Nitrate can be removed from water only with specific filters. Boiling contaminated water can actually concentrate nitrate. The nitrogen-containing compounds collectively termed nitrates come from a variety of sources. Nitrate enters the soil from human or animal waste and nitrogen-containing fertilizers. Seepage into groundwater causes contamination.
Nitrate levels are high in food grown in soil, such as fruits and vegetables.
Nitrates are also found in processed meats. When consumed, nitrates are converted to potentially harmful by-products in the body. The process is complex and depends on many factors, such as stomach acidity. Vitamin C can prevent this conversion. Maternal exposure to nitrate from drinking water and diet and risk for neural tube defects.