Secondary |
Lin |
1996 |
Canada |
LMW |
Wood dust or bark |
Western red cedar |
Western red cedar workers (Includes cohort reported by Chan-Yeung, 1987 and Cote, 1990) |
Occupational asthma |
Removal from exposure (FU mean: 5.3 yrs - unexposed workers; FU mean: 6.9 yrs - exposed workers; FU mean: 4.0 yrs - controls) |
201 of 280 eligible subjects (Participation rate: 72%) |
Subjects who continued to be exposed (n=158) had a more rapid decline in FEV1 (-26 ml/yr, p=0.09) than controls (saw mill workers, n=399). Subjects who were removed from exposure after diagnosis (n=122) showed a similar rate of decline in FEV1 (-3 ml/yr, p=0.86) compared to controls. |