Styrene associated respiratory outcomes among reinforced plastic industry workers

The study aim was to determine whether styrene exposure was associated with respiratory outcomes in a dose-response manner in the fibreglass reinforcement industry. Workers (n=254) from a fibreglass reinforcement factory were subjected to a standardised interview, spirometry and styrene monitoring. Cumulative exposure was calculated across different jobs and levels of exposure. Logistic regression modelling estimated risk for symptoms, respiratory diseases and lung function change across exposure tertiles. The geometric means of styrene in the General Laminating and Fitting Departments were 48.2 mg/m³ (95% CI 36.3-64.1 mg/m³) and 20.7 mg/m³ (95% CI: 15.6-27.5 mg/m³), respectively. The cumulative exposure odds ratios for chronic cough, phlegm, wheezing and breathlessness for high exposure was 3.1 (95% CI 1.1-8.6), 5.3 (95% CI 1.7-16.6), 3.3 (95% CI 1.2-9.1) and 5.5 (95% CI 1.15-26.4), respectively. The cumulative exposure associated reduction in FEV₁/FVC ratio, percent predicted FEV₁ and FVC was 0.01, 0.04% and 0.05%, respectively. Styrene exposure increases the risk of respiratory symptoms and is associated with reduced lung function.