Nitrate

Nitrate refers to a chemical compound that contains the nitrate ion (NO3-). Nitrate is an important source of nitrogen and is used as a fertilizer in agriculture. Nitrate can also be found naturally in soil, water, seafood, and vegetables. High levels of nitrate in drinking water or food can be harmful to human health, as they can lead to methemoglobinemia (also known as "blue baby syndrome") in infants and increased risk of cancer in adults. Therefore, the Environmental Protection Agency (EPA) has established limits for nitrate levels in drinking water.