Gender and chemicals: A Canadian tale of poisoning women

| November 24, 2011

We inhale, ingest and absorb a litany of synthetic chemicals into our bodies every day. As scientific detection methods improve, we are forced to confront the evidence of these exposures as the results of several biomonitoring studies become available.

Biomonitoring, which involves taking samples from people's blood, hair, or fingernails and subjecting it to close laboratory study to measure precise levels of trace chemicals, is being used in an attempt to match high "body burdens" of certain synthetic chemicals with certain health outcomes. But critics counter that biomonitoring studies are inherently reactive, not proactive, strategies for dealing with the problem of living in a chemical soup. Essentially, they say, it is like using people as instruments to monitor environmental contamination: using children as instruments to test for lead.

Over the same period of time that these exposures have increased, and our body burdens have grown heavier, we have also witnessed a rise in incidence in a number of diseases and disorders including cancer, developmental syndromes, reproductive disorders, and autoimmune diseases. Each of these health problems affects different people differently, and many of them disproportionately affect women. Many in the environmental health movement believe that the rising incidence of many of these disorders and diseases can be tied to our environment and exposures to chemicals. This is in large part due to the emerging body of research that demonstrates that even low levels of exposure to certain chemicals, at certain key times, can have dramatic effects on bodily systems and processes, leading to various adverse health conditions.

Our study

The federal government's Chemicals Management Plan was introduced by the Harper government in 2006 as they trolled for votes with the proclamation that they were about to get "tough on toxics." It is a highly complex policy for the regulation of toxic chemicals, and decision-making under it is highly technical. In our recent report, Sex, Gender & Chemicals: Factoring Women into the Chemicals Management Plan, we examine seven of the government's Screening Level Risk Assessments (SLRAs) in all of their excruciating detail to break through the jargon, the scientific conventions, and the technicalities -- to establish what the government is actually doing when they perform these risk assessments. Specifically, we examine the extent to which the government considers sex and gender in the determination of whether a chemical can be listed as "toxic".

These are critical policy decisions, and the stakes for women are enormous. And yet, the decision-making is obscured. This report is an attempt to bring the debate into the open. We begin now the really tough work of making it mean something to women, and giving them a chance to get into this debate. Our objective in doing this work is to assess and evaluate the current regime for regulating the chemicals released into our everyday environments so as to recommend changes that would create inclusive and comprehensive regulatory processes that ensure the health and safety of everyone.

What we found

We found that there are several places where the government did not consider sex and gender in the risk assessments for common chemicals, and where -- if they had done so -- a chemical may have been listed toxic, but instead remains in circulation.

Take the example of BHA, a common additive used as a preservative in foods, drugs and personal care products. Studies have shown BHA to be carcinogenic and a suspected hormone disruptor. Even though the government had sex-disaggregated data (i.e. they knew what products, and in what volumes, men and women typically use in the course of a day), they still based their calculation on the "mean all-person exposure" estimate. This suggests that the government's overall level of expected exposure is underestimated. Why? Because we know that women use, on average, more personal care products and in greater quantities than men, we know that women's bodies absorb more BHA through the skin, and we know that women experience certain critical "windows of vulnerability" such as puberty, lactation, menstruation, and menopause when they are more sensitive to very small changes in the levels of hormones in the body.

The lack of attention to sex and gender possibly affects future generations as well. For example, consider the case of HBCD, a common flame retardant found in foam used in furniture and window coverings, carpets etc. These substances are highly persistent in the body and in the environment and are known to bio-magnify up the food chain. In fact, the most significant source of exposure for Canadians is through food. Despite this, the government did not consider how HBCDs might affect northern communities reliant on traditional foods, even though fish was singled out as a specific concern. It was also noted that breast-feeding infants would be at significant risk since this contaminant would be passed from mother to child during nursing. At the end of the day, the government based their decision on estimates of exposure through food based on a conventional North American grocery store diet, and therefore ignored the well-being of infants, and future generations, in largely native communities in the north.

On top of deficiencies in the actual assessment process, we also identified weaknesses in the legislation. The Canadian Environmental Protection Act, CEPA, allows for chemicals that have been proven toxic, and listed as such, to be kept on the market for "economic reasons" or to prevent a "stigma" against a particular company's product. In other words, the listing of a substance on the List of Toxic Substances (Schedule 1) -- does not actually trigger any mandatory action on the part of the government. So, on bis-phenol A (BPA) for example, the highest profile "win" for environmentalists on toxics in many years, the government declared it to be "toxic", phased in a ban on baby bottles that contain it, but did nothing to prevent people from being exposed to it from other sources -- such as the from lining of tin cans or debit receipts.

It is not just women's health we are concerned about. The report attempts to further the ultimate goal of the government in establishing the Chemicals Management Plan -- reductions in exposures to harmful substances for everyone. But a truly precautionary chemicals policy is one that pays careful attention to sex and gender. This is because chemicals affect different bodies differently. To illustrate, emerging research indicates that there are several chemicals for which low levels of exposure to male embryos in utero gives rise to specific health difficulties, including reproductive disorders, later in life. In order to understand the increasing incidence of reproductive problems and infertility, then, we need to pay attention to sex and gender in our toxicity studies. Similarly, breast cancer prevention advocates would point to the fact that lab studies rarely employ female mice and rats in their carcinogenicity tests as a critical shortcoming of our efforts to understand the role of synthetic hormones in causing breast cancer.

Gender is important in another respect. What we have found over the past several years of studying these issues is that, by and large, women bear the burden of this regulatory failure. Women do the bulk of the household shopping and make most of the everyday consumption choices for families. There is good evidence emerging that women are engaging in what Norah MacKenrick calls "precautionary consumption" -- green shopping practices undertaken to try to compensate for the fact that the regulatory system is broken. While we understand why women engage in these practices, our research causes us to question their effectiveness. The most privileged of us might be able to buy the right sofas, carpets and electronics to protect our families against the risks posed by flame retardants in the context of our own homes, none of us will choose these for our children's schools, public libraries, hospitals, or transit systems. We have limited individual control over these exposures. Further, we need a system that protects everyone -- not just those with the resources, time, education and knowledge to be "savvy" green shoppers.

What we recommend

We need to be engaged with policy on toxics. We need open and transparent decision-making that identifies clear trade-offs between risks and benefits (and to whom each will fall). Industry interests have dominated the agenda, and have driven the government's assessment processes. We need to make real demands on the government to consider sex and gender in the policy process, and to implement a truly precautionary policy stance that puts people first. We also need to understand that while our individual consumption choices are important, our control over our exposures is constrained by legislation, institutions, politics and power. These, as Michael Maniates has argued, are remade through collective citizen action, not individual consumer behaviour. It's time to get tough on toxics, for real.

Dayna Nadine Scott is the director of the National Network on Environments and Women's Health.