WHAT ARE NITRATES?
Nitrates are a chemical compound - symbol: NO3 - necessary to sustain plant life.
NO3 delivers essential nitrogen to plants. To increase plant size and output, nitrogen fertilizers are used. Nitrates are then often carried by rain, irrigation, and other surface waters through the soil and into ground water through a process known as "leaching." Nitrogen fertilizers are the #1 source of nitrates in drinking water.
The #2 source of nitrates in drinking water is human wastes and animal feces. They can contribute to sickening contamination of both municipal and "bottled" drinking water.
Nitrate levels in drinking water are considered an absolute indicator of overall water quality, along with bacterial infiltration, and presence of chemical toxins.
Elevated nitrate content also suggests the likelihood of other contaminants. These include disease-causing micro-organisms, pesticides, and various inorganic and organic compounds known responsible for serious health problems.
WHAT NITRATE-NITROGEN LEVELS ARE SAFE OR DESIRABLE?
The maximum safe level of nitrate-nitrogen in drinking water is 10 milligrams per liter (commonly written as "mg/l, and synonymous with "parts per million"). The equivalent of 10 milligrams of nitrate-nitrogen, expressed as NO3 nitrate, is 50 mg/l. Levels above this can affect an adult, and could potentially lead to a fatal blood disorder in infants under six months of age.
Both the World Health Organization of the United Nations, and US and state regulations, recommend a MAXIMUM nitrate-nitrogen level no higher than 10 mg/l.
The ideal level in human drinking water for nitrate-nitrogen or nitrate is 0 mg/l.
WHAT ARE THE BIGGEST RISKS?
Methemoglobinemia, commonly known as 'blue baby syndrome,' can occur in infants under six months if nitrate-nitrogen levels are greater than 10 mg/l.
Physiologically, nitrates are reduced to nitrites in the stomach. Nitrite enters the bloodstream and binds to hemoglobin, changing it to methemoglobin. The effect is interference with the blood's ability to carry oxygen to the body tissues.
A baby with methemoglobinemia literally turns blue because his tissues are starved for oxygen as he is slowly being suffocated. Vomiting, diarrhea, and labored breathing are symptomatic of milder presentations, before actual cyanosis (the turning blue-gray of skin, lips, and nails) occurs.
There is a proven correlation between birth defects and high nitrate levels in the carrying mother. Pregnant women must avoid drinking water with nitrate-nitrogen levels greater than 10 mg/l.
Studies suggest a potential link between high nitrates in drinking water and an increased incidence of gastrointestinal cancer. The theory is that the nitrite byproduct combines with amines in the body to form N-nitroso compounds - known for certain to be cancer-causing agents. Despite the data concerning abnormal levels of gastric cancer in regions with high nitrates in the drinking water, the connection is not yet deemed conclusive. However, researchers feel it is prudent to view nitrate-nitrogen levels greater than 10 mg/l as a possible cancer risk factor.
WHAT CAN YOU DO ABOUT IT?
- Know what you are drinking. Municipalities and utilities test their water constantly. To obtain data about your municipal water, call, write, or email the utility. They are legally obligated to make full disclosure. If you drink bottled water, find out what's in it.
- Don't fool yourself. Maybe you are under the impression that "water softeners" purify for nitrates. They don't. You might think that boiling water is a means of destroying nitrates. It isn't - in fact, boiling water actually increases nitrate levels. Under-sink gadgets do not remove nitrates to a significant degree. Reverse osmosis, ion exchange, and distillation can remove nitrates from water, but these devices vary in their effectiveness even when diligently maintained, and can be very costly.
- The only way to guarantee you are drinking low-nitrate water is to get the water from a guaranteed low-nitrate source.
TABLE OF NATURAL MINERAL WATERS' NITRATE LEVELS
DISCLAIMER: Data is taken in good faith from sources believed reliable, including publicly disclosed data from the brand, and various databases including Mineral Waters of the World; "x" means that no data for nitrate level was available from the sources used to collect data for all the other waters - but does not necessarily denote a purposeful witholding of data, or imply that such nitrate levels, if disclosed, would be unfavorable.