Public Health inspectors at the Northwestern Health Unit address concerns relating to heavy metals. The Northwestern Health Unit region is rich in natural resources that have led to the development of industries such as mining, and pulp and paper. Whether naturally occurring or the result of industrial activities, whether indoor exposure or outdoor exposure, the presence of some heavy metals in our environment can be hazardous to our health.
Arsenic in Soils
Arsenic is a natural occurring heavy metal that is found in rocks.
Is arsenic a health hazard? Long term exposure may increase risk of certain types of cancers and changes to skin pigmentation. Short term exposure to very high levels of arsenic can lead to diarrhea, vomiting, skin rash, and numbness.
Waste products of gold mining (called tailings) may have been deposited in areas where gold mining has occurred and these tailings or 'slimes' can have elevated levels of heavy metals such as arsenic, antimony or cadmium.
People living in the area could be exposed to these metals if they come in contact with the tailings. Exposure generally occurs by ingestion of soil or dust, and the amount of heavy metals taken up in this way is very small. Preschool children may swallow more soil and dust than people in other age groups as they have close contact with soil and dust when they play and tend to put hands and other items in their mouths more often.
Tips to protect your family:
• Don't let children play in tailings areas.
• Don't use tailings sites for biking or other recreational activities.
• Don't use tailings as fill for driveways, gardens, or children's sand
• Cover contaminated soil with a layer of clean topsoil and grass or
• Remove shoes after being outdoors so soil won't be tracked into the
• Wash hands frequently and before eating.
• Brush pets often; especially after they have been exposed to soil
• Do not grow root vegetables in tailings or eat root vegetables
grown in tailings.
Arsenic in Drinking Water
Arsenic can be found in the water from the breakdown of rocks or from deposits of mining tailings. The two most common exposures to arsenic is through food and water. Absorption through the skin is minimal so it is safe to use water containing arsenic for bathing, hand washing, and laundry.
Long term exposure may increase risk of certain types of cancers and changes to skin pigmentation. Short term exposure to very high levels of arsenic can lead to diarrhea, vomiting, skin rash, and numbness.
The Ontario Drinking Water Quality Standard for arsenic in drinking water is 0.025 mg/L.
If you have questions or concerns about health hazards associated with heavy metals or if you would like information on how to test your drinking water, contact your local Northwestern Health Unit office.