Nitrate-Nitrite Quandary

Molecules that contain a nitrogen atom bonded to two oxygen atoms are called nitrites and ones with three oxygen atoms bonded to the nitrogen are called nitrates.

Sodium nitrite and sodium nitrate have long been used to flavor, color, and preserve cured meats, a result being to virtually eliminate the risk of botulism poisoning in the United States. Nitrates are essential to plant and animal life and are extensively used to manufacture fertilizer and explosives.

Unfortunately, ingestion of too much nitrate, especially in infants, causes damage to their hemoglobin's ability to carry oxygen. A more serious health hazard is that the human body can covert nitrate to nitrite, and then the nitrites combine with other nitrogen compounds called amines to form cancer-causing agents. Another worry is that excessive use of nitrate fertilizers over the years may, like fresh aerosol sprays, partially destroy the earth's protective ozone layer.

Not yet known is the seriousness of the problem of cancer from nitrates and nitrites. Nor is the seriousness of the ozone depletion problem known.

Because nitrates and nitrites make positive contributions to human life and also can be terribly damaging, federal agencies charged with fostering food production and safeguarding health are in a quandary about how far regulations on nitrate and nitrite content should go.

Very likely, the United States is moving toward a total ban in the use of nitrites for food coloring and preservation. The nitrate issue is more complex because we take nitrate into our bodies from many sources. The main source is in the vegetables we eat. Drinking water is another source; up to ten parts per million is considered safe for consumption by infants.

Nitrate in drinking water is thought to come mostly from heavy use of nitrate fertilizers on farmland or where wells are contaminated by runoff waters from cattle feedlots and animal pastures where nitrate is contained in effluent from the animals. Nitrate in water can come from completely natural sources also. For example, in the Fairbanks area, certain wells are found to have high nitrate content. These wells are in the low hills north of Fairbanks where there is no indication of a fertilizer or animal source. Since the wells with high nitrate tend to lie just at or below the 750-foot contour level on southerly slopes, ground temperature may be a factor. Very likely the nitrate derives from the decay of peat moss just above freezing temperature.