Women exposed to low levels of common organic solvents at work are 20 per cent more likely to develop breast cancer, a new study suggests.

The study looked at 1,205 women diagnosed with primary breast cancer between 2009 and 2011 and who were on the Western Australian Cancer Registry. They were matched to 1,789 controls from the electoral roll. Exposure to solvents was determined through telephone interviews. About a third of the women were occupationally exposed to solvents.

“The risk of breast cancer was 20 per cent elevated for women exposed to aliphatic solvents or to aromatic hydrocarbons other than benzene. The risks were lower for those exposed to benzene and chlorinated solvents,” the paper, published in the American Journal of Industrial Medicine, noted.

The authors added the risks, which were not statistically significant, “tended to be higher for breast cancer diagnosed before menopause than post-menopause, for those exposed to benzene, aliphatic and other aromatic solvents and chlorinated solvents.” They say the study suggests that there may be an association between occupational exposure to aliphatic and aromatic solvents and the risk of breast cancer at the low levels of exposure experienced by women in their study.

The authors note: “Our findings are consistent with previous reports of an elevated risk of breast cancer associated with occupations where exposure to solvents is likely.”

• DC Glass, J Heyworth, AK Thomson, S Peters, C Saunders and L Fritschi. Occupational exposure to solvents and risk of breast cancer, American Journal of Industrial Medicine, published online ahead of print, 26 May 2015. doi: 10.1002/ajim.22478.