Document nkYojJxDq4n31KONVoBB35x2X
FILE NAME: Cassiar Asbestos Corp (CASS)
DATE: 1975 Mar 10
DOC#: CASS003
DOCUMENT DESCRIPTION: Govt Inspection Report - Airborne Concentrations of Asbestos Fibres in Mine, Mill & Townsite of Cassiar Asbestos - Clinton Creek
AIRBORNE CONCENTRATIONS OF ASBESTOS FIBRES IN THE MINE, MILL AND TOWNSITE OF
.CASSIAR'ASBESTOS CORPORATION LIMITED AT
CLINTON CREEK YUKON TERRITORY
J.P. Windish, D, MacGregor, A.B.C. Davey, W.W. Reid, Health Effects Division
Bureau of Health Hazards, (Air and Water) Health Protection Branch
Department of National Health and Welfare and
A.N. Patrick Environmental Enqineer Department of Indian and Northern Affairs
Reference HHAW 75-1 March 7th, 1975
Revised March 10th, 1975
ACKNOWLEDGMENT
We wish to thank Mr. Marcel DeRouin, Mine Manager of the Clinton Creek operation?and the members of his staff for their kind cooperation and assistance which greatly facilitated our work.
AIRBORNE CONCENTRATIONS OF ASBESTOS FIBRES IN THE MIME, MILL AND TOWNSITE OF CASSIAR ASBESTOS CORPORATION LIMITED _________ AT CLINTON CREEK, YUKON TERRITORY_______________
INTRODUCTION
This survey was conducted at Clinton Creek during the period June 18-25, 1974 at the request of the Department of Indian and Northern Affairs.
In June 1974 the Company employed 317 persons at Clinton Creek, distributed as follows:
Administration and services
81
Maintenance
111
Mine
51
Mill
74
The total population of the townsite was 415, including 88 children.
SURVEY PROCEDURE
Samp!ing Samples of airborne particulates, including asbestos fibres,
were collected on membrane filters which were contained in ooen-faced plastic holders (Millipore Monitors). Air was drawn through each filter at a known rate, for a measured period of time, by means of a small batteryoperated pump connected to the Monitor by rubber tubing.
Two types of samples were collected - personal samples and stationary samples. Personal samples were obtained by fastening a Monitor
. 2/
-2 -
to the front of a worker's shirt collar and cliopina a pump to his belt. The worker wore this equipment continuously durinq the sampling period. This type of sample gave an estimate of the amount of asbestos fibre in the air in the worker's breathinq zone. Stationary samples were obtained by fastening a sampling unit (at a height above the floor which approxi mated a man's breathing level) to a post or other fixed object in a particular area. Such a sample gave an estimate of the amount of asbestos fibre being dispersed into the air by the equipment or processes located in that area; or being carried into that area by air coming from other areas. In many instances, stationary samples were collected in nlaces where no person was regularly stationed; instead, such places would be visited by a worker from time to time, either for routine inspection purposes or to correct some fault or malfunction that had occurred.
In addition to determinations of occupational exposure to asbestos, measurements were also made of the amount of asbestos in the air in the townsite which was about eiqht miles (13 km) southeast of the mine and mill. Most of such samples were stationary samples, collected over eiqht-hour periods inside various buildings in the townsite.
Determination of asbestos fibre concentration The membrane filters were fixed (to prevent fibres being dislodged)
and mounted on microscope slides, using the British method ("Hyqiene standards for chrysotile asbestos dust." Committee on hyqiene standards of the British Occupational Hyqiene Society. Published in The Annals of Occupational Hyqiene, vol. 11, op 47-60, April 1068). The asbestos fibres on the slides were then counted using phase-contrast microscopy at
. . 3/
- 3 -
450x magnification. All the membrane filters were fixed at Clinton Creek.
About
one-third of these were mounted and counted at Clinton Creek; the remainder
were brought back to Ottawa for mounting and counting.
HYGIENE STANDARD FOR CHRYSOTILE ASBESTOS OUST There is growing agreement among occupational health workers
that, for a 7 or 8-hour workday and 40-hour workweek, the time-weiqhted average concentration of asbestos to which workers are exposed should not exceed 2 fibres per milliliter of air (2 fpml). For purposes of this standard, a fibre is defined as a particle whose length is between 5 micro-meters Qjm) and 100 ^im and whose length-to-breadth ratio is at
least 3:1. This is the standard with which data here beina reported will be
compared.
,
DISCUSSION OF RESULTS
Data for all samples collected are given in Tables A-l, A-2, A-3 (Appendix). Table A-l lists data for personal samples collected in the mill and mine; Table A-2 for stationary samples collected in the mill; Table A-3 for samples collected in the townsite.
The acceptable level of exposure (2 fpml) refers to a timeweighted average (TWA) concentration based on a 7 or 8-hour working day. This reguires that a worker's exposure be measured, as far as possible, over a full working shift. In some cases this could be done by collecting only one sample, taken continuously throughout the shift. However, if a
. . 4/
-4 -
membrane filter was too heavily loaded with fibres or with dust (particles whose lenqth-to-breadth ratio was less than 3:1, or whose length was less than 5 jjm), accurate fibre counting was not possible. To minimize the possibility of such overloading, in many cases where the exposure of a worker was being determined, a series of separate, short-term samDles was collected over the full shift and a TWA concentration calculated from the individual results (for examDle, in Table A-l, Item no.'s 27-31 are individual samples and Item no. 32 is the calculated TWA concentration).
In spite of these precautions, some samples were found to be overloaded, usually because of the presence of a great deal of fine dust, which obscured the fibres. In such cases, a probable minimum value for the concentration was calculated, on the assumption that there were probably at least 8 fibres per microscope field. This is a conservative assumption; on a filter that was not overloaded with dust, it was possible to count accurately as many as 12-15 fibres per field. In the Tables such concentrations are expressed as "Probably greater than - ".
Within any one occupational group, such as payloader operators, baggers, sewers, floormen, etc., more than one TWA determination was usually made. By averaginn all the TWA concentrations obtained for any one occupational group, the overall TWA concentration for that group was obtained. These overall averages are given in the following table:
. . 5/
- 5-
TABLE 1. Overall Time-Weighted Average Fibre Exposures for Various Occupations in the Mill
Occupation
Number of Values Averaged
Overall Time-Weighted Average Concentration
(fpml)
Payloader operator (Dryrock
Storage)
2
FIoorman
6
Labourer, tailings area
1
Concentrator (dryer) helper
4
Mill operator
3
Forklift operator
2
Mechanic
4
Shift foreman
2
Foreman
1
Bagger
10
Sewer
3
Concentrator operator
4
Screen repairman
1
Palletizer
3
Foreman, tailings area
1
Machinist
1
6.4 > 5.4 (see "not > 4.0 > 3.8
3.4 3.1 2.9 > 2.8 2.7 2.7 2.5 . 2.5 2.4 2.1 1.2 0.6
Note: ii^ = greater than.
. 6 .
During mining operations, samples collected on any one day for any particular occupation did not cover a sufficient portion of the day to permit the calculation of a truly representative TWA concentration. A rough estimate of the overall average concentration during a particular operation was therefore obtained by taking a simple average of all the individual, short-term values obtained for that operation throughout the survey. Results are given in Table 2.
TABLE 2. Approximate Average Fibre Concentrations __________ _____________During Mining Operations _________________________ _
Occupation
Number of Sample Values Averaged
Approximate Average
Fibre Concentration (fpml)
Drill operator Drill helper Truck driver Crusher ooerator Crusher helper Tramline operator Tramline helper Bulldozer operator
2
4
4
>3.2
3
0.8
3
2.7
3
3.7
2
0.2
3
0.4
1
. 0.7
- 7 -
All the occupations in the mill, exceDt the foreman in the tailings area and the machinists, had exposures in excess of 2 fpml. The aDproximations qiven in Table 2 suggest that, in the mininq operations, drill operators and helpers and crusher operators and heloers also were exposed to concentrations qreater than 2 fpml.
It must be emphasized that respirators were provided to all workers and that, when the occasion seemed to require it, they were worn. For instance, shift foremen, foremen or floormen frequently had to remove asbestos f%ibre, as quickly as possible, from equipment that had become pluqged. In such cases, they usually were observed to wear their respirators.
Results (Table A-2, Aopendix) obtained from stationary samples, indicate that concentrations qreater than 2 fpml were common throughout the plant, and not just in areas where workers were permanently stationed.
Three samples (Item no.'s 232, 233, 234) were collected in the baghouse. The air beinq sampled had been filtered and was being recirculated to the mill. Two of these samples (both taken on the same day) showed low concentrations (0.4 and 0.6 fpml respectively) but the third (taken on a different day) had a concentration of 2.4 fpml. Probably this was due to a torn or worn-out baq, or to a loosely-connected bag. The need for more frequent maintenance is indicated.
The value of 8.0 fpml found in the secretary's office in the mill (Item no. 247) is quite inconsistent with values found elsewhere. Possibly the filter was accidentally contaminated. It is suggested that the company should take further samples in this location.
Two samdes (Item no.'s 272 and 273) collected while the bus was
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travelling between the townsite and the mill gave concentrations of 0.2 and 0.6 fpml, both of which are well below the acceptable level for occupational exposure. One personal sample (Item no. 278) representing the exposure of a man doing janitorial work in one of the bunkhouses indicated an exposure of 0.9 fDml which is also well below the hygiene standard for occupational exposure.
Results (Table A-3, Appendix) of 15 determinations made in the townsite showed concentrations of airborne fibres to range between 0 and 0.04 fpml. As no standard for non-occupational exposure to asbestos has been established to date, the health sianificance of those findincis remains undefined.
Concentrations of asbestos fibre found in the aeneral atmosohere at the tailings pile in the vicinity of the discharge from the Swivel Piler (Table A-2. Item no's 250-260) ranged from 0 to 131 foml. The wide variations in counts probably were related to variations in wind direction and velocity. Sampling times had to be kept extremely short, so that no single result can be regarded as representative of anything but the concentration at the exact sampling point durina the exact sampling period. However, as a group these 11 samples indicate that the outdoor air was being considerably polluted by this process. They are not indicative of any person's exposure because no person worked at that point while the Swivel Piler was discharging material.
It is understood that since the survey was completed, a pug mill has been put into operation so that tailings are no longer discharged as dry, dusty material.
-9CONCLUSIONS AND RECOMMENDATIONS
Time-weiqhted average exposures, to asbestos, of most occupational groups in the mill are above the recommended level of 2 fibres per milliliter of air (fpml). Data suggest that, in the mine, drillers and helpers and crusher operators and helpers are also exposed to concentrations of asbestos
above this limit. Reduction in the amounts of asbestos dispersed into the air in the
mill could be achieved by some operational and housekeeping changes. For instance, considerable asbestos spills on to the floor behind the baaqing machines and is removed by hand shovelling and sweeoinq. It is recommended that efforts be made to minimize such spillage by eliminating as many of the causes as possible. Floor cleanup, both here and throughout the mill, should be done by a vacuum cleaning system, rather than by shovelling or
sweeping. High fibre counts were obtained in the vicinity of several screens
and conveyor belts. Although the screens were enclosed and provided with exhaust ventilation, dust was observed to be leaking from several. Main taining such equipment in a leak-free condition would reduce contamination
of the air in the plant. Conveyor belts are well known as sources of dust.
Concentrations
of airborne asbestos, as determined by several stationary samples collected
in the vicinity of conveyors in the mill, indicate the need for control
measures. Methods that have been used in other plants include enclosure of
the top portion of a conveyor, coupled with cleaning of the return belt by
scrapers or by rotating brushes that bear against the head pulley; or enclo
sure of the complete conveyor. The enclosures are usually exhaust-ventilated.
As was mentioned previously, air issuinq from the baqhouse was not
always sufficiently clean, probably due to holes in bags or to loose bag
-10connections. A more careful and frequent inspection routine would minimize the occurence of such leaks, ensurinq that the air beinq returned to the mill was of acceptable quality.
Exposures of oayloader operators in the Dry Rock Storaqe Shed could be greatly reduced by providinq enclosed cabs with filtered air supply systems.
J.P. Windish Industrial Hyqiene Consultant
APPENDIX
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der mill il iter of air (fpml)
ITEM
SAMPLE
No
No
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
ASBESTOS CONC. (fpml)
Indi vidua! Timesample weighted
average
REMARKS
1
36A
20Jun
A Payloader operator
0956-1101
5.9
inside Dry Rock storage
shed
Payloader no.85. Door not closed. Sampler fixed to inside of cab at breathing zone level.
2
36B
20Jun
A
IIII
3
36C
20Jun
A
II II
4
36D
20Jun
A
II II
5
36A-36D
20Jun
A
It II
6
135A
25Jun
B
II II
7
135B
25Jun
B
II II
8
135C
25Jun
B
II It
1136-1303
1304-1408 1408-1435 0956-1435 0901-1210 1212-1320 1322-1449
7.9
6.3 11.4
3.1 4.4 11.8
Payloader no 84. Door closed. Sampler fixed inside of cab.
U II
kept to
II II
7.3
t
9
135A- 135C 25Jun
B
0901-1449
5.6
0
2A
18Jun
C Shift foreman in mill
0858-1317
1
2B
18Jun
C
II II
1317-1440
2
2A-2B
18Jun
C
0858-1440
1 .8
Man was very active in mil
1 .9
Spent most of time in
foreman's office
1.8
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (fDml)
SAMPLE No
48A
48B 48A-48B
47A 47B
47A-47B
DATE
WORKER JOB TlTLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
20Jun
D
Shift foreman in mill
0907-1011
20Jun
D
20Jun
D
20Jun
E
20Jun
F
II II
II II Foreman fn m M 1
II II
1111-1448
0907-1448 0904-1117 1117-1420
20Jun
E
IIII
0904-1420
ASBESTOS CONC. (fpml)
Individual Timesamle weighted average
not count-
able, probably
>5.6
REMARKS
Filter heavily loaded with dust making accurate fibre count impossible
2.6
Filter contained many very
small particles
probably
>3.7
2,1
3.1
Not much apparent exposure
until 1320h. Then went
twice to Swivel Piler
2.7 j
12A
18Jun
F
12B
18Jun
F
12C
18Jun
F
12A-12C
18Jun
F
15A
18Jun
G
15B
18Jun
G
15C
18Jun
G
Bagger & Floorman Floorman IIII
Bagger & floorman Floorman IIII II II .
0917-1117 1117-1339 1339-1458 0917-1458 0923-1143 1143-1342 1342-1450
2.4
Bagger until 1020H. Than
floorman for rest of shift
4.7
4.1 3.8
2.8
2.4
2.4
IRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- P expressed as fibres Der milliliter of air (fpml)
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
ASBESTOS CONC.
(fpml) Indi vidua! Time-
sample weighted
average
26
G
Floorman
0923-1450
2.6
27
H
Il II
0908-1011
4.0
28
H
Il II
1012-1107
0
29
H
Il II
1107-1214
4.9
30
H
Il II
1214-1345
3.4
31
H
Il II
1345-1457
3.6
32
H
Il II
0908-1457
3.3
33
J
Floorman
0837-1046
5.2
34
J
Il II
1046-1231
4.6
35
J
Il II
1231-1429
3.5
36
J
II If
0837-1429
4.5
37
K
FIoorman
0913-1020
4.8
38 J IlII 0937-1218 naobtlecopruonbta bly > 4.5
39
J
Il II
1218-1345
10.6
J
Il II
1347-1444
5.7
IRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- P expressed as fibres Der milliliter of air (fDml)
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
ASBESTOS CONC. (fpml)
Indi vidual Timesample weighted
averaqe
41 J Floorman 0937-1444 p>rob6.a5bly
42
L
Il II
0943-1027
11.6
43
M
Il II
1318-1608
4.1
44
N
Shift labour/Bagger 0912-1007
7.7
45
N
Il II
1008-1100
2.6
46
N
Il II
1101-1207
2.1
47
N
Il II
1207-1453
2.0
48
N
Il II
0912-1453
3.0
49
P
Il II
0919-1015
11
50
P
Il II
1015-1102
4.0
51
P
It II
1102-1204
8.2
52
P
il U
1204-1300
2.7
53
P
il II
1304-1452
3.0
2RORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PEI expressed as fibres Der milliliter of air (fpml)
WORKER JOB TITLE/WORKING p l ac e
SAMPLING PERIOD (24 hour clock)
ASBESTOS CONC.
(fpml) Individual Time-
sample weighted average
P
Shift Labor/ bagqer 0919-1452
5.4
Q
Il II
0904-1311
1.8
Q
Il II
1311-1456
1.8
57
Q
IlII '
0904-1456
1.8
58
R
Il II
0906-1306
3.8
59
R
Il II
1306-1455
6.1
60
R
Il II
0906-1455
4.5
61
T
Il II
0900-1323
3.2
62
T
Il II
1323-1453
1.8
63
T
Il II
0900-1453
2.8
64
V
Il II
0843-1036
1.9
65
V
Il II
1039-1301
1.8
66
V
It II
1304-1451
2.6 1
67
V
Il II
0843-1451
2.1
68
U
Il II
0845-1040
1.5
69
II
Il II
1042-1242
1.8
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (fDml)
SAMPLE No
40C 40A-A0C
41 42A 42B 42C 42A-42C 45A 45B 45C 45A-45C 119
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
20Jun W 20Jun W 20Jun X 20Jun Y 20Jun Y 20Jun Y 20Jun Y 20Jun Z 20Jun Z 20Jun Z 20Jun Z 24Jun Z
Shift Labor/Bagger II II II II It II II II II II II II IIII IIII IIII Itll
Shift Labor/ Bagger & Sewer
1244-1444 0845-1444 0849-1025 0853-1045 1046-1335 1337-1449 0849-1449 0858-1050 1052-1258 1300-1452 0858-1452 0916-1446
ASBESTOS CONC.
(fpml) Indi vidual Time-
sample weighted average
1.5 1.6
1.2 1.7
1.5 2.3
1.7
2.7
3.9
1.6 2.8
1.4
1.4
REMARKS
4A
18Jun S
Shift Labor/ Sewer
0902-1330
1.9
4B
18Jun S
II II
1330-1449
3.6
4A-4B
18Jun S
tl II
0902-1449
2.3
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (fDml)
TEM
SAMPLE
No
No
8A
8B
8A-8B
43A
43B
)
43A-43B
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
18Jun
U
Shift Labor/ Sewer
18Jun
U
IIII
18Jun
IJ
II It
20Jun
B
IIII
20Jun
B
IIII
20Jun
B
IIII
0910-1323 1323-1448 0910-1448 0855-1245 1246-1410 0855-1410
ASBESTOS CONC. (fpml)
Individual Timesamle weighted average
4.0
1.6
3.4
1.9
1.4
1.8
REMARKS
` 10A
18Jun
A
Shift Labor/Palletizer 0913-1112
1.3
l
10B
18Jun
A
IIII
1113-1313
2.4
4
3
IOC
18Jun
A
II II
1313-1451
2.2
4
10A-10C
18Jun
A
II II
0913-1451
1.9
5
46
20Jun AA
II II
6
11A
18Jun AB
II II
0901-1449 0915-1015
1-1
1.1
2.2
7
11B
18Jun AB
II II
8
11C
18Jun AB
II II
9
1 ID
18Jun AB
II II
1017-1116
1 .9
1118-1217
3.3
1219-1319
4.2
TABLE A-l
AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (fDml)
SAMPLE No
DATE
WORKER JOB TITLE/ViORKING PLACE SAMPLING PERIOD (24 hour clock)
1C ID IE IF 1A -IF 38A 38B 38C 38A-38C
55 134A 134B
18Jun AE 18Jun AE 18Jun AE 18Jun AE 18Jun AE 20Jun AF 20Jun AF 20Jun AF 20Jun AF 20Jun M 25Jun AF 25Jun AF
134A-134B 25Jun AF
21A
19Jun AG
Mill operator Il II Il II Il II Il II Il II Il II Il II Il II It II Il II
Concentrator (dryer) he!per
1100-1200 1200-1304 1304-1348 1348-1440 0853-1440 0841-1042 1042-1235 1235-1310 0841-1310 1211-1443 0954-1235
1238-1552
0954-1552
0909-1110
ASBESTOS CUNt. (fpml)
Individual Timesample weighted average 2.4 3.6 5.5 3.3 4.1 2.3 2.6 14.0 3.8 2.8 3.1 1 .6
2.3
not count able proba bly> 5.9
REMARKS
Changed screen on IC screen during this period inside dryer shed from 1100-1130H
!
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (fDml)
ITEM No
SAMPLE No
100
11E
101
11A-l1E
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
18Jun AB 18Jun AB
Shift Labor/Palletizer 1! 11
1319-1420 0915-1420
ASBESTOS CONC. (fpml)
Individual Timesample weighted average
4.8
3.3
REMARKS
102
14A
18Jun AC
Shift Labor/Forklift
0921-1021
2.3
operator in mill
103
14B
18Jun AC
IIII
1023-1106
3.5
104
14C
18Jun AC
11II
1123-1210
3.5
105
14D
18Jun AC
IIII
1221-1321
4.4
106
14E
18Jun AC
IIII
1321-1508
3.2
j
107
14A-14E
18Jun AC
IIII
0921-1508
3.3
108
49A
20Jun AD
II II
0910-1310
2.7
109
49B
20Jun AD
IIII
1312-1451
3.5
no
49A-49B
20Jun AD
II II
0910-1451
2.9
111
1A
18Jun AE
Mill operator
112
IB
18Jun AE
II II
0853-0957
4.0
1000-1058
6.2
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (fpml)
SAMPLE No
21B 21C 21D 21A-21D 22A 22B 22C 22D 22A-22D 97
98A
98B 98C 98A-98B
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
19Jun AG 19Jun AG 19Jun AG 19Jun AG 19Jun AH 19Jun AH 19Jun AH 19Jun AH 19Jun AH 23Jun AJ
23Jun AK
23Jun AK 23Jun AK 23Jun AK
Concentrator (dryer) tlII helper It II
Concentrator operator IIII It II IIII II II II II
1113-1232 1233-1334 1336-1459 0909-1459
0919-1115
1117-1235 1238-1338 1342-1458 0919-1458 1004-1452
Concentrator helper
II II IIII II II
not countable 1011-1058
1059-1308 1310-1441 1011-1441
ASBESTOS CONC.
(fpml)
Individual Timesample weighted average
REMARKS
4.1 12.6
4.1
^ 2.6 - 4.1 - 3.4
arobably >6.3
inside dryer shed from from 1100-1130h
8.8 $ 4.5
1.4
1.4
not countable pro bably > 1 5
Inside dryer-shed for I Ht Dryer shut down approx. 1230-1245H
In # 8 conveyor (dusty) from 1015 to llOOh.
1 .3
Sweeping floor
2.9 probably
>4.3
. <
IRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONSexpressed as fibres Der milliliter of air (forni)
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
ASBESTOS CONC.
(fpml) Indi vidual Time-
samle weighted
averaqe
141
AK
Concentrator helper
0903-1047
3.4
142
AK
IIII
1047-1353
1.9
143
AK
II II
1355-1442
4.6
144
AK
IIII
0903-1442
-
2.7
145
AJ
Concentrator operator 0855-1207
1.4
146
AJ
IIII
1208-1447
2.2
147
AJ
IIII
0855-1447
1.8
148
AJ
II II
0845-1159
1.9
149
AJ
II II
1202-1453
3.0
150
AJ
IIII
0845-1453
2.4
151
AK
Concentrator helper
0919-1204
1.0
152
AK
II II
1206-1332
3.0
153
AK
II II
1335-1448
3.3
154
AK
II II
0919-1448
2.0
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (foml)
SAMPLE No
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
ASBESTOS CONC.
(fpml)
Individual Timesamle weighted average
REMARKS
51A
20Jun
AL
Screen repairman
51B
20Jun
AL
51C
20Jun
AL
51A-51C 20Jun
AL
0915-1037 1038-1342 1342-1445 0915-1445
3.1 2.0 2.7
2.4
18A
9Jun
18B 18C 18A-18C 19A 19B 19A-19B
20A
9Jun 9Jun fl9Jun 19Jun 19Jun 19Jun 19Jun
20B
19Jun
AM Mechanic/Ground floor near dryers
AM AM AM AN Greaser (oiler)/Power
separator AN AN AP Mechanic/Ground and
6th level
AP Mechanic/ 3rd level
0852-1148
1148-1455 1457-1541 0852-1541 0856-1250 1250-1558 0856-1558 0907-1304
1307-1555
2.7
working on conveyor* ^ r
seemed dusty
1.4
5.5
2.4
1.2
1.1
1.2
2.4
Changing motor on ground
level. Working on conveyor
#28 on 6th level
2.6
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (foml)
SAMPLE No
20A-20B 23A 23B
23A-23B 31
124
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
19Jun AP Mechani c/Ground,3rd & 6th levels
19Jun AQ Mechanic/3rd level fiberizer
19Jun AQ Mechanic/6th level
0907-1555 0918-1313 1314-1535
19Jun AQ Mechanic/ 3rd & 6th Levels
19Jun AM Maintenance mechanic/ Worked at mine until
1400h. then at main
garage near office
0918-1535 1143-1547
24Jun AR Machinist/Inside machine 0913-1548 shop all day
ASBESTOS CONC. (fpml)
Individual Timesample weighted average
2.5
1.8
3.9
2.6
1.3
0.6
0.6
REMARKS
28
19Jun AS Driller's helper/Mine
1112-1225
3.0
Just starting hole in hig grade ore as sampling started. Was in and out of cab frequently. Windo' & door of cab were open
34
19Jun AT Driller's heloer/Mine
1239-1527
1.8 i11
During sampling period drilled 6i-40` holes in very high-grade ore.
35
19Jun AU Drill operator/Mine
1243-1524
. 0.44
Just starting hole as
sampling started. Drilie 61-40' holes in very high grade ore
TM] No I
table a -i
airborne asbestos fibre concentrations during mill and mine operations
expressed as fibres oer mi 1 1 Iliter of air (fpml)
PERSONAL SAMPLES
SAMPLET No
WORKER r a T T f n l T ^ n R K T N G T L S C r "SAMPLING PLKluF (24 hour clock)
ASBESTOS CONC.
(fpml) Individual Time-
sample weighted average
REMARKS
n 88 22Jun AV I Driller's helper/Mine 1259-1543 no0t.5c8ount
78
155
25Jun AW
Drill operator/Mine
I . 1342-1511
able orobably>8
hot count
79
156
25Jun AX
Driller's helper/Mine
1347-1522
able pro bably> 6.8
Drilled 2i-40' holes
Worn by AX until 1450h. then left running in mine office until 1522, at which time floor was bein< swept
180
181 182
183 184 185
29
80 81
30 33A 33B
19Jun AY
22Jun AY 22Jun AZ
Truck Driver/Hauling ore from mine to crusher
1129-1435
1008-1402 1012-1443
19Jun BB 19Jun BC 19Jun BC
Crusher operator/Mine
1133-1432 1204-1307 1307-1433
1.2
0.5
0.6
0.6
2.8
i 2.8
8.7
4.2
TABLE A-l AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLES expressed as fibres Der milliliter of air (foml)
SAMPLE No
33A-33B 82A 82B 82C
82A-82C 82 153
154
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
19Jun BC 22Jun BC 22Jun BC 22Jun BC 22Jun BC 22Jun BB 25Jun BB
Crusher helper/Mine
Il II Il II Il II Il II
Crusher operator/Mine
Il II
1204-1433 1025-1204 1206-1402 1404-1456 1025-1456 1032-1458 1238-1442
25Jun BC
Crusher helper/Mine
1242-1446
ASBESTOS CONC.
(fpml) Individuai Time-
samle weighted average
REMARKS
6.1
4.6
2.3
4.2
3.5
2.3
2.3
2.9
In control cabin most of
time except for about
10 minutes. Little apparer
dust exposure t
1.5
Sweeping & shovelling in
crusher basement for aboui
li hours. Seemed very
dusty
87
22Jun BD
Bulldozer operator/Mine 1252-1541
0.7
32A
19Jun BE
Tramline helper/Mine
1149-1300
0.2
TABLE A-l
AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- PERSONAL SAMPLE? expressed as fibres Der milliliter of air (fDml)
SAMPLE No
32B 32A-32B
84 85 151 152
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
19Jun BE 19Jun BE 22Jun BE
22Jun BF 25Jun BF 25Jun BE
Tramline helper/Mine
Il II Il II
Tramline operator/Mine
Il II
Tramline helper/Mine
1300-1448 1149-1448 1042-1458
1044-1459 1240-1445 1245-1447
ASBESTOS CONC.
{fpml) Individual Time-
sample weighted average
REMARKS
0 .1
0.7 0.2
0.3
0.2
0.4
Cleaning up aroung buckets
Wore a dust respirator
122
24Jun
E
123A
24Jun BG
123B
24Jun BG
123C
24Jun BG
123A-123C 24Jun BG
Foreman/Tailings area
General laborer/ Tailings area
Il II Il II Il II
0844-1508
0846-1140
1143-1416 1418-1501 0846-1501
1.2
1.2
Mainly at tailings pile
all day.
1
not count able probably>4.1
2.9
In tailings area full time
I I 11
7.4
II ll
Probably
>4.0
II It
TABLE A-2 AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS-STATIONARY SAMPLES expressed as fibres Der milliliter of air (fDml)
SAMPLE No
25A 25B 25C 25A-25C 90A 90B
90C
90A-90C 91 95
127A 127B
DATE
WORKER JOB TITLE/WORKING PLACE SAMPLING PERIOD (24 hour clock)
19 Jun 19Jun 19Jun 19Jun 23Jun 23Jun
23Jun
23Jun 23Jun 23Jun
24,1un 24Jun
milling area next to "C" conveyor near dryer shec
( 1II
IIII
IIII
1326-1346
1346-1426 1426-1526 1326-1526
Behind dryer shed in mil 1 0836-1139
IIII
1141-1320
IIII
1321-1506
IIII
In front of dryer shed
about 40' from location of sample #91(item #215) opposite fire station #2118 Behind dryer shed
II II
0836-1506 0907-1511 0928-1516
1042-1322 1322-1 510
ASBESTOS CONC. (fpml)
Individual Timesample weighted average
12.3
REMARKS
5.7
3.8
5.8
not count able pro bably >3.9
not count
able Probably>7.0
not count able pro bably >6.6
probably > 5.4
not count probably
able
>1.6
Filter was heavily over 1oaded
IIII
IIII '
0.7
0.7
2.0 2.2
TABLE A - 2 AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- STATIONARY SAMPLES expressed as fibres Der milliliter of air (fDml)
11LM
SAMPLE
No
No
19 127A-127B 20 141A 21 141B 22 141C 23 141A-141C
rU\ Ha r1rL
iWmUKmN/Cr.nK Ui aU dD t1 ti x i r / i m n i / T M r mr u nAor uc
Co rAuMIDI IL lTi Kt UIC D1 CL Dl \Tl H\ fHL/
(24 hour clock)
24Jun 25Jun 25Jun 25Jun 25Jun
Behind dryer shed
IIII It II IIII IIII
1042-1510 1158-1350 1352-1531 1532-1545 1158-1545
(AWCURUF<QJ T1nU cU WrnHwWr (fpml)
Individual Timesample weighted average
2.1
2.2
2.3
9.6
2.7
RFMARKS
>24 53
20Jun
Mill Laboratory.
1059-1529
0.9
0.9
>25 71
21 Jun
IIII
1020-1426
1 .0
1 .0
>26 125
24Jun
IIII
0943-1423
0.7
0.7
t
227 59 228 139
229 54
21 Jun 25Jun
20Jun
Behind Bagging machines
Ground floor next to Tec s (Bauer separators)#24D and conveyor 5A,about center of floor opposite fire station # 2123
2nd level.next to Screen 5A
0915-1449 1040-1555
1201-1515
2.4
2.4
0.6
0.6
not count probably
able
>4.0
1 1EM No
230 231
TABLE A-.2 AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS-STATIONARY SAMPLES expressed as fibres Der milliliter of air (foml)
SAMPLE No
64 138
rU\HaIt rCL
iWmUnKiN/Lrrnt UiUoDn T1TiT1ILLr//uwn*niia/iHuIhCU DilunAuruc
CjnAiMDiiILiTtMtru iDCuDrTuAwun (24 hour clock)
21 Jun 25Jun
2nd level,next to Screen 5A
3rd level between Screens 20B-20C
0952-1457 1020-1423
nAJCURLPJQiTOuQv rwOuNmCw
(fpml) Individual Time-
samDle weighted average
not count probably
able
>2.5
1.4
1.4
REMARKS
232
68
233
92
234
93
21 Jun 23Jun 23Jun
Inside baghouse at top of bags
3rd Level. Inside baghouse at top of bags beside open doorway
Inside baghouse at bottom of bags beside open doorway
1040-1507 0920-1455 0928-1458
2.4
2.4 This air was being
circulated into the mill.
0.4
0.4
II
0.6
0.6
II
j
235
66
236
67
237
131
238
56
21 Jun 21 Jun 24Jun 21 Jun
4th level at too of CZ filters and two screens
4th,level at 4D,4C; 6B & 6C Screens
4th level near CT bin
5th level near 24A cyclone screw conveyor
1025-1506 1030-1502 1258-1527 0907-1501
3.2
3.2
1.8
1.8
li
2.8
1.4
1.4 Inspection port on convey
was open
TABLE A- 2 AIRBORNE ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONS- STATIONARY SAMPLES expressed as fibres Der milliliter of air (fDml)
ITEM No
r a u n i r*
a rtn r lc. K1NinO
239
57
240
62
241
63
242
96
243
137
244
140
245
58
246
129
nu nA Ti Ci_
u n D I/iT D
JOB TITLE/WORKING PLACE
SAMPLING PERIOD (24 hour clock)
21 Jun
21 Jun 21 Jun 23Jun 25Jun 25Jun 21 Jun 24Jun
5th level near bucket elevator 2B in ICscreen area
5th level at IB screen and transfer slot
5th level at bottom of 9A cone
0900-1450 0958-1458 1003-1500
5th level near Screens 1C & ID
5th level between Screens IC and ID
5th level near conveyor 12A from cyclone 12A
Eth level at 24B cyclone near stairwell
6th level,at post IA
0943-1457 0947-1518 1144-1501 0915-1451 1117-1520
ASBESTOS C0NC.
(fpml) Individual Time-
sample weighted average
1.4
1.4
not count probably
able
>2.2
2.0
2.0
3.4
3.4
2.3
2.3
3.5
1.4
1.4
4.2
4.2
REMARKS
247
52
248
126
249
130
20Jun
24Jun 24Jun
Ground floor in secre tary's office in mill near foreman's office
Receptionist's office in Administration Bldg. Outdoors n fence ?,dia-j cent. to foreman's offic
1028-1522
1005-1542 1241-1533
8.0
0 .2
2.8
8.0 0.2
ASBESTOS FIBRE CONCENTRATIONS DURING MILL AND MINE OPERATIONSexpressed as fibres Der milliliter of air (fpml)
unoi/cD M U I \ I \ L I \
1AD
uuu
T TxT I r / l . i n D l / T M O
i i l l / rP M \i\iM O
Dl rtPC ru n u L
co na ur irr iu
n m
ir u
nr cr rnamu un
(24 hour clock)
At top of tailings pile 5 min, Sample head pulley area
HAOr nDrtcOTl UAr CaUa IiNi aO.
(fpml) Individua Time-
samle weighted
averaqe
7.3
7.3
1 min. 1 min. 2 min. 4 min. 4 min. 6 min. 6 min. 8 min. 2 min. 10 min.
0 131 53
16 4c 4
33 9.0 8.2 22 7.2
0 131 53
16 4.4 33 9.0 8.2 22 7.2
ITEM N
SAMPLE No
261
16A
262
16B
; 263
16C
264
160
265
16E
266
72
267
73
268
74A
269
75
270
76
271
16F
I
DATE
TABLE A-3 ASBESTOS FIBRE CONCENTRATIONS IN THE TOWNSITE
SAMPLING LOCATION
SAMPLING PERIOD (24 hour clock
ASBESTOS CONC
(fDml)
REMARKS
18Jun
19Jun 20Jun 21Jun 22Jun 22Jun
In kitchen of staff house where we did our microscope work.
IIII
IIII
llll
II II
Various Diaces in townsite, both indoor; and outdoors.
0700-1613
0755-1607 0813-1604 0755-1555 0938-165^ 0955-1758
22Jun < 22Jun 22Jun 22Jun 23Jun
Inside hospital waitinq room
Inside cafereria
Inside the livinq room of 106 ConnelK Street
Inside the livinq room of 706 Cormacks Street
In kitchen of staff house
1018-1700 1032-1832 1047-1847 1125-125 0830-1630
0.02
0.04 0.02 0.04 0.04 0.04
0 0.02 0.0
Stationary sample
IIII
IIII
*
IIII
IIII
Sampler worn continuously day by surveyor while walkinq about town inspection stationary sampl at other sites. Very little win all day
Very little wind all day
Stationary sample. Doors & windows onen all dav
Stationary sample
0 .0
It II
0.01
II ll
TEM
SAMPLE
Nb
No
DATE
2
99A
23Jun
'3
99B
23Jun
74
74B
23Jun
75
74C
76
740
23Jun 23Jun
77
160
24.1 un
TABLE A-3 ASBESTOS FIBRE CONCENTRATIONS IN THE TOWNSITE
SAMPLING LOCATION
SAMPLING PERIOD (24 hour clock
ASBESTOS CONC
(fpmT)-
Rldina bus from town to mill. Sampling started as people started boarding bus and ended as last nerso was leaving
Riding bus from mill to townsite, sampling started as first person boarded bus and ended 1 minute after last person had left bus.
Inside cafereria, persons beaan coming in for dinner at 1715 h . Cafeteria was empty \bv 1915h.
inside cafeteria, one person was removing trays from tables
Inside cafeteria. Mine shift came directly from mine to cafeteria at 2130h. Mill shift came directly from mill to cafeteria at 2319h.
In kitchen of staff house
1431-1456 1459-1519 1719-1028 1932-2129 2129-2359
9754-1705
0.2 0.5 0.0 0.0 0.0
0.01
REMARKS
Two windows across from two rows in
point
were each from
open other, of sampling
Sames as for sample 99A
Doors & windows were open
Stationary sample a
II II
II II