title: Assessment of occupational genotoxic risk in the production of rubber tyres.
abstract: A broad spectrum of substances is used in the rubber industry, many of them being genotoxic and/or carcinogenic. Convincing evidence of an excess of certain forms of cancer among rubber workers has been provided. The objective of this study was to determine the genotoxic effects in a group of individuals engaged in the production of rubber tyres from a Portuguese factory. Peripheral blood samples were collected from 32 exposed workers and 32 controls, and micronucleus (MN) test, sister chromatid exchanges (SCE) and comet assay were performed. Urinary thioethers were measured as a general biomarker of exposure to electrophilic compounds, and genetic polymorphisms in metabolizing enzymes (CYP2E1 Dra I, EPHX1 codons 113 and 139, GSTP1 codon 105, and GSTM1 and GSTT1 deletion polymorphisms) were analysed as susceptibility biomarkers. Excretion of thioethers was found significantly higher in rubber workers. Also, a non-significant increase in MN frequency related to time of exposure and no effect in SCE were observed in the exposed. Comet assay data showed decreased TL values in the exposed population with respect to the control group, this might indicate the induction of crosslinks by the substances present in the workplace environment. Significant increase in MN frequency was obtained for GSTT1 null exposed individuals with respect to positive ones, and interaction with GSTP1 polymorphism was found. Higher levels of cytogenetic test frequencies were observed in epoxide hydrolase expected low activity donors with respect to medium and high activity individuals. No effect of CYP2E1 or GSTM1 variants was obtained in the biomarkers analysed.
authors.affiliation: Toxicology Unit, University of A Coruña, Edificio de Servicios Centrales de Investigación, Campus Elviña s/n, 15071-A Coruña, Spain. blaffon@udc.es
authors.forename: Blanca
authors.initials: B
authors.lastname: Laffon
authors.forename: Joao Paulo
authors.initials: JP
authors.lastname: Teixeira
authors.forename: Susana
authors.initials: S
authors.lastname: Silva
authors.forename: Joana
authors.initials: J
authors.lastname: Roma-Torres
authors.forename: Beatriz
authors.initials: B
authors.lastname: Pérez-Cadahía
authors.forename: Josefina
authors.initials: J
authors.lastname: Méndez
authors.forename: Eduardo
authors.initials: E
authors.lastname: Pásaro
authors.forename: Olga
authors.initials: O
authors.lastname: Mayan
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000652:urine; D006801:Humans; D008297:Male; D015162:Micronucleus Tests; D008875:Middle Aged; D009153:Mutagens / Q000008:administration & dosage / Q000032:analysis*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D011110:Polymorphism, Genetic; D012408:Rubber; D012854:Sister Chromatid Exchange; D013440:Sulfides / Q000652:urine
chemical_list: D015415:Biomarkers; D009153:Mutagens; D013440:Sulfides; D012408:Rubber