O4.1 LUNG FUNCTION IN A COHORT OF ASBESTOS EXPOSED WORKERS IN THE POWER INDUSTRY IN VICTORIA

M. Abramson¹, R. Manser², F. Dickson², D. Jolley³, G. Benke¹, M. de Campo², J. Nosworthy², C. Staley², M. Keating⁴, D. Campbell⁵.¹Epidemiology & Preventive Medicine, Monash University, Australia; ²Clinical Epidemiology and Health Service Evaluation Unit, Melbourne Health, Melbourne, Australia; ³School of Health Sciences, Deakin University, Australia; ⁴Regional Respiratory Service, Traralgon, Australia; ⁵Monash Institute of Health Services Research, Melbourne, Victoria, Australia

Background: In 1979, the State Electricity Commission of Victoria established a lung function screening programme for its employees. We wished to establish how lung function amongst participants varied in relation to asbestos exposure and whether this was related to mortality.

Methods: The study population consisted of 3138 former employees who had been medically assessed and had lung function testing between 1979 and 1992. Mortality was ascertained by linkage to the National Death Index and survival analysis performed using Stata software.

Results: At first attendance, 39.6% were current smokers, 32.3% former smokers, and 28.1% had never smoked. Forced expiratory volume in 1 second (FEV₁) was lower among current smokers, and an effect of smoking cessation emerged after the age of 40 years. On average, never smokers had a 7.6% (95% confidence interval 6.3% to 8.9%) greater mean FEV₁% predicted than current smokers, and former smokers had a mean FEV₁% of 5.7% (4.5% to 7.0%) greater than that of current smokers. Asbestos exposure was assessed as negligible (incidental) in 19.8%, environmental (background) in 48.8%, occasional direct handling in 24.5%, and handling in confined spaces for 6.9%. There were significant relationships between FEV₁% predicted at enrolment and both the duration (F = 14.1, p<0.0001) and level (F = 5.77, p = 0.0006) of asbestos exposure. The lowest …