Where Risks are Found
In Canada, the production and use of leaded gasoline and lead-based paints has been regulated over the past three decades in an effort to reduce lead exposure. In the early 1980s, Canada began to phase out leaded gasoline for on-road use and lead concentrations in urban air decreased dramatically (Figure 1).1 In 1975, lead concentrations in outdoor air were about 0.55 micrograms per cubic metre (μg/m3); by the 1990s, they were less than 0.05 per μg/m3, a 90% decrease.2
“It is ironic that the removal of lead from gasoline was decreed not to protect the children, but the automobile’s catalytic converter."
—Sergio Piomelli, MD
The lead content of indoor paint in Canada has steadily decreased since the introduction of regulations in 1976, but lead-based paints and lead-soldered pipes often remain in older homes. Over time, the paint in older homes chips and flakes with normal wear-and-tear or when the home is renovated, and lead finds its way into house dust. In older homes or neighbourhoods where lead was used in plumbing or the pipes bringing water into homes, lead can leach into drinking water. Other sources of exposure include food grown in lead-contaminated soil, industrial emissions, and consumer products. In adults, however, lead exposure occurs mainly through occupational activities (e.g. welding) and hobbies (e.g. making stained glass items).
Greatest Risks for Children
Children typically have higher blood lead levels from environmental exposure than adults because of their smaller size and because of the many pathways lead can take to reach them (Figure 2). Young children, especially infants and toddlers who crawl and play on the floor and put their hands and toys in their mouths, can easily ingest lead-contaminated house dust. Children can also be exposed to lead by ingesting soil and playing with lead-containing toys. Although Canada has safety regulations governing lead and other heavy metals in toys, many lead-based products are still imported from countries with less stringent regulations. Recognizing this problem, Health Canada recently reduced the allowable level of lead in consumer products from 600 parts per million (ppm) to 90 ppm.
- 1. Environment Canada. National air pollution surveillance program: Forty years of air quality monitoring and assessment. Ottawa: Environment Canada; 2009. www.ec.gc.ca/Publications/default.asp?lang=En&xml=BABE2D5A-D182-4B9C-85E.... Reproduction is a copy of an official work that is published by the Government of Canada and that the reproduction has not been produced in affiliation with or with the endorsement of the Government of Canada.
- 2. Environment Canada. National air pollution surveillance program: Forty years of air quality monitoring and assessment. Ottawa: Environment Canada; 2009. www.ec.gc.ca/Publications/default.asp?lang=En&xml=BABE2D5A-D182-4B9C-85E....