A new study shows that some occupations, such as those that expose workers to carcinogens and endocrine disrupters, raise risks for breast cancer. Jobs sectors that showed an increased risk included agriculture, bar/gambling, automotive plastics manufacturing, food canning, and metal-working.

The study, published in the journal Environmental Health, looked at 1006 breast cancer cases in Southern Ontario, Canada. The patients took surveys and were interviewed, providing researchers with their occupational histories. The jobs were then coded for their likelihood of exposure to carcinogens and endocrine disruptors.

The researchers found that women in jobs with high potential exposures to carcinogens and endocrine disruptors had an “elevated” risk for breast cancer. Premenopausal breast cancer risk was found to be highest for the automotive platics and food canning professions.

“Our results highlight the importance of occupational studies in identifying and quantifying environmental risk factors and illustrates the value of taking detailed occupational histories of cancer patients,” said James Brophy, lead author of the study. “Mounting evidence suggests that we need to re-evaluate occupational exposure limits in regulatory protection.”

The study also found that women with lower socioeconomic status’ also had an elevated risk of breast cancer. The researchers speculated that this increased risk may stem from higher exposures to endocrine-disrupting chemicals in low-income jobs in the manufacturing and agricultural industries.