Sodium nitrate should not be confused with sodium nitrite, which is also a common food additive and preservative used, for example, in deli meats. Less common applications include as an oxidizer in fireworks, replacing potassium nitrate commonly found in black powder, and as a component in instant cold packs.
https://en.wikipedia.org/wiki/Sodium_nitrate
High levels of nitrate in the body can cause methemoglobinemia, also known as blue baby syndrome. This sickness is extremely rare, but it is important to be aware of the risks. The most common symptom of methemoglobinemia is a bluish color of the skin, headache, dizziness, weakness or trouble breathing.
http://www.groundwater.org/get-informed/groundwater/nitrates.html
An open source photometer as been developed for this method to accurately detect nitrate in water, soils, forage, etc. According to Hackaday this device can be built for US$65 to use this method to quantify nitrate accurately. Free nitrate ions in solution can be detected by a nitrate ion selective electrode.
https://en.wikipedia.org/wiki/Nitrate
Nitrates are chemical compounds that can be found in drinking water supplies. While harmless in small amounts, high levels of nitrates can affect humans and animals negatively. This is especially true for infants and pregnant women. Nitrates infiltrate drinking water through several sources.
http://www.groundwater.org/get-informed/groundwater/nitrates.html
Nitrate in drinking water starts affecting the health of the general populace at levels in the range of 100 to 200 mg/l nitrate-N, but the effect on any given person depends on many factors, including other sources of nitrate and nitrite in the diet.
http://psep.cce.cornell.edu/facts-slides-self/facts/nit-heef-grw85.aspx
Methemoglobinemia is the most significant health problem associated with nitrate in drinking water. Blood contains an iron-based compound called hemoglobin, which carries oxygen. When nitrite is present, hemoglobin can be converted to methemoglobin, which cannot carry oxygen.
http://psep.cce.cornell.edu/facts-slides-self/facts/nit-heef-grw85.aspx
The construction and location of drinking water wells often have the most to do with the amount of nitrates in your drinking water. New wells should be located uphill and at least 100 feet away from potential contaminant sources like feedlots, septic systems, barnyards and chemical storage facilities.
http://www.groundwater.org/get-informed/groundwater/nitrates.html
Nitrate is composed of one atom of nitrogen (N) and three atoms of oxygen (O); the chemical symbol for nitrate is NO3. Nitrite (NO2) can be formed from nitrate by a chemical process called reduction. Nitrate does not normally cause health problems unless it is reduced to nitrite. Nitrate in drinking water is measured either in terms of the amount of nitrogen present or in terms of both nitrogen and oxygen. The federal standard for nitrate in drinking water is 10 milligrams per liter (10 mg/l) nitrate-N, or 45 mg/l nitrate-NO3. when the oxygen is measured as well as the nitrogen.
http://psep.cce.cornell.edu/facts-slides-self/facts/nit-heef-grw85.aspx
Nitrites are produced by a number of species of nitrifying bacteria, and the nitrate compounds for gunpowder (see this topic for more) were historically produced, in the absence of mineral nitrate sources, by means of various fermentation processes using urine and dung. Nitrates are found in man-made fertilizers.
https://en.wikipedia.org/wiki/Nitrate
Dietary nitrate can be found in cured meats, various leafy vegetables, and drinking water; nitrite consumption is primarily determined by the amount of processed meats eaten, and the concentration of nitrates in these meats. Nitrite and water are converted in the body to nitric oxide, which could reduce hypertension.
https://en.wikipedia.org/wiki/Nitrate
where can nitrates be found
Nitrates can be found in drinking water supplies.