Drinking Water Nitrate and Human Health: An Updated Review

Mary H. Ward*, Rena R. Jones, Jean D. Brender, Theo M. de Kok, Peter J. Weyer, Bernard T. Nolan, Cristina M. Villanueva, Simone G. van Breda

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

361 Citations (Web of Science)

Abstract

Nitrate levels in our water resources have increased in many areas of the world largely due to applications of inorganic fertilizer and animal manure in agricultural areas. The regulatory limit for nitrate in public drinking water supplies was set to protect against infant methemoglobinemia, but other health effects were not considered. Risk of specific cancers and birth defects may be increased when nitrate is ingested under conditions that increase formation of N-nitroso compounds. We previously reviewed epidemiologic studies before 2005 of nitrate intake from drinking water and cancer, adverse reproductive outcomes and other health effects. Since that review, more than 30 epidemiologic studies have evaluated drinking water nitrate and these outcomes. The most common endpoints studied were colorectal cancer, bladder, and breast cancer (three studies each), and thyroid disease (four studies). Considering all studies, the strongest evidence for a relationship between drinking water nitrate ingestion and adverse health outcomes (besides methemoglobinemia) is for colorectal cancer, thyroid disease, and neural tube defects. Many studies observed increased risk with ingestion of water nitrate levels that were below regulatory limits. Future studies of these and other health outcomes should include improved exposure assessment and accurate characterization of individual factors that affect endogenous nitrosation.

Original languageEnglish
Article number1557
Number of pages31
JournalInternational Journal of Environmental Research and Public Health
Volume15
Issue number7
DOIs
Publication statusPublished - 23 Jul 2018

Keywords

  • drinking water
  • nitrate
  • cancer
  • adverse reproductive outcomes
  • methemoglobinemia
  • thyroid disease
  • endogenous nitrosation
  • N-nitroso compounds
  • N-NITROSO COMPOUNDS
  • DISINFECTION BY-PRODUCTS
  • NEURAL-TUBE DEFECTS
  • NITRIC-OXIDE SYNTHASE
  • NITROSATABLE DRUG EXPOSURE
  • CHILDHOOD BRAIN-TUMORS
  • COLORECTAL-CANCER RISK
  • BIRTH-DEFECTS
  • UNITED-STATES
  • ENDOGENOUS FORMATION
  • United States
  • Humans
  • Nitrates/toxicity
  • Thyroid Diseases/chemically induced
  • Neural Tube Defects/chemically induced
  • Female
  • Nitroso Compounds/metabolism
  • Drinking Water
  • Environmental Monitoring
  • Europe
  • Pregnancy
  • Animals
  • Water Pollutants, Chemical/toxicity
  • Methemoglobinemia/chemically induced
  • Neoplasms/chemically induced

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