Frequently Asked Questions

Nitrates can be found in drinking water supplies. Their presence in groundwater is generally associated with septic systems, confined animal feeding operations or fertilizer use. These sources of nitrate contamination are more associated with rural settings and are often subjects of drinking water source protection programs.

Nitrates are also present in treated wastewater, and as such can be present in surface water, or in treated wastewater used in groundwater recharge projects. These sources can pose risks to urban drinking water supplies. Nitrates are also used in industry, for example, in the production of fertilizers and explosives.

Nitrite is a chemical similar to nitrate, differing only slightly in its chemical structure. Nitrite comes from the same sources as nitrate. Once consumed, nitrate is converted into nitrite in the body.

Nitrate is a chemical found in most fertilizers, manure and liquid waste discharged from septic tanks. Natural bacteria in soil can convert nitrogen into nitrate. Rain or irrigation water can carry nitrate down through the soil into groundwater. Your drinking water may contain nitrate if your well draws from this groundwater.

Nitrite can interfere with the ability of red blood cells to carry oxygen to the tissues of the body, producing a condition called methemoglobinemia. It is of greatest concern in infants, whose immature stomach environment enables conversion of nitrate to nitrite, which is then absorbed into the blood stream. Clinical effects on infants ingesting nitrite at high levels in foods or from formula made with nitrate-contaminated drinking water are often referred to as the "blue baby syndrome." High nitrate levels may also affect the oxygen-carrying ability of the blood of pregnant women. The groups with the greatest risk of becoming ill through ingesting nitrate are infants under 6 months and pregnant women. In general, the groups with the lowest risk of becoming ill are healthy children and adults.

The best way to prevent “blue baby syndrome” is to avoid giving your baby water that may be contaminated with nitrate and foods that are high in nitrate. Infants less than one-year-old should not be given drinking water with nitrate levels more than 10 ppm. High-nitrate vegetables such as beets, broccoli, carrots, cauliflower, green beans, spinach, and turnips should not be offered until after six months of age.

Low levels of nitrate have been found in breast milk, but the levels are not high enough to cause “blue baby syndrome.”

Nitrate levels in well water can vary throughout the year. If you have a private well and the nitrate level is above five mg/L or if you have not tested your well, you may want to use bottled water for your baby’s foods and drinks. Although boiling water kills bacteria, it will not remove chemicals such as nitrate. In fact, boiling may actually increase the nitrate level.

An infant with moderate to serious “blue baby syndrome” may have a brownish-blue skin tone due to lack of oxygen. This condition may be hard to detect in infants with dark skin.

An infant with mild to moderate “blue baby syndrome” may have symptoms similar to a cold or other infection (fussy, tired, diarrhea or vomiting). While there is a simple blood test to see if an infant has “blue baby syndrome,” doctors may not think to do this test for babies with mild to moderate symptoms.

If your baby has a brownish-blue skin tone, take him/her to a hospital immediately. A medication called “methylene blue” will quickly return the baby’s blood to normal.

Although red blood cells in older children and adults quickly return to normal, some health conditions make people susceptible to health problems from nitrate. They include:

• Individuals who don’t have enough stomach acids.
• Individuals with an inherited lack of the enzyme that converts affected red blood cells back to normal (methemoglobin reductase).

Some studies have found an increased risk of spontaneous abortion or certain birth defects if the mother drank water high in nitrate. Women who are pregnant or trying to become pregnant should not consume water with more than 10 mg/L of nitrate.

If nitrate levels in your water are above 10 mg/L, do not use water to wash, prepare, and cook food for infants below the age of six months. It is advisable to use bottled water or other water low in nitrate.

Yes

Nitrate does not easily enter the body through the skin. Bathing, swimming, and showering with water that has levels of nitrate over 10 mg/L is safe as long as you avoid swallowing the water. Supervise children under six months of age when they are bathing and brushing teeth to ensure they do not swallow the water.

If nitrate levels in your water are above 10 mg/L, do not use water to wash dishes.

Very little water remains on washed surfaces and in laundered fabrics. Because these articles are not placed in the mouth, water with nitrate above 10 mg/L can be safely used for general cleaning and washing of clothing, bedding, and linens.

Nitrate affects young animals the same way as human infants and should not drink water with nitrate more than 10 mg/L