth
water intake area, causing higher water
temperatures such as on 24 July.
A historical record of the types of
amphibole minerals previously sus-
pended in Lake Superior water may be
derived from a study of the bottom
sediments. Dell (16) reported horn-
blende as the predominant amphibole
in the sand fraction of Lake Superior
postglacial sediments with a trace of
tremolite-actinolite also present in some
cases. Our study (17) of the surficial
sediments of western Lake Superior
shows a clear pattern of a recently de-
posited sediment layer rich in cum-
mingtonite-grunerite on top of older
sediment which does not contain de-
tectable amounts « 1 percent) of cum-
mingtonite-grunerite. This layer rich in
cummingtonite-grunerite is thickest (90
m or more) and coarsest in the vicinity
of a large taconite tailings discharge at
Silver Bay, Minnesota (18). It spreads
throughout much of western Lake Su-
perior, becoming thin and diluted with
other sediment at Duluth, which is at
the western tip of the lake. Indication
of recent changes in the mineralogy of
suspended solids in western Lake Su-
perior water is provided by our x-ray
diffraction analysis of suspended sedi-
ment samples collected for several pe-
riods in the past by the City of Duluth
water utility. Samples from 1939-1940
and 1949-1950 contain only trace
amounts of amphibole with no detect-
able cummingtonite-grunerite, but all
samples studied for the period 1964—
1965 contained large amounts of am-
phibole (average, 31 percent of the
total inorganic solids), most of which
was cummingtonite-grunerite. The geo-
logical and limnological data indicate
that the source of this large increase in
amphibole material is the taconite tail-
ings (18) that, since 1956, have been
discharged into western Lake Superior
at Silver Bay.
PHILIP M. COOK
GARY E. GLASS
JAMES H. TUCKER
U.S. Environmental Protection Agency,
National Water Quality Laboratory,
6201 Congdon Boulevard,
Duluth, Minnesota 55804
Refmacei ud No«c<
1. E. E. Keal, Lancet 19fO.II, 1214 (1960); I. I.
Selikoft, J. Churg, E. C. Hammond, /. Am.
Med. Assoe. US, 142 (1964); P. E. Enterline
and M. A. Kendrick, Arch. Environ. Health
IS, 181 (1967); I. I. Selikoff, E. C. Hammond,
J. Churg, /. Am. Med. Assoc. 204. 106 (1968);
M. L. Newhouse and J. C. Wagner, Br. J.
Ind. Med. M, 302 (1969).
2. Joint National Institute of Environmental
Health Sciences-Environmental Protection
Agency Conference on Biological Effects of
Ingested Asbestos, Durham, North Carolina,
18-20 November 1973.
3. W. I. Nicholson, C. J. Maggiore, I. J. Selikoff,
Science 177, 171 (1972).
4. C. L. Berry, Nature (Land.) 21», 93 (1968).
5. H. M. Cunningham and R. D. Pontefract,
Ibid. 232, 332 (1971).
6. R. R. Merliss, Science 173, 1141 (1971); H. E.
Blejer and R. J. Arlon, /. Occup. Med. IS,
92 (1973).
7. O. Kay, Water Pollut. Control 111, 33 (1973).
8. G. E. Westlake, H. J. Spjut, M. N. Smith,
Lab. Invest. 14, 2029 (1965); R. D. Pontefract
and H. M. Cunningham, Nature (Land.) 243,
352 (1973); H. M. Cunningham and R. D.
Pontefract, I. Assoc. Off. Anal. Chem. 56, 976
(1973).
9. C. Volkheimer and F. H. Schulz, Qual. Plant.
Mater. Vtg. 18, 17 (1968); G. Schreiber, Arch.
Environ. Health W, 39 (1974).
10. S. Speil and J. P. Leineweber, Environ. Res.
2, 166 (1969).
11. By x-ray diffraction analysis of suspended
solids filtered from 10-liter water samples, we
made semiquantitative estimates of the amphi-
bole concentration with the use of an external
standard. This technique has been used to
estimate trace amounts of chrysotile asbestos
and amphibole asbestos in dust samples on
membrane filters [A. L. Rickards, Anal. Chem.
44, 1872 (1972); J. V. Crable, Am. Ind. Hyg.
Assoc. 1. 27, 293 (1966)] and fulfills the need
for rapid, standardized estimates of amphibole
concentration in samples that are not amenable
to the use of an internal standard.
12. P. Gross, R. T. P. deTreville, M. N. Halter,
Arch. Environ. Health 20, 571 (1970).
13. Doubts about the carcinogenicity of smaCl-
fibers stem primarily from the absence of
tumors in animals subjected to short fibers.
A recent study [F. Pott, F. Huth, K. H.
Friedricks, Zentralbl. Bakterlol. Parasitenkd.
Infektlonskr. Hyg. Abt. I Orlg. 15S (5/6), 463
(1972)], however, reported that rats intra-
peritoneally injected with chrysotile fibers in-
curred about a 40 percent incidence of tumors
for two different tests with small fibers (95
percent less than 5 tan and 99 percent less
than 3 /an).
14. The fiber counts were carried out by the
Ontario Research Foundation (ORF), Sheridan
Park, Ontario. A comparison with literature
values is normally not possible since different
preparation and counting methods are often
used. Because ORF results have been reported
for other water samples (7), these values can
be compared with those results. The ORF
fiber-counting technique consists of filtering
the water sample with a 0.1-nm membrane
filter, ashing the filter by maintaining it at
450°C for 3 hours, dispersing the ashed
sample in 4 ml of distilled water, and cen-
trifuging a 1-ml aliquot onto a carbon-coated
electron microscope grid which is examined
at X 25,000 magnification on a transmission
electron microscope (Jeolco model JEM 100U)
at 80 kv. The Environmental Protection Agen-
cy is currently developing a standard method
for the counting of asbestos fibers in environ-
mental samples.
15. C. E. Adams, Proc. 13th Con/. Great Lake*
Res. (1970), p. 862.
16. C. I. Dell, "Late Quaternary Sedimentation
in Lake Superior," thesis, University of Michi-
gan (1971).
17. P. M. Cook G. E. Glass, R. W. Anu.cw, in
preparation; R. W. Andrew and G. E. Glass.
in Proceedings of a Conference on the Matter
of Pollution of Lake Superior (U S. Depart-
ment of Interior-Federal Water Quality Ad-
ministration hearings, 2nd session, April 1970)
(O-401-869, Government Printing Office, Wash-
ington, D.C., 1970), vol. 1, PP. 226-250.
18. Cummingtonite-grunerite is found almost ex-
clusively in metamorphic rocks, usually in
metamorphosed iron formations. The eastern
Biwabik iron formation in northeastern Min-
nesota has been contact-metamorphosed by
the Duluth gabbro. B. M. French [M/nn.
Geol. Sun. Butt. 45, 1 (1968)1 has described
in detail the formation of cummingtonite-
grunerite in the metamorphosed iron forma-
tion near the Duluth gabbro. This cumming-
tonite-grunerite in many cases is acicular to
asbestiform in habit and varies from iron-rich
grunerite to magnesium-rich cummingtomte.
(The infrared spectrum of a sample of cum-
mingtonite-grunerite from the taconite iron
ore body is identical to that of amosite as-
bestos. The infrared interpretation technique
described by R. G. Burns and R. G. J.
Strens [Science 153, 890 (1966)] for cumming-
tonite-grunerite indicates that both samples
have an FeAFe + Mg) atom ratio of 0.76.)
The taconite iron ore body has been mined,
and, after the extraction of magnetite, the
amphibole-rich tailings have been discharged
since 1956 into western Lake Superior at
Silver Bay, Minnesota.
25 January 1974; revised 31 May 1974
38
-------
APPENDIX G UNIVERSITY OF MINNESOTA AT DULUTH ELECTRON MICROSCOPE
ANALYSIS RESULTS OF PILOT WATER TREATMENT UNITS -
RAW WATER FROM DULUTH LAKEWOOD INTAKE.
f/1 x 10°
Date of
sample
6/13
6/13
6/13
6/13
6/17
6/17
6/17
6/17
6/17
6/24
6/24
6/24
6/24
6/24
6/28
6/28
6/28
6/28
6/28
7/3
7/3
7/3
7/3
7/3
7/19
7/19
7/19
7/19
7/19
7/23
7/23
7/23
7/23
7/23
7/25
7/25
7/25
7/25
7/25
7/30
7/30
7/30
Filter
utilized
MM-1
MM-2
ERD-1
MM-1
MM-2
BIF
ERD-1
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
Run Raw
No. sample
33.25
36
57
1
10.64
39
61
31
4
6.03
44
71
37
22
5.54
48
76
47
28
2.99
52
78
51
32
266.0
67
96
70
40
26.0
70
99
72
41
60.5
72
101
73
43
26.6
74
105
Finished
sample
0.53
0.07
6.93
0.23
0.41
7.59a
7.07a
0.92
0.825
8.17a
1.85a
0.51
0.53b
0.83
0.73
0.91
0.16
1.96
1.22
0.66
0.95
2.00
4.16
0.35
0.23
4.41
2.04
0.46
0.43
0.921
0.964
0.18
0.10
Per Cent
Removal
98
99
79
98
96
—
66
85
86
—
69
91
90
85
87
69
95
34
59
—
—
—
—
99
99
83
92
99
99
99
98
99
99
39
-------
APPENDIX G (CONTINUED).
Date of
sample
7/30
7/30
7/31
7/31
8/1
8/1
8/1
8/1
8/1
8/6
8/6
8/6
8/6
8/6
8/8
8/8
8/8
8/8
8/8
8/13
8/13
8/13
8/13
8/13
8/15
8/15
8/15
8/15
8/15
8/20
8/20
8/20
8/22
8/21
8/22
8/22
8/23
8/23
8/23
8/28
8/28
8/28
8/30
8/30
8/30
8/30
Filter
utilized
BIF
ERD-2
MM-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-1
MM-2
BIF
ERD-2
MM-2
ERD-2
MM-1
MM-1
MM-1
MM-2
ERD-2
MM-2
BIF
MM-2
BIF
ERD-2
Run
No.
77
45
106
76
107
79
46
78
109
82
48
80
111
84
49
82
113
88
51
84
114
89
55
118
59
86
86
86
119
63
122
103
124
105
68
f/1 x 106
Raw Finished
sample sample
1.01
0.87
106. 6b
0.64b
30.0
0.72
0.14
1.70
0.79
10.2
0.20
0.19
0.42
2.00
15.1
0.45
0.16
1.52
0.34
20.0
0.38
0.37
0.59
0.51
8.98
0.55
0.43
1.27
1.53
25.3
0.15
0.81
13.6
0.31
0.49
0.37
17.0
0.26
1.71
10.4
0.11
1.05
17.8
0.18
0.65
0.29
Per Cent
Removal
96
99
99
98
99
94
97
98
98
96
80
97
99
90
98
98
98
97
97
94
95
86
83
99
97
98
96
97
98
90
99
90
99
96
98
40
-------
APPENDIX G (CONTINUED).
Date of
sample
9/4
9/4
9/4
9/4
9/6
9/6
9/6
9/6
9/9
9/9
9/9
9/10
9/10
9/11
9/11
9/11
9/13
9/13
9/13
9/13
9/16
9/16
9/16
9/16
9/17
9/17
9/19
9/19
9/19
9/19
9/20
9/20
Filter
utilized
MM-2
BIF
ERD-2
MM-2
BIF
ERD-2
BIF
ERD-2
MM-2
MM-2
BIF
MM-2
BIF
ERD-2
MM-2
BIF
ERD-2
MM-2
MM-1
MM-2
BIF
ERD-2
a Value may be in error due
Cloquet
Pipeline water
Run
No.
126
108
70
128
111
72
113
73
131
133
115
137
117
78
138
118
79
139
87
140
120
85
to DE present
f/1
Raw
sample
30.3
13.6
15.4
—
13.0
30.0
20.3
12.8
13.8
19.1
in sample
x 106
Finished
aample
0.33
0.96
0.70
0.17
0.36
0.26
0.33
0.64
0.27
0.30
0.28
0.24
0.47
0.51
0.51
4.89
0.81
0.64
1.46
0.33
0.76
0.45
Per Cent
Removal
99
97
98
99
97
98
98
96
—
98
98
99
98
98
97
76
96
95
89
98
94
98
41
-------
266
K3
1C
O
100
90
80
70
X
-------
UNIVERSITY OF MINNESOTA School of Medicine
DULUTH ; ?205 East 5th Street
• Duluth, Minnesota 55812
September 19, 1974
Mr. 0. John Schmidt
Black & Veatch
Consulting Engineers
P. 0. Box No. 8405
Kansas City, Missouri 64114
Dear-Mr. Schmidt:
I am pleased to forward the following description of the methods by which we have
been counting fibers here at the School of Medicine in Duluth.
Water samples were obtained from Black & Veatch Engineers at the Lakewood Pumping
Station for the City of Duluth. The code information on each bottle was recorded
and the bottles were then assigned random numbers in order to "blind" personnel
involved in the subsequent steps of the analysis. The code was not broken until
counting of all samples from a given week or weeks was completed.
Two-hundred millileters of each sample were filtered through Nuclcoporc* filters
with pore size of 0.2 microns. Particulate matter within the sample was collected
on the dull surface side of the membrane filter, and a sediment faintly visible to
the naked eye was observed with the majority of samples filtered. The filter was
air dried and placed in a sealed plastic container until electron microscope grids
were prepared.
At the time of grid preparation, each filter was cut in half with a fine scissors.
One-half was returned to the plastic container for possible future use. The other
half was inverted on two randomly placed copper electron microscope grids which
had been placed on six layers of filter paper in a clean glass petri dish. The
EM grids had been covered with a Formvar plastic film followed by a carbon coating.
A single drop of chloroform was placed on the filter membrane over each grid
position, fixing that portion of the membrane firmly to the surface of the coated
grid. The filter paper in the petri dish was then saturated with chloroform to
dissolve the remainder of the plastic filter, leaving the filtered particulate
matter adhering to the coated surface of the grid.
Fibers were enumerated using a Philips Series 200 Electron Microscope at 10,000 X
magnification. Any particle with nearly parallel sides, square ends, and an aspect
ratio of 3 to 1 or greater was counted as a fiber. Electron diffraction was per-
formed on a sufficient number of particles in each sample to ascertain that fibers
of a given morphologic appearance had a crystalline diffraction pattern typical of
chrysotile or amphibolc asbestos.
\
43
-------
Mr. 0. John Schmidt
September 19, 1974
Page Two
Both of the grids prepared from a sample were studied. Particle enumeration continu
until at least 25 fibers had been seen or until at least 20 grid squares along an
equatorial plane had been studied. The total number of fibers seen in each grid
square studied were recorded and averaged for the two grids from each filter.
Appropriate mathematical factors were applied to convert particles seen into fibers
per liter based upon the volume of water filtered and the cross-section area of the
grid examined.
Agreement between the replicate samples averaged plus or minus 15 per cent and the
analysis of the variance indicated that the correlation between the replicate
samples was significantly greater than would have been expected by chance alone.
Sincerely yours,
Robert E. Carter, M.D.
Dean
REC:mk
44
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
DEPORT NO. 2.
EPA-670/2-75-050e
TITLE AND SUBTITLE
DIRECT FILTRATION OF LAKE SUPERIOR
WATER FOR ASBESTIFORM FIBER REMOVAL
Appendixes E, F, and G
\UTHOR(S)
Black § Veatch, Consulting Engineers
'ERFORMING ORGANIZATION NAME AND ADDRESS
Black £ Veatch, Consulting Engineers
1500 Meadow Lake Parkway
Kansas City, Missouri 64114
SPONSORING AGENCY NAME AND ADDRESS
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
SUPPLEMENTARY NOTES
This work conducted through interagency agreement betwe
of Engineers, St. Paul District. See also EPA-670/2-75
3. RECIPIENT'S ACCESSIOWNO.
5. REPORT DATE
June 1975; Issuing Date
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
1CB047; ROAP 21AQB; Task 024
1 1 . CONTR ACT/SKAN* NO.
DACW 37-74-C-0079
IAG #EPA-IAG-D4-0388
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
en EPA Region V and the Corps
-050a, b, c, d, f, and g.
Pilot plant research conducted in 1974 at Duluth, Minnesota, demonstrated that
asbestiform fiber counts in Lake Superior water could be effectively reduced by
municipal filtration plants. During the study engineering data were also obtained
for making cost estimates for construction and operation of both granular and
diatomaceous earth (DE) filtration plants ranging in size from 0.03 to 30 mgd.
Data provided to the contractor by the Ontario Research Foundation are presented
in Appendix E. ORF performed asbestiform fiber analysis of water samples by the
transmission electron microscope method in this project. In order to place the
data in better perspective, a description of the analytical method used by ORF is
reproduced in Appendix E. In Appendix F, the amphibole mass data obtained by the
National Water Quality Laboratory in Duluth are presented. This appendix also
includes information on the analytical method used at NWQL. The x-ray diffraction
analysis for amphibole mass provided confirmation of electron microscope amphibole
fiber results. Fiber count data obtained at the University of Minnesota at Duluth
are tabulated in Appendix G. A statement describing the electron microscope
analytical method is also included.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Asbestos
Amphiboles
Serpentine
Water supply
Filtration
Water treatment
Pilot plants
DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
b. IDENTIFIERS/OPEN ENDED TERMS
Mixed media filtration
Diatomaceous earth fil-
tration
Asbestiform
Chrysotile
Fiber removal
Duluth (Minnesota)
Lake Superior
19. SECURITY CLASS (This Report)
UNCLASSIFIED
20. SECURITY CLASS (This page)
UNCLASSIFIED
c. COSATI Field/Group
13B
21. NO. OF PAGES
51
22. PRICE
Form 2220-1 (9-73)
45
U. S. GOVERNMENT PRINTING OFFICE: 1975-657-59VS39B Region No. 5-II
------- |