Canadians are aware of the possibility they are exposed to an assortment of environmental chemicals in their daily lives. We understand that many of these substances are in our bodies, and may be posing some risks to our health. Public health officials and government regulators need better and more direct measurements of exposure to improve decisions for protecting health and preventing disease.
Biomonitoring is the measurement, in people, 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 and fluids such as hair, nails, and breast milk. The measurements are to see how much of a chemical or its elements are present in that person.
Currently, there are limited biomonitoring data for the general Canadian population. In order to fill this data gap and address potential health concerns, Health Canada is collaborating with Statistics Canada in the Canadian Health Measures Survey (CHMS). A biomonitoring component is being added to the CHMS to measure human levels of environmental chemicals in a sample that represents the overall Canadian population.
The CHMS is a national survey to be carried out by Statistics Canada that will collect information from Canadians about their general health. Through personal interviews and the collection of physical measurements, the survey will provide benchmark data on indicators of environmental exposures, chronic diseases, infectious diseases, fitness, and nutritional status, as well as risk factors and protective characteristics related to these areas. The physical measurements will include such factors as height and weight, blood pressure, physical fitness and lung function measures, as well as many measures based on blood and urine samples including environmental chemicals.
The CHMS will be carried out over 24 months beginning in winter 2007, and will involve a sample of 5,000 Canadians, both male and female in the age span of 6-79 years. Approximately 350 respondents will be randomly drawn from each of the 15 randomly selected sites across the country, representing approximately 97% of the population. One thousand respondents, balanced in representation by gender , will be sampled from each of the following age groupings: 6-11, 12-19, 20-39, 40-59 and 60-79 years.
The biomonitoring component of the CHMS will help meet the need for nationally representative data on human levels of environmental chemicals. Blood and urine specimens will be collected in a mobile clinic and analysed for a number of different classes of substances (metals, phthalates, polychlorinated biphenyls (PCBs), brominated flame retardents, organochlorine pesticides, organophosphate insecticide metabolites, phenoxy herbicides, cotinine, perfluorinated compounds and bisphenol-A). There will also be a questionnaire for each respondent to allow for the analysis of risk factors related to exposure to these environmental chemical substances.
One of the most important contributions of the CHMS will be the development of baseline data on the Canadian population that will allow us to assess national distributions of health measures. This first ever national survey will establish current population levels for a broad range of environmental chemicals , provide a baseline for emerging trends and allow comparisons of data with other countries. The results will also allow future research efforts to focus on the link between exposure and health, and provide information to guide action by governments.
For more details about Statistics Canada's Canadian Health Measures Survey, visit http://www.statcan.ca/english/concepts/hs/measures.htm#3