New data from the Canadian Health Measures Survey (CHMS) for the reference period from 2022 to 2024 were recently released, including data on more than 100 environmental chemicals measured in Canadians.
These data are used in Health Canada’s Canadian Biomonitoring Dashboard, which shows levels of environmental chemicals in the Canadian population.
Let’s have a look at the findings in the dashboard for three priority chemicals—cadmium, lead and mercury—all of which have declined by over 30% in Canadians since the start of the CHMS.
Lead
The decline in levels of lead since the 1970s is largely attributable to the elimination of its use in gasoline for on-road vehicles as well as some consumer products and building materials. Today, Canadians are mainly exposed to lead through food and drinking water, though some are exposed through cigarette smoke.
From 2007 to 2024, average lead levels were down by 45%. The average levels of lead in the Canadian population aged 6 to 79 years was 0.74 micrograms per decilitre (µg/dL) of blood from 2023 to 2024 compared with 1.3 µg/dL of blood from 2007 to 2009. The decline appears to be continuing with the 2023-to-2024 levels down by almost one-tenth (-9.8%) from when it was last measured from 2018 to 2019.
Mercury
Mercury enters the environment through natural sources like erosion and volcanic activity, as well as from industrial activities. It stays in the environment for a long time and is present in all parts of the world, even in the Arctic.
The general population in Canada is mainly exposed to methylmercury (a form of mercury that can accumulate in living organisms) by eating fish. As fish is part of a healthy diet, Health Canada provides guidance on fish consumption to help ensure methylmercury exposure remains low.
From 2023 to 2024, the average total blood mercury level was 0.46 µg/L for those aged 6 to 79 years, down 36% from 0.72 µg/L from 2007 to 2009. People aged 20 to 79 saw a similar decline in levels of methylmercury from 0.69 µg/L from 2012 to 2013 to 0.44 µg/L from 2023 to 2024. Adults had higher average levels of mercury in their blood than children and adolescents.
Cadmium
Cadmium mostly enters the environment from industrial activities (like metal production and fuel combustion), does not break down and can build up over time. The general population is mainly exposed to cadmium through either food (among non-smokers) or tobacco products (among smokers).
From 2023 to 2024, the average blood cadmium level was 0.24 µg/L for those aged 6 to 79, down 31% from 0.35 µg/L from 2007 to 2009. It has seen a more gradual decline in recent years than lead or mercury, from 0.25 µg/L from 2018 to 2019 to 0.24 µg/L from 2023 to 2024 (-4.0%).
Cadmium levels were more than six times higher for smokers compared with non-smokers from 2023 to 2024. The decline in cadmium levels from 2007 to 2024 among smokers (-34%) was more than twice that of the rate among observed in the population that does not currently smoke (-16%).
To learn more
For more information about the biomonitoring of these three metals, visit these Health Canada web pages:
Note to readers
The Canadian Health Measures Survey (CHMS) is the only ongoing nationally representative source of direct health measures in Canada. It provides detailed insight into the health conditions and behaviours of the Canadian population and is designed to inform the prevention, diagnosis and treatment of illnesses, as well as to promote health and wellness.
The CHMS collects biomonitoring data to better understand exposures to environmental chemicals and changes in these exposures over time in the Canadian population. The CHMS is led by Statistics Canada in partnership with Health Canada and the Public Health Agency of Canada.
Data for Cycle 7 of the CHMS were collected from November 2022 to December 2024, though blood and urine samples were only collected from January 2023 to December 2024. The target population included individuals aged 1 to 79 years living in the Canadian provinces. The observed population excluded individuals living in the three territories, people living on reserves and other Indigenous settlements in the provinces, the institutionalized population, and residents of certain remote regions. Altogether, these exclusions represent approximately 3% of the target population.
Contact information
For more information, contact the Statistical Information Service (toll-free 1-800-263-1136; 514-283-8300; infostats@statcan.gc.ca) or Media Relations (statcan.mediahotline-ligneinfomedias.statcan@statcan.gc.ca).