asbestosis: (TWA) fibre Duration of Workers who died n=69; exposure. exposure from asbestosis had a Median=39.0 The proportion asbestosis: much greater median (25th-75th of each day n=69; lifetime cumulative percentile spent at each Median=10.4 fibre exposure (39.0 =14.6-283.2) location was (25th-75th fibre/mL-year calculated for percentile compared with 2.4 each job title, 1.2–19.5) fibre/mL-year for and an 8-hour years censored (or alive) TWA exposure workers) and median was estimated length of employment for each job at (10.4 years compared a given time. to 0.8 for The lifetime censored (alive) cumulative workers) fibre exposure Cox models for death for each from asbestosis were worker was statistically significant obtained by (with no lag and summing the lag) for increase cumulative in the hazard of fibre exposure mortality, indicating for each job <1% increase in the that worker hazard of mortality held. with each additional Before 1967 fibre/mL-years of samples exposure (i.e. 1 collected using fibre/mL-years) midget Relative risks (RRs) impinger and showed an increased later samples RR with cumulative using a exposure, which did membrane not become filter. statistically significant Conversion for asbestosis until the
n=69; Median=39.0 (25th-75th percentile =14.6-283.2) (TWA) fibre exposure. The proportion of each day spent at each location was calculated for each job title, and an 8-hour TWA exposure was estimated for each job at a given time. The lifetime cumulative fibre exposure for each worker was obtained by summing the cumulative fibre exposure for each job that worker held. Before 1967 samples collected using midget impinger and later samples using a membrane filter. Conversion Duration of exposure n=69; Median=10.4 (25th-75th percentile 1.2–19.5) years Workers who died from asbestosis had a much greater median lifetime cumulative fibre exposure (39.0 fibre/mL-year compared with 2.4 fibre/mL-year for censored (or alive) workers) and median length of employment (10.4 years compared to 0.8 for censored (alive) workers) Cox models for death from asbestosis were statistically significant (with no lag and lag) for increase in the hazard of mortality, indicating <1% increase in the hazard of mortality with each additional fibre/mL-years of exposure (i.e. 1 fibre/mL-years) Relative risks (RRs) showed an increased RR with cumulative exposure, which did not become statistically significant for asbestosis until the asbestosis: asbestosis: