Michigan Network for Children's Environmental Health Blog

A New Study on Breast Cancer Highlights the Need for Chemical Reform

    How many of us have been rocked to the core by that malicious word, “cancer”? If you haven’t been slapped in the face with this fearsome news, then consider yourself a member of the fortunate few. One of every four deaths in the United States is due to cancer.  Down with cancer. Seriously. Its mysteries are maddening. Why do the people we love get cancer? Why do people who lead intentionally careful and healthful lives get cancer? Can we prevent our likelihood of being diagnosed? Is it genetic and inevitable, or environmentally triggered? Can we stop it?! How many family members and friends have asked themselves these questions? Consequently, cancer researchers are asking themselves the same things.  

    A new study of breast cancer done in Ontario, Canada was released this week. It explores increased breast cancer risks in relation to occupational exposures to known carcinogenic chemicals. 

    Next to skin cancer, breast cancer is the most commonly diagnosed cancer in women in the United States. Fewer than half of the cases can be explained by recognized risk factors like family or reproductive history. Breast cancer is likely caused by a combination of environmental, genetic, hormonal, and lifestyle influences. No one fully understands how these factors interplay to increase your risk of a diagnosis. 

    Yet, scientists do have a hunch or two regarding the identification of specific risk factors. In industrialized countries, breast cancer incidence increased dramatically in the second half of the twentieth century as thousands of new chemicals with unknown health effects were introduced. This lead scientists to wonder, is this toxic soup of chemicals that we’re exposed to everyday increasing our risk of getting cancer? What about women exposed to exceptionally high levels of suspected carcinogens by virtue of their occupation? Are these women diagnosed with breast cancer at a higher rate than the general population? This is the set of questions that the scientists in Ontario set out to explore. 

    This study involved the participation of 1005 women with breast cancer and 1147 women without the disease to act as the control group. All women were asked to provide occupational histories in order to determine potential exposures to carcinogens and endocrine disruptors. 

    An endocrine disruptor is a chemical that creates hormone imbalance that results in some cancers, reproductive disorders, immune system dysfunction, birth defects, and neurological effects. Certain occupations require exposures to endocrine-disrupting chemicals on a daily basis.   

    So, what are these high-risk jobs? 

Women in farming showed a 36% increased breast cancer risk.

  •  Several pesticides commonly used in agriculture act as mammary carcinogens and endocrine disrupting chemicals. Women often begin working on the farm at early ages, when they are even more vulnerable to the effects of these toxic pesticides.  

Women in the metal working sector have a 73% increased risk of breast cancer.

  • They work with a variety of potentially hazardous metals and chemicals that metal working processes entail.  

Women in the food canning industry and automotive plastics industry are at a 2-fold increased risk of breast cancer.

  • Women in food canning are exposed to residual toxic pesticides, as well as emissions for the polymer linings of cans. 
  • Women working in the automotive plastics industry are exposed to many plastics that have been found to release carcinogenic chemicals. Cumulative exposures to mixtures of these chemicals are a significant concern.  
  • For women who are pre-menopausal in either industry, their breast cancer risk becomes 5-fold. 

Women in the bar/casino/racetrack sector have a 2-fold increased breast cancer risk. 

  • This may largely be attributable to the greater exposure to second-hand smoke as well as the night work, which has been found to disrupt the endocrine system. 

    For all high-risk job sectors, ten years of work in the industry was estimated to increase breast cancer risk by 42%. How much would you demand to make per hour if you knew that every day you spent at work, you were increasing your likelihood of being diagnosed with breast cancer? 

    To date, no women in Canada from any these high-risk industries have received worker compensation. It’s not like these industries don’t know that the chemicals they’re using have been identified as probable carcinogens. How is this acceptable? These workers are shouldering all of the risks and all of the costs (in the form of medical bills) so that these industries can save a dime by using carcinogenic chemicals as opposed to safer chemical alternatives. It’s not fair; it’s not right. 

    These findings have important implications not only for women workers, but for the general population as well. There are over 80,000 chemicals registered for production today, but fewer than 200 of these chemicals have been tested for human health and safety. These chemicals aren’t being tested because federal regulations, dictated by the Toxic Substances Control Act of 1976, puts the burden of safety determination on the Environmental Protection Agency rather than the chemical manufacturers. The EPA must prove that a chemical presents an “unreasonable risk” for consumers before it can be banned or restricted for use. This has made it really difficult for the EPA to protect us from harmful exposures.   In fact, they can’t do much to protect us until after people begin to sicken or die, and undeniable evidence begins piling up linking these illnesses to a specific chemical exposure. That is too little protection too late for some.  

    As a result, we are exposed every day to the same chemicals that are making women workers in this study sick, albeit at much lower levels. However, some studies are finding that lower exposure to certain endocrine disruptors can actually be more harmful to our bodies than higher exposures. And it’s not like we’re being exposed to one or two carcinogenic chemicals every day, we’re being exposed to hundreds, maybe even thousands every day in the products all around us! That is not what I want for my loved ones or for myself. If safer chemical alternatives exist, we need to begin using them NOW.  

    Please consider taking action today by following this link and telling your federal legislators that we need better protection from toxic chemicals. If we work together, we can protect women in this country from increased breast cancer risk due to toxic chemicals exposures. Follow this link to help us create greater protections.

    For a more detailed summary of this study and its implications, please read this article by the Center for Public Integrity. 


   Brest cancer is one of the most dangerous diseases in women. Most exposed are those that work with chemicals, and a reform in this regard is needed. I know we are all busy, but if we don't do something about this reform, there aren't going to be many mothers to benefit from it.