Lead (Pb) is a heavy metal that occurs naturally in the Earth's crust. In addition, lead has many industrial uses. The extensive use of lead has resulted in its widespread presence in the environment.
The production of batteries used mainly in the automotive industry is the single largest global market for refined lead, since lead was phased out in gasoline additives, household paints, and solder in food cans.
Lead is also used in the manufacture of many materials such as pipes, circuit boards, sheeting, electrical components and polyvinyl chloride, radiation shielding, ammunition, paint primers for iron and steel, wheel balance weights, weights for analytical instruments, and yacht keels.
Canadians are exposed to low levels of lead through food, drinking water, air, household dust, soil, and various products. Before leaded gasoline was phased out in Canada, lead in the air was the predominant source of exposure for Canadians. Today, the primary source of exposure to lead for Canadians is from food and drinking water. Several factors can affect your exposure level, such as whether your home has a lead service connection, or your plumbing has components or solder containing lead, or your food has been grown in soil containing lead. Occupational exposure to lead, as well as living in the vicinity of a point source, can also contribute to overall exposure to lead.
Infants and young children are more likely to ingest lead because of their natural habit of putting objects into their mouths and because they have different behaviours than adults (such as crawling, greater frequency of hand-to-mouth contact, etc.). Ingestion of non-food items containing lead (such as dust, lead-based paint, soil and products), along with food and drinking water, are the greatest sources of exposure to lead in the environment for infants and children.
Lead can be harmful to people of all ages. Recent scientific studies on lead show that adverse health effects are occurring at lower levels of exposure to lead than previously thought. At low levels of exposure, the main health effect observed is in the nervous system. Specifically, exposure to lead may have subtle effects on the intellectual development and behaviour of infants and children. Infants and children are particularly vulnerable to the harmful effects of lead because they are undergoing a period of rapid development. Furthermore, their growing bodies absorb lead more easily and excrete lead less efficiently than adults. In adults, the strongest scientific evidence to date suggests low levels of lead exposure may cause a small increase in blood pressure.
Health Canada has conducted an assessment of the most current science on lead and consolidated the information in a Final Human Health State of the Science Report on Lead.
Globally, governments have undertaken a broad spectrum of initiatives, both domestically and through international collaboration, to reduce human and ecological exposure to lead and other hazardous chemicals. While progress varies from country to country, it is generally acknowledged that collectively, these measures are contributing to improvement in human health.
The amount of lead in the environment increased significantly in the 1920s and stayed at higher levels until the 1970s, when lead was gradually phased out of gasoline and household paint, and lead solder in food cans ceased to be used. Through risk management actions already in place, the levels of lead in the blood of Canadians have declined by over 70% since the 1970s.
The Government of Canada has implemented a wide range of regulatory and non-regulatory initiatives in collaboration with provincial and territorial governments, industry and other stakeholders, as part of a comprehensive lead risk management strategy. Actions taken have affected, and continue to influence, the mining, fuel and transport sectors, consumer products, water and soil quality, and food, to name a few.Given that recent scientific studies on lead show that adverse health effects are occurring at lower levels of exposure to lead than previously thought, the proposed risk management objective for lead is to provide continuing support for existing risk management actions under the Risk Management Strategy for Lead and pursue additional management measures to reduce exposure to lead, and hence associated risks, to the greatest extent practicable.
Being informed is the best protection. Find out more about lead and reducing your exposure by reading the It's Your Health - Effects of Lead on Human Health fact sheet.