P-345 Biomonitoring for Exposure Assessment to Styrene in the Fibreglass Reinforced Plastic Industry

Introduction Occupational exposure to styrene occurs in the styrene-butadiene rubber, styrene monomer and polymerisation, and reinforced plastics industries. Although the genotoxic potential of styrene is known, very limited and inconclusive information is available regarding its dose-dependent genotoxic effects in humans. The objective of this work was to study occupational exposure to styrene in a multistage approach, in order to integrate the following end-points studied: styrene in workplace air, mandelic and phenylglyoxylic acids (MA+PGA) in urine, Hb adducts, SCE, MN, DNA damage and genotypes of polymorphic genes of some metabolising enzymes. Method Seventy-five workers from a fibreglass-reinforced plastics factory and 77 unexposed controls took part in the study. Results and Discussion The mean air concentration of styrene in the breathing zone of workers was higher than the threshold limit value recommended by the ACGIH, and the BEI adopted by the ACGIH for exposure to styrene was exceeded, indicating that styrene exposure for this group of workers was higher than recommended. The level of Hb adducts and SCE in exposed workers were significantly increased as compared with controls. The DNA damage was higher among styrene-exposed workers than in controls. Concerning the effect of the genetic polymorphisms on the different exposure and effect biomarkers studied, we observed the effect of microsomal epoxide hydrolase activity on Hb adducts of highly exposed individuals and on the levels of SCE of exposed workers. Conclusion The present results suggest the importance of individual susceptibility factors in modulating genotoxicity, although cautious interpretations are required since the size of the study population limits the power of many of the analyses.