Where It Comes From
Fertilizer/manure runoff and wastewater that convert nitrate to nitrite; food preservatives (e.g., sodium nitrite in processed meats) [1][2].
How You Are Exposed
Drinking contaminated private well or small-system water; eating cured meats; certain workplaces (food processing, wastewater) [1][2].
Why It Matters
Can cause methemoglobinemia (“blue baby syndrome”), headaches, dizziness, and in infants, serious illness; nitrite can form N‑nitroso compounds linked to cancer risk [1][3][4].
Who Is at Risk
Infants under 6 months; pregnant people; those with specific enzyme deficiencies or on medicines that increase methemoglobin; people relying on private wells; high consumers of processed meats [1][2][3].
How to Lower Your Exposure
Test private wells regularly; use certified treatment (reverse osmosis or ion exchange) or safe water for infant formula; follow water advisories; limit processed meats; use workplace protection as directed [2][3][1].
References
- [1]ATSDR. ToxFAQs for Nitrates and Nitrites. https://www.atsdr.cdc.gov/toxfaqs/tfacts204.pdf
- [2]U.S. EPA. Basic Information about Nitrate and Nitrite in Drinking Water. https://www.epa.gov/ground-water-and-drinking-water/basic-information-about-nitrate-and-nitrite-drinking-water
- [3]WHO. Nitrate and Nitrite in Drinking-water: Background document for development of WHO Guidelines. https://www.who.int/publications/i/item/WHO-SDE-WSH-03.04-56
- [4]IARC Monographs Vol. 94: Ingested Nitrate and Nitrite. https://publications.iarc.fr/11547/monographs-94-ingested-nitrate-and-nitrite-and-cyanobacterial-peptide-toxins-2010