Scientists have known for decades that drinking water contaminated by fertilizer nitrates can pose a threat to infants by undermining the ability of their blood to carry oxygen. The condition, known as ‘blue baby syndrome,” led federal regulators to impose an environmental standard of no more than 10 parts per million, or ppm, for nitrates in public water supplies. Recently, though, some evidence suggests that long-term ingestion of drinking water with nitrates at just half that federal limit can prove dangerous to children and adults alike, potentially raising the risk of bladder, thyroid, kidney, ovarian and colon cancers.
A new report from the Environmental Working Group, a research and advocacy organization, indicates that more than 1,700 water districts across the U.S. recorded nitrate levels that averaged 5 ppm or more in 2014–2015. The vast majority — 1,683 of the water districts — were rural systems serving no more than 25,000 people and generally located in farming areas where fertilizer and manure in cropland runoff can seep into the public water supply. Included in those rural districts were 118 systems that matched or exceed the U.S. Environmental Protection Agency’s limit of 10 ppm. The report by EWG, which […]