Exposure-response analyses for soluble platinum-salt exposed workers and sensitisation: a retrospective cohort study among newly exposed workers using routinely collected surveillance data

Abstract

OBJECTIVES: Soluble platinum salts are well known respiratory sensitising agents leading to work related sensitisation in the work environment. No quantitative exposure response relation has been described for soluble platinum salts. The objective of this study was to explore exposure response relations for soluble platinum salt exposed workers. METHOD: A retrospective cohort study was conducted using routinely collected health surveillance data and soluble platinum exposure data. Workers who newly entered between 1 January 2000 and 31 December 2010 were included and the relation between measured soluble platinum exposure and sensitisation (as determined by skin prick testing) was analysed in more than 1000 refinery workers from 5 refineries from whom a total of more than 1700 personal exposure measurements were available. Exposure response relations were analysed in survival analysis considering changes in exposure over time. Associations were explored for present exposure, cumulative exposure and average exposure. The exposure was lagged by 0.5, 1.0, 1.5, etc. year with a maximum of 5 years. RESULTS: A clear exposure response relation was observed, most strongly for present platinum salt exposure. Exposure lagging showed that exposure preceding sensitisation with maximally 1-2 years was most strongly associated with sensitisation risk. The exposure response relationship was modified by smoking and atopy, but relative risks for smoking and atopy were only modestly elevated. CONCLUSIONS: The precision of estimate of the exposure-response relationship derived from this dataset appears superior to previous epidemiologic studies conducted on platinum salt sensitisation and may as a result have possible utility to occupational exposure standard setting