Selenium is a metal. It's found in natural deposits as ores containing other elements (sulphide, silver, copper, lead, and nickel). Processed selenium is used to make:
Most rocks and soil contain selenium. It's released in to air, water, and soil naturally and when it's manufactured. Selenium dust can enter the air when:
Most people are exposed to low levels of selenium every day through food, water, and air. Food is the highest source of selenium that they are exposed to.
Selenium is a nutrient people need at low levels. Being exposed to high levels can cause health problems. Eating food with high levels of selenium (e.g., grains or vegetables grown in soil with high levels of selenium) for a short time can cause nausea, vomiting, and diarrhea. Being exposed to high levels of selenium for a long time (in drinking water) can cause hair loss, brittle nails, and neurological problems.
If routine monitoring shows selenium levels over the maximum acceptable concentration (MAC), your water supplier has to decrease the amount of selenium to a safe level.
If you have a private water source, test your water regularly to make sure it is safe. Make sure to have your water sample tested by an accredited lab.
According to Health Canada, the Canadian drinking water guideline for selenium is 0.05 milligrams per litre (mg/L).
If there is a problem with selenium in any public water supply, customers must be told right away. Another water source must also be supplied to prevent health risks.
If a consumer/well owner is concerned about unsafe levels of selenium in drinking water:
After you have installed your system, have the treated water tested for selenium to make sure your system is working properly. Monitor and maintain your water treatment equipment according to manufacturer instructions.
If you have any questions about selenium in water, call Environmental Public Health.
Current as of: March 13, 2018
Author: Environmental Public Health, Alberta Health Services
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