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Are auto plastics workers more likely to get breast cancer?

Female workers assemble Volkswagen Touran and Tiguan cars at the Volkswagen factory in Wolfsburg, Germany.
Sean Gallup/Getty Images

Yes -- about five times as likely as the general population. The connection has long been suspected but only recently has been confirmed.

A six-year study based in Ontario, Canada, was published in the mid-2000s, with a follow-up published in the fall of 2012. The first was designed to explore a connection between elevated incidences of breast cancer among women who had worked in the agriculture industry, but also determined the connection was even stronger among women who had worked in both agriculture and automotive manufacturing. In other words, working on a farm increases risk; going to an auto plant at some point after the farm work increases risk even more. The study also suggests that early exposure to these conditions (during adolescence or puberty) can predispose a woman to developing breast cancer later in life. The study authors were initially approached by a group of Windsor plant employees in the 1970s, and have completed a number of studies on occupational hazards, each providing more detailed findings than the previous one. A 1994 study showed that female auto workers were not at higher risk for breast cancer, but more recent studies contradict that finding [source: Brophy].

The study compared 299 breast cancer patients to 237 patients with other forms of cancer. In addition to the womens' occupations, it took into consideration other relevant factors such as pregnancy history, hormone therapy, past tobacco use, family medical history and residing in proximity to a farm. Since those factors are all known or believed to affect cancer risk, the study's authors cannot attribute cancer cases directly or solely to the workplace -- they can only note whether the population studied was at higher risk.

The 2012 follow-up study zoomed in on the automotive industry, and determined that female auto plastics workers are five times more likely to develop breast cancer than the general population. They are also more likely to be diagnosed with the disease earlier in life; the average breast cancer patient is in her 60s, but factory and farm workers tend to get breast cancer two or three decades earlier.

There are more than 200 known chemical substances that may trigger the development of breast cancer [source: Brophy]. This list includes pesticides, solvents, hydrocarbons (the same poisonous, polluting toxins that contribute to global warming) and plastics. An auto factory worker might not be too concerned about exposure to pesticides, unlike her agricultural industry counterparts, but the rest of these chemicals are a huge source of concern. Chemicals that are commonly found in occupational (work-related) environments have been shown to cause breast cancer in tests conducted on animals; organic solvents in particular have been shown to cause mammary tumors, and can show up in the breast milk of a subject with steady exposure to the toxin.

For a long time, female factory workers knew their environment was unpleasant and probably sickening, but they didn't know the odors, dust, and toxic fumes could actually be fatal. Women who have spent their adult lives working at plastics plants know not only of the effects on their own health, but that of their coworkers -- some have told reporters that friends on the production lines have suffered high instances of nausea, bladder cancer, infertility and miscarriages. Data for these problems and other related health issues haven't been studied -- though the link between certain conditions and certain toxins is established, it hasn't been tied to the factories -- but such anecdotes illustrate that the female factory workers suspected or knew their work environments were unhealthy and dangerous [source: Morris].

What can be done?

You may have heard the warnings to avoid buying plastic water bottles and food storage containers that contain Bisphenol-A (BPA) -- a plastic hardening compound that helps molded materials retain shape and structure. But it's also dangerous. If you now avoid BPA-laden plastic products because of the chance they might leach toxins into your water, even with occasional use ... well, be grateful if you (or your mother, sister, wife or daughter) aren't inhaling those very same toxins 40 hours a week.

The Canadian study found that anything that interferes with a woman's estrogen levels can increase risk of breast cancer, and exposure to synthetic chemicals (including those that might be found in an auto factory) interferes with the endocrine system. Women who have irregular hormone levels are already at higher risk, which can be minimized somewhat by eating a healthy diet and getting adequate exercise. But the work environments must also be improved. The research is prompting advocates to take a look at standards for factories around the world, to see what can be done to protect women from this dangerous exposure. Improving ventilation around the factories is just one step. Other factories have recently moved machines that create a lot of dust and changed procedures that allowed molten plastic to sit and leach toxins into employees' immediate workspaces.

Nearly 40,000 people died of breast cancer in the United States in 2011 -- although the issue gets a lot of media attention, the occupational hazard connection has so far been underestimated. Of course, these issues aren't exclusive to North America. As study author James Brophy put it, it's "a local study that has far-reaching implications" [source: Quinn]. The phenomenon is beginning to receive more attention -- more links are being established to specific cancer-causing compounds, and other industries, such as textile manufacturing, are being examined. But while factories are taking nominal steps to improve conditions, it's simply not enough. Auto manufacturers, who actually design and build the cars, overwhelmingly say the responsibility falls to their suppliers, who design and manufacture the cars' individual components [source: Morris]. Then, suppliers claim the study data aren't conclusive enough to be worth completely revamping the factory process. Government agencies in the United States and Canada, charged with ensuring the safety of its citizens in the workforce, often pass the buck to sister agencies, claiming their hands are tied until some other committee officially changes the standards.

Despite the risk, and ongoing cancer studies, there have not been any databases that track the occupations of breast cancer patients. Such a program would help communicate the severity of the issue and lead to more research, and perhaps even prompt some prevention programs [source: Brophy].

Author's Note: Are auto plastics workers more likely to get breast cancer?

Researchers and industry experts noted that there have been positive global implications as a result of the women in Windsor who were confident enough to bring attention to their cause. The women who were interviewed, however, said even after getting sick they couldn't quit, because they had no other job prospects. Without the union, it's doubtful the problem would have ever come to light.

And all of this was in Canada, by the way, where we tend to think that things are generally pretty good. Considering all the problems suffered by countless factory workers (both men and women) around the world, it's not a surprise that this study gets little attention.

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  • Breast Cancer Fund. "Vulnerable Populations." (Dec. 3, 2012)
  • Brophy, James, et al. "Occupation and Breast Cancer: A Canadian Case-Control Study." Annals New York Academy of Sciences. 2006. (Dec. 3, 2012)
  • Morris, Jim. "Study spotlights high breast cancer risk for plastics workers." The Center for Public Integrity. Nov. 20, 2012. (Dec. 3, 2012)
  • Quinn, Jennifer. "Union demands protection for workers, after breast cancer linked to auto plastics industry." The Center for Public Integrity. Nov. 20, 2012. (Dec. 3, 2012)