Canadian Environmental Health Atlas

Understanding Our Environment is Key to Promoting Health and Preventing Disease

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Key Points

Chemical Contaminants

  • Drinking water can be an important source of contaminants, including lead and arsenic.
  • Contaminants can enter water as a result of human activities, (e.g. when pollutants are discharged from a factory) or as a result of natural processes (e.g. when chemicals, like arsenic, which are found naturally in rock leach into ground or surface water).
  • Humans are exposed to arsenic primarily through food and drinking water.
  • Long-term, low-level exposure to arsenic is associated with cognitive deficits, preterm birth, cardiovascular disease, and cancer.
  • Arsenic exposure in drinking water occurs around the world, and high concentrations of arsenic in drinking water supplies have been found in a number of Canadian communities.