Table 2.
Number and proportion of workers exposed to McIntyre Powder (MP) in the study cohort. The study cohort was created by linking a database of mining workers’ work history (Mining Master File) to healthcare records in Ontario, Canada. This cohort included 36 826 male miners.
| MP exposure | Self-reports | Historical records |
|---|---|---|
|
|
|
|
| N (%) | N (%) | |
| Ever exposed | 9548 (26) | 13 827 (38) |
| Only before 1956 | 862 (2) | 966 (3) |
| Ever after 1956 | 8686 (24) | 12 861 (35) |
| Only after 1956 | 6459 (18) | 10 187 (28) |
| Never exposed | 27 278 (74) | 22 999 (62) |
| Cumulative duration (years) of MP exposure | ||
| >0–1 | 2296 (6) | 4507 (12) |
| >1–5 | 3833 (10) | 4503 (12) |
| >5–10 | 1655 (4) | 2433 (7) |
| >10 | 1764 (5) | 2384 (6) |