Decreased lung function associated with occupational exposure to epichlorohydrin and the modification effects of glutathione s-transferase polymorphisms.

Epichlorohydrin (1-chloro-2,3,-epoxypropane; ECH) is a strong irritant of the eyes, respiratory tract, and skin. Because the toxic effect of various chemicals can be modified by metabolic traits, in this study, we also investigated the influence of the glutathione S-transferase (GSTM1) and (GSTT1) genes on the toxic effect of ECH. In the GSTM1 null genotype workers, there is a dose-response of lung function tests (FEV1, FEV1/FVC, MMEF) for ECH exposure, but not in the GSTM1 non-null genotype workers. The ECH exposure was found to be significantly associated with a decreased FEV1 value (P = 0.09) and a decreased MMEF value (P = 0.053) after adjusting for other factors. The GSTM1 null genotype was found to be significantly associated with a decreased FEV1 value (P = 0.038), decreased FEV1/FVC value (P = 0.056), and decreased MMEF value (P = 0.012) after adjusting for other factors. This study indicates that obstructive lung abnormalities and small airway lung damage are associated with ECH exposure, and ECH workers with GSTM1 null-type are also associated with increased respiratory damage.

Pulmonary function abnormality and respiratory tract irritation symptoms in epichlorohydrin-exposed workers in Taiwan.

BACKGROUND: Epichlorohydrin (ECH) is a strong irritant of the eyes, respiratory tract, and skin. The aims of this study were to examine the dose-response relationship between observed abnormal pulmonary function tests and respiratory tract irritation symptoms among epichlorohydrin-exposed workers in Taiwan. METHODS: A total of 167 workers were randomly selected from a resin synthesis factory. Sixty-six air samples were taken to determine ECH concentration in the workplace. Demographic data, work history, smoking status, and respiratory tract irritation symptoms were gathered by a standard self-administered questionnaire. Pulmonary function tests were also performed. RESULTS: There were 13 of 41 (31.7%) abnormal mean mid-expiratory flow (MMEF) among the high-ECH-exposed workers, 11 of 38 (29%) among the low-ECH-exposed workers, and 4 of 59 (6.8%) among non-ECH-exposed workers. There was a significant linear trend between ECH exposure and the prevalence of small airway abnormalities (P = 0.007) after adjusting for other factors. There was also a significant dose-response relationship of respiratory tract irritation symptoms (cough, phlegm, chest tightness, and dyspnea) among the ECH-exposed workers. CONCLUSIONS: This study suggests that obstructive lung abnormalities and small airway lung damage are associated with ECH exposure. The study also suggests that exposure to very low concentrations (<0.2 ppm) causes significant higher prevalence of respiratory tract irritation symptoms. Causal inferences from the findings cannot be made from this cross-sectional study and further longitudinal studies are needed to better clarify the nature of the observed associations.

Effects on sister chromatid exchange frequency of polymorphisms in DNA repair gene XRCC1 in smokers.

The association between metabolic polymorphisms and cigarette smoking-induced cancers has been documented. However, the role of DNA repair polymorphism in carcinogenesis is less clear. To investigate if the polymorphisms of metabolic traits and DNA repair modulate smoking-related DNA damage, we used sister chromatid exchange (SCE) as a marker of genetic damage to explore the relationship of microsomal epoxide hydrolase (mEH), glutathione S-transferase M1 (GSTM1), and X-ray cross-complementing group 1 (XRCC1) and cigarette smoking-induced SCE. Sixty-one workers without significant exposure to mutagens were recruited. Questionnaires were completed to obtain detailed occupational, smoking, and medical histories. SCE frequency in peripheral lymphocytes was determined using a standard cytogenetic assay and GSTM1, mEH (exons 3 and 4), XRCC1 (codon 399) genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR/RFLP). Smokers had higher SCE frequency than non-smokers (8.4 versus 7.1, P<0.05). Among workers who had smoked equal to or greater than 10 cigarettes each day, those with XRCC1 Arg/Gln+Gln/Gln had higher SCE frequency than those with XRCC1 Arg/Arg after adjusting for potential confounders (9.0 versus 7.9, P<0.05). The interaction of XRCC1 and cigarettes smoked per day on SCE frequency was also observed (P=0.02). There was no significant interaction between cigarettes smoked per day with GSTM1 and mEH on SCE frequency. Our results support previous epidemiological studies that XRCC1 may play a role in cigarette smoking-induced lung cancer.