Feature Article February 5, 2003
LAND O' LAKES NewsWeb HomeNitrates in drinking waterby Wilma KennyNitrate is a naturally occurring chemical, much of which comes from decomposition of plants and animal/human waste. People also add nitrate to the environment in the form of fertilizers. Elevated nitrate levels in groundwater are often caused by run-off from septic systems or barnyards. Nitrate contamination of a well is often regarded as a first sign of deteriorating groundwater quality. Methemoglobinemia [also known as "Blue Baby Syndrome"] is a health problem associated with nitrate ingestion. In young children, nitrate is converted to nitrite, then absorbed into the bloodstream, where it interferes with the ability of the blood to carry oxygen. Onset can be rapid, and demands immediate medical attention. Older adults may also be adversely affected by nitrates. The recommended limit for nitrate in drinking water is 10 ml/L. This limit is set by Health Canada, the U.S. Environmental Protection Agency, and the World Health Organization. Water with nitrate levels at or near this level should never be used for children under six months. Pregnant women, nursing mothers, or people with reduced stomach acidity are also advised to avoid nitrate-contaminated water. Do not boil water to get rid of nitrates, as boiling concentrates the nitrate more. Free nitrate testing is available at local Health Units, but results will take several weeks. Faster replies can be obtained from private labs for a small fee. For further information about nitrates, contact the Health Unit.
