RT Journal Article SR Electronic T1 The Upper Midwest Health Study: gliomas and occupational exposure to chlorinated solvents JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 73 OP 80 DO 10.1136/oemed-2011-100588 VO 70 IS 2 A1 Avima M Ruder A1 James H Yiin A1 Martha A Waters A1 Tania Carreón A1 Misty J Hein A1 Mary A Butler A1 Geoffrey M Calvert A1 Karen E Davis-King A1 Paul A Schulte A1 Jack S Mandel A1 Roscoe F Morton A1 Douglas J Reding A1 Kenneth D Rosenman A1 Patricia A Stewart YR 2013 UL http://oem.bmj.com/content/70/2/73.abstract AB Objectives Occupational exposure to chlorinated aliphatic solvents has been associated with an increased cancer risk, including brain cancer. However, many of these solvents remain in active, large-volume use. We evaluated glioma risk from non-farm occupational exposure (ever/never and estimated cumulative exposure) to any of the six chlorinated solvents—carbon tetrachloride, chloroform, methylene chloride, trichloroethylene, tetrachloroethylene or 1,1,1-trichloroethane—among 798 cases and 1175 population-based controls, aged 18–80 years and non-metropolitan residents of Iowa, Michigan, Minnesota and Wisconsin. Methods Solvent use was estimated based on occupation, industry and era, using a bibliographic database of published exposure levels and exposure determinants. Unconditional logistic regression was used to calculate ORs adjusted for frequency matching variables age group and sex, and age and education. Additional analyses were limited to 904 participants who donated blood specimens (excluding controls reporting a previous diagnosis of cancer) genotyped for glutathione-S-transferases GSTP1, GSTM3 and GSTT1. Individuals with functional GST genes might convert chlorinated solvents crossing the blood–brain barrier into cytotoxic metabolites. Results Both estimated cumulative exposure (ppm-years) and ever exposure to chlorinated solvents were associated with decreased glioma risk and were statistically significant overall and for women. In analyses comparing participants with a high probability of exposure with the unexposed, no associations were statistically significant. Solvent-exposed participants with functional GST genes were not at increased risk of glioma. Conclusions We observed no associations of glioma risk and chlorinated solvent exposure. Large pooled studies are needed to explore the interaction of genetic pathways and environmental and occupational exposures in glioma aetiology.