Canadians are exposed to a variety of chemicals, both naturally-occurring and human-made, throughout their daily lives. We understand that many of these chemicals are in our bodies, and there are questions about the potential for these chemicals to affect our health. Public health officials and government regulators need better and more direct measurements of the exposure of Canadians to these chemicals in order to improve decisions for protecting health and preventing disease.
Biomonitoring is a key tool used as an indicator and quantitative measure of exposure to chemicals in the environment. Human biomonitoring data contribute to our understanding of exposure and provide information to inform the management of the health risks posed by chemicals.
Biomonitoring is the measurement of a chemical, the products it makes after it has broken down, or the products that might result from interactions in the body. These measurements are usually taken in blood and urine and sometimes in other tissues such as hair, saliva and breast milk.
It is difficult to predict levels of chemicals in people using estimates or measurements of chemicals in air, soil, water, food or commercial products. These predictions require us to make assumptions about personal habits and lifestyles, and make assumptions about how the chemicals are absorbed, distributed, used and eliminated from the body. Biomonitoring provides a more direct estimate of chemical exposure and will help to make sound decisions about the health of Canadians.
Large national or regional-scale biomonitoring surveys can help measure our exposure to chemicals, and help us determine if the exposure is changing over time. An example of such a study is the Canadian Health Measures Survey (CHMS), a national survey being led by Statistics Canada, in partnership with Health Canada and the Public Health Agency of Canada. This survey collects information from Canadians about their general health and includes measurements of chemicals in blood and urine samples.
National studies such as the CHMS provide us with baseline levels of chemicals in Canadians and the basis for future monitoring and research activities.
Human biomonitoring data can be used by governments, researchers and health practitioners in a wide variety of ways:
Human biomonitoring is an important tool; however, there are certain limitations in its use. Although technological advances in laboratory methods have improved our ability to measure chemicals and generate biomonitoring data, our ability to interpret biomonitoring results in relation to the risks the levels pose to health is limited. More work needs to be done to assess the sources of exposure and to evaluate the toxicological and health impacts of exposure to chemicals. For many chemicals, further research is needed to understand what health effects may be related to exposure at different levels.
The Government of Canada plays a key role in protecting Canadians from exposure to potentially harmful chemicals through legislation that governs chemical substances in food, water, drugs, pesticides, and consumer products. This legislation includes the Canadian Environmental Protection Act, 1999, the Pest Control Products Act, the Food and Drugs Act, and the Canada Consumer Product Safety Act.
In addition to biomonitoring surveys and studies, Health Canada conducts science and research that support biomonitoring. This work includes the development of new chemical measurements and analytical methodologies, the development of tools to better interpret biomonitoring results, and the investigation of possible adverse health effects that may result from exposure to chemicals. These efforts will lead to more effective use of biomonitoring data in managing the health risks of chemicals and enhance our ability to interpret and communicate biomonitoring study results. In addition, Health Canada has a leadership role in producing and disseminating national biomonitoring data, identifying new priority chemicals for future studies, contributing to international monitoring efforts, and facilitating cooperation with other organizations with an interest in biomonitoring.