Lead Exposure among Canadians: A Pilot Study

Background

Lead can be harmful to the health of people of all ages. Some exposure to lead is unavoidable because lead occurs naturally in the environment. Common sources of exposure to lead include workplace exposures, house dust, consumer products, leaded paint in older buildings, and contaminated food, drinking water and soil.

As we continue to work to reduce our exposure to lead, we need to develop a better understanding of how much lead is stored in our bodies. New science tells us that the lead which is stored in our bones, and released at various times later in our lives, could affect our health.

While there is evidence that our exposure to lead has been decreasing for many years, we do not have a good sense of the total amount of lead stored in a person's body. Lead can be stored in our bones for decades. Approximately 95% of the lead in an adult's body and 70% in a child's body are stored in their bones. The lead stored in our bones can be recycled back and forth from our bones to our blood, leading to elevated blood lead levels from past lead exposure. New technical advances now allow us to measure the amount of lead stored in our bones.

Description of the Study

This study is designed to measure both current and past exposure to lead in a small sample of people from all age groups. Each volunteer will have a bone scan and provide a small blood sample. The bone scan will estimate their past exposure to lead (years to decades ago), while the blood lead results will provide an estimate of current exposure (weeks to months ago). The study will measure lead exposure in 240 males and females between the ages of one and 85. This is a pilot study that will determine whether we are able to conduct such tests in a national survey of Canadians.

For the bone scan, the volunteer sits in a chair and a type of x-ray scan is taken of their leg bones. The bone scan is low risk and painless and takes approximately 30 minutes.

Dr. Fiona McNeil from McMaster University is leading the bone scan work and coordinating the study with scientists at Health Canada. The blood collection and bone scans will take place at St. Joseph's Health Center in Toronto. This center is centrally located within an area of the city with mixed housing, incomes, age groups and cultures and therefore will provide access to a wide range of volunteers from all ages.

Funding Agencies and Research Partners

The study is funded by Health Canada under the Chemicals Management Plan. The Government of Canada has committed $430,000 over three years to support this study. Research partners are from McMaster University and Women's College Hospital.

For more information, see It's Your Health - Effects of Lead on Human Health.