A woman’s work can play a big role in her chances of developing breast cancer, a recent study conducted in southwestern Ontario’s manufacturing and agricultural belt shows.

Women who worked for a ten-year period in environments where they were exposed to hormone-disrupting chemicals and carcinogens, including in automotive plastics manufacturing, food canning, foundries, bars and casinos and farming, have, on average, a 42 per cent increased chance of developing the disease, researchers say.

Over six years, researchers James Brophy and Margaret Keith compared the occupational histories of 2,152 women in Essex and Kent counties who were diagnosed with breast cancer and those who weren’t. The study was funded by the Canadian Breast Cancer Foundation (CBCF).

“A geographic clustering of excess breast cancer has persisted there over time,” the study says. “In the early 1990s staff at the Windsor Regional Cancer Centre and at the Occupational Health Clinic for Ontario Workers in the Essex-Kent region of Ontario, raised concerns about the numbers of industrial workers developing cancer.”

According to the CBCF, mortality rates for breast cancer have fallen, but incidence rates have remained steady over the past 25 years.

Female workers at the highest risk of developing breast cancer are those in the automotive plastics and food canning industries. They’re about five times (500 per cent) more at risk of breast cancer before menopause.

Other findings include:

  • Women in tooling, foundries and metal-related manufacturing are 1.73 (73 per cent) times more at risk of developing breast cancer.


  • Women working in bars and gambling facilities are 2.28 times (228 per cent) more likely to develop the disease.


  • Women working in farming are 0.36 times (36 per cent) more at risk of developing breast cancer.


“This research reminds us that we need to continue to demand a  precautionary approach to dealing with toxic substances,” Dayna Nadine Scott, director of the National Network on Environments and  Women’s Health, said in a statement. “There is a growing understanding that when it comes to  endocrine disrupting chemicals, even low doses can be dangerous.”

Breast cancer is the most-commonly diagnosed cancer in Canadian women.

“Women are regularly overlooked in occupational health studies and, consequently, there is very little research on the impact of chemical exposures on women in the workplace,” Anne Rochon Ford, executive director of the Canadian Women’s Health Network, said in a statement Monday. “This is a vital contribution to not only the field of women’s health research, but occupational health research as well.”

Read the full study (pdf).