Pulmonary function and oxidative stress in workers exposed to styrene in plastic factory

Abstract

Styrene is a volatile organic compound used in factories for synthesis of plastic products. The pneumotoxicity of styrene in experimental animals is known. The aim of the present study was to study the effect of styrene on lung function and oxidative stress in occupationally exposed workers in plastic factory. Thirty-four male workers, between 18 and 40 years of age, exposed to styrene for atleast 8 hours a day for more than a year were studied, while 30 age- and sex-matched healthy subjects not exposed to styrene served as controls. Assessment of lung functions showed a statistically significant reduction ( p < 0.05) in most of the lung volumes, capacities (FVC, FEV1, VC, ERV, IRV, and IC) and flow rates (PEFR, MEF75%, and MVV) in the study group (workers) as compared to controls. Malondialdehyde (MDA) was observed to be significantly high ( p < 0.05) while ferric-reducing ability of plasma (FRAP) was significantly low ( p < 0.05) in styrene-exposed subjects. Reduced glutathione (GSH) level was significantly depleted in exposed subjects as compared to control group. The mean value of serum cytochrome c in styrene-exposed subjects was found to be 1.1 ng/ml (0.89–1.89) while in control its levels were under detection limit (0.05 ng/ml). It shows that styrene inhalation by workers leads to increased level of oxidative stress, which is supposed to be the cause of lung damage.