Main characteristics of the cohort by ILO categories of silicosis: mean (range) values
| 1/0–1/2 | 2/1–2/3 | 3/2+ | |
| Subjects (n) | 154 | 205 | 365 |
| Person-years | 3036.1 | 3900.0 | 6265.9 |
| Calendar year at the first exposure to silica dust (y) | 1931.1 (1926–59) | 1932.1 (1928–60) | 1930.5 (1924–57) |
| Age at the first diagnosis of silicosis (y) | 54.5 (32–74) | 55.1 (29–74) | 57.5 (35–74) |
| Duration of employment in dusty jobs (y) | 24.3 (2–44) | 24.4 (3–46) | 23.7 (3–40) |
| Estimated cumulative exposure to respirable dust (gh/m3) | 176.3 (8–486) | 178.5 (3–445) | 168.7 (9–423) |
| Estimated cumulative exposure to respirable silica (gh/m3) | 7.3 (2–24) | 8.1 (4–28) | 8.6 (7–30) |
| Estimated cumulative exposure to radon daugthers (WLM) | 97.1 (0–270) | 95.0 (0–265) | 89.2 (0–254) |
| Ever smokers (%) | 68.2 | 69.8 | 60.3 |
| Cigarettes/day ⩾15 (% ever smokers) | 25.3 | 25.6 | 19.4 |
| Airflow obstruction (%)1-150 | 39.9 | 45.5 | 51.5 |
↵1-150 Subjects with FEV1/VC <85% of mean predicted (total: 665 subjects with available spirometry).