NIOSH
HAZARD REVIEW
Health
Effects of Occupational Exposure
to
Respirable Crystalline Silica
|
Table
23. Lung tumors induced in Fischer 344 rats by a single intratracheal
instillation of quartz
|
||||||
|
Treatment
sample and dose*
|
Sex
|
Observation
time
|
Incidence
of
lung tumors |
Total
number of lung tumors‡ |
Histological
types
|
|
|
Number†
|
%
|
|||||
|
Untreated:
|
||||||
| No dose |
M
|
Died
after 17 months
|
0/32 |
— |
0 |
— |
| No dose |
F
|
Died
after 17 months
|
1/20 |
5 |
1 |
1 adenoma |
|
Quartz
(Min-U-Sil 5):
|
||||||
| 12-mg dose |
M
|
Sacrificed
at 11 months
|
3/18 |
17 |
37
|
6
adenomas, 25 adenocarcinomas, 1 undifferentiated carcinoma, 2 mixed carcinomas, and 3 epidermoid carcinomas |
|
Sacrificed
at 17 months
|
6/19 |
32 |
||||
|
Died
after 17 months
|
12/14 |
86 |
||||
| 12-mg dose |
F
|
Sacrificed
at 11 months
|
8/19 |
42 |
59
|
2 adenomas, 46 adenocarcinomas, 3 undifferentiated carcinomas, 5 mixed carcinomas, and 3 epidermoid carcinomas |
|
Sacrificed
at 17 months
|
10/17 |
59 |
||||
|
Died
after 17 months
|
8/9 |
89 |
||||
| 20-mg dose |
F
|
Died
after 17 months
|
6/8 |
75 |
13
|
1
adenoma, 10 adenocarcinomas, 1 mixed carcinoma, and 1 epidermoid carcinoma |
|
Quartz
(hydrogen fluoride-etched Min-U-Sil 5):
|
||||||
| 12-mg dose |
M
|
Sacrificed
at 11 months
|
2/18 |
11 |
20
|
5
adenomas, 14 adenocarcinomas, and 1 mixed carcinoma |
|
Sacrificed
at 17 months
|
7/19 |
37 |
||||
|
Died
after 17 months
|
7/9 |
78 |
||||
| 12-mg dose |
F
|
Sacrificed
at 11 months
|
7/18 |
39 |
45
|
1
adenoma, 36 adenocarcinomas, 3 mixed carcinomas, and 5 epidermoid carcinomas |
|
Sacrificed
at 17 months
|
13/16 |
81 |
||||
|
Died
after 17 months
|
8/8 |
100 |
||||
| Sources:
Saffiotti et al. [1993; 1996]. *As mg quartz suspended in 0.3 ml saline. †Number of rats with lung tumors per number of rats observed. ‡At all observation times. |
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