Drinking Water Nitrate and Human Health: An Updated Review.
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.
['Ward|Mary H|MH|', 'Jones|Rena R|RR|0000-0003-1294-1679', 'Brender|Jean D|JD|', 'de Kok|Theo M|TM|', 'Weyer|Peter J|PJ|', 'Nolan|Bernard T|BT|', 'Villanueva|Cristina M|CM|0000-0002-0783-1259', 'van Breda|Simone G|SG|']
D000818:Animals D060766:Drinking Water D004784:Environmental Monitoring D005060:Europe D005260:Female D006801:Humans D008708:Methemoglobinemia D009369:Neoplasms D009436:Neural Tube Defects D009566:Nitrates D009603:Nitroso Compounds D011247:Pregnancy D013959:Thyroid Diseases D014481:United States D014874:Water Pollutants, Chemical
drinking water nitrate methemoglobinemia cancer N-nitroso compounds adverse reproductive outcomes thyroid disease endogenous nitrosation