Occupational Asthma in the Aluminum Smelters of Australia and New Zealand: 1991-2006

Objective To examine the incidence of occupational asthma in the seven aluminum smelters of Australia and New Zealand from 1991 to 2006. Methods Incidence and exposure data were collected by survey from the smelters prospectively during the study period. Results The incidence of occupational asthma across all smelters combined was highest in 1992 at 9.46/1,000/year, declining to 0.36/1,000/year in 2006; a 96.2% reduction. The incidence of occupational asthma was correlated with geometric mean total fluoride concentration, measured as personal samples from employees undertaking anode changing (r(s) = 0.497, P < 0.001). Conclusions The control of exposures, respiratory protection and pre-placement medical assessments undertaken during the study period seem to have contributed to the substantial decline in occupational asthma incidence. Am. J. Ind. Med. 54:224-231, 2011. (c) 2010 Wiley-Liss, Inc.