Human Biomonitoring of Environmental Chemicals
In everyday life, people in Canada are exposed to a variety of naturally occurring and human-made chemicals. Human biomonitoring provides a direct measure of these chemicals in people. Biomonitoring data contribute to our understanding of chemical exposures and to the development of policies to protect the health of people in Canada.
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What is Human Biomonitoring?
Chemicals are everywhere – in air, soil, water, products and food – and can enter the body through ingestion, inhalation, and skin contact. The Government of Canada uses a variety of methods, tools, and models to determine human exposure to chemicals (both natural and human-made) and the potential effects on human health. Human exposure to chemicals can be estimated indirectly by measuring chemicals in the environment, food, water or products, or measured directly in people using biomonitoring (see Figure 1).
Human biomonitoring is the measurement of how much of a chemical, or the substance(s) it makes when it breaks down, is present in a person. This measurement (called the level or concentration) is usually taken from blood or urine samples, and sometimes from other tissues and fluids, such as hair, nails and human milk.
Human Biomonitoring in Canada
Health Canada, in collaboration with other departments and institutes, conducts a number of human biomonitoring activities in general and targeted populations within Canada.
Canadian Health Measures Survey (CHMS)
The CHMS is a national repeated cross-sectional survey led by Statistics Canada in partnership with Health Canada and the Public Health Agency of Canada. The CHMS collects information from people living in Canada about their general health, and includes measurements of chemicals in blood and urine samples. These data are available through an interactive online tool called the Canadian Biomonitoring Dashboard, and in reports and fact sheets. The nationally representative information collected by the CHMS establishes baseline levels of chemicals in the Canadian population, helps assess changes in exposures over time, and informs research and regulatory activities.
Maternal-Infant Research on Environmental Chemicals (MIREC) Research Platform
The MIREC Study recruited a pan-Canadian longitudinal cohort of approximately 2,000 participants in their first trimester of pregnancy. The MIREC Research Platform encompasses this original study, as well as the MIREC Biobank and follow-up studies. Biological samples, questionnaire data and direct health measures are collected at various time points from the parents and children in the cohort. The MIREC Research Platform is a critical resource for examining chemical exposures and related health effects at multiple life stages, including fetal development, infancy, childhood, adolescence, pregnancy and perimenopause.
Northern Contaminants Program (NCP)
The NCP is a multidisciplinary initiative, funded by the Government of Canada, addressing health, science, and communication issues related to contaminants in Canada’s Arctic. The NCP is led by Crown-Indigenous Relations and Northern Affairs Canada, in partnership with Health Canada, Environment and Climate Change Canada, Fisheries and Oceans Canada, and Indigenous organizations such as Inuit Tapiritt Kanatami, Inuit Circumpolar Council, Dene Nation and Council of Yukon First Nations. Biological samples (blood, milk, urine and hair) are collected from adults, pregnant people and children to determine exposure to chemicals found in traditional / country foods, and to provide information to Northerners to make informed decisions about their food use.
Using Human Biomonitoring Data
Human biomonitoring data are used by governments, researchers and health practitioners in a wide variety of ways:
- Establish baseline concentrations of chemicals in Canadian populations and track trends in concentrations over time.
- Compare levels of chemicals among different populations (including sub-populations within Canada or populations of other countries).
- Provide information for setting priorities and taking action to reduce exposure to environmental chemicals and protect the health of people in Canada.
- Inform chemical risk assessments by providing information on measured levels in Canadian populations, which is important for estimating exposures to chemicals from various sources.
- Assess the effectiveness of risk management actions intended to reduce exposures and health risks from specific chemicals.
- Support research on the potential links between exposure to certain chemicals and specific health effects.
- Contribute to international chemical monitoring under programs such as the Arctic Monitoring and Assessment Programme (AMAP) under the Arctic Council, and the Stockholm Convention on Persistent Organic Pollutants.
Limitations
Human biomonitoring is a valuable tool to measure exposure to chemicals; however, its limitations must be understood in order to use the data appropriately.
Human biomonitoring measures how much of a chemical is present in a person at a point in time, but it cannot say what health effects, if any, may result from that exposure. The presence of a chemical in a person’s body does not necessarily mean that it will affect a person’s health. Factors such as the amount to which a person is exposed, route of exposure, the duration and timing of exposure, and the toxicity of the chemical are important considerations to determine whether adverse health effects will occur.
The absence of a chemical does not necessarily mean a person has not been exposed. Existing technology may not be capable of measuring a very small amount, or the exposure may have occurred at an earlier time, allowing for the chemical to be eliminated from the person’s body before measurement took place.
Human biomonitoring does not indicate the source or route of chemical exposures. The amount of chemical measured represents the total amount that has entered the body through any or all routes of exposure (such as ingestion, inhalation, or skin contact) and from any or all sources (such as, air, water, soil, food and consumer products). The presence of a chemical may be the result of exposure to a single source or multiple sources. In most cases, biomonitoring cannot distinguish between natural and human-made sources.
Government of Canada’s Management of Chemicals
The Government of Canada plays a key role in protecting people living in Canada from exposure to chemicals that may be of concern. A risk-based approach to chemicals management is taken, using risk management strategies designed to reduce chemical exposures. In 2006, the Government of Canada launched the Chemicals Management Plan to further enhance the protection of people living in Canada and their environment from exposure to chemicals. National, longitudinal and targeted human biomonitoring activities are key components that inform decisions made under this plan. Human biomonitoring information assists with the evaluation of risk management measures and the development of policies that aim to reduce chemical exposures and protect the health of people living in Canada.
For more information
Additional information about how the Government of Canada manages chemicals can be found on the Chemicals Substances section of canada.ca.
Additional information about the CHMS can be found on the Statistics Canada website.
Additional information about the MIREC Research Platform can be found on the MIREC Canada website.
Additional information about the Arctic Monitoring and Assessment Programme can be found on the AMAP website.
Human biomonitoring has also been conducted through the First Nations Biomonitoring Initiative (FNBI).
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