Selenium is a metal. It's found in natural deposits, usually in materials that also have other elements like sulphide, silver, copper, lead, and nickel. Processed selenium is used to make:
Most rocks and soil contain selenium. It's released into 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 exposure.
Selenium is a nutrient that people need at low levels. But being exposed to high levels can cause health problems.
Eating food with high levels of selenium (like 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 can cause hair loss, brittle nails, and problems with your brain and nerves.
Your water can be tested to see how much selenium is in it. Learn more about
testing your drinking water in Alberta.
The maximum acceptable concentration (MAC) is the highest amount of a metal in drinking water that is safe for a person to drink. If routine testing shows selenium levels over the 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’s
Guidelines for Canadian Drinking Water Quality, the MAC for selenium is 0.05 mg/L (milligrams per litre).
If you are concerned about unsafe levels of selenium in your drinking water:
Any treatment device must be certified to meet these standards:
After you have installed your system, have your treated water tested for selenium to make sure your system is working properly. Monitor and maintain your water treatment equipment according to the manufacturer’s instructions.
If you have any questions about selenium in drinking water, contact Alberta Health Services
Environmental Public Health.
Current as of: April 26, 2022
Author: Environmental Public Health, Alberta Health Services
This material is not a substitute for the advice of a qualified health professional. This material is intended for general information only and is provided on an "as is", "where is" basis. Although reasonable efforts were made to confirm the accuracy of the information, Alberta Health Services does not make any representation or warranty, express, implied or statutory, as to the accuracy, reliability, completeness, applicability or fitness for a particular purpose of such information. Alberta Health Services expressly disclaims all liability for the use of these materials, and for any claims, actions, demands or suits arising from such use.