More than 5.6 million Americans exposed to high concentrations of nitrates in drinking water

Analysis shows that Hispanic communities are disproportionately exposed

According to a new study, more than 5.6 million Americans are potentially exposed to nitrate levels in drinking water that can cause health problems. In this first badysis of this type, researchers found that water systems with higher nitrate levels also tended to serve communities with more and more Hispanic residents. The findings add to the growing concern about the quality of drinking water in the United States and the disproportionate impact of contamination on vulnerable populations.

"Since the lead crisis in Flint, Michigan, there has been a lot of pressure to document other types of disparities in the quality of drinking water in the United States and to understand the factors that affect them. motivate, "says Laurel Schaider, lead author of the study and environmental specialist. chemist at the Silent Spring Institute. "Because at the end of the day, everyone should have access to clean and safe drinking water, regardless of race or place of residence."

Nitrate is a drinking water contaminant that can come from multiple sources, including fertilizers, wastewater treatment systems, and animal manure. Using information obtained from government agencies and online databases, Schaider and colleagues at the Silent Spring Institute and the Environmental Working Group (EWG) compiled nitrate data for 39,466 water distribution systems serving more than 70% of the American population. The team noted for each water supply system the number of people served by the system and the source of drinking water, whether it comes from groundwater or surface water.

Reporting in the newspaper Environmental healthresearchers found that 1,647 public water systems supplying drinking water to more than 5.6 million Americans had an average nitrate concentration equal to or greater than 5 mg / L (or 5 parts per million (ppm)), the highest proportion of water rich in nitrate systems found in the West and the Midwest.

Currently, the EPA standard for drinking water relative to nitrates is 10 ppm. This level is set to protect infants from a potentially life-threatening illness called "blue baby syndrome", a decrease in the blood's ability to carry oxygen in the body. However, recent studies suggest that exposure at concentrations as low as 5 ppm is also badociated with several cancers and birth defects, which increases the possibility that the water quality standard of the lungs may increase. EPA does not protect enough health.

"Nitrates are also a good indicator of the presence of other contaminants in drinking water," said Schaider. In previous research, Schaider and his colleagues discovered pharmaceuticals and consumer products in drinking water with nitrate levels greater than 1 ppm. Water with higher nitrate concentrations tended to have higher concentrations of these contaminants.

To determine whether low-income or color communities are exposed to higher levels of nitrates in their drinking water, researchers have linked data on the water supply system to information provided by the US Census Bureau on race, ethnicity, household urban areas. They also examined agricultural data, including the percentage of land used for cultivation and the number of animals, as agriculture is a major source of nitrate pollution.

The badysis showed that the higher the proportion of Hispanic residents, the more likely that their drinking water will contain nitrate levels above 5 ppm. The researchers observed the same relationship even after taking into account the use of agricultural land. In other words, although a large percentage of agricultural workers are Hispanic, living in a region with many farms is not the only underlying factor, suggesting that other factors are also contributing factors. to increase exposures.

At this point, it's hard to know what these influences are, Schaider says. Living near other sources of nitrate pollution, such as a sewage treatment plant, is a potential risk factor, she said. Being served by a small water supply system is another, as small water supply systems usually lack the resources to combat contamination. Language barriers can also make it difficult for communities to seek support to improve the quality of their drinking water.

"If so, then it suggests that government programs could help improve the quality of water in minority communities," said Schaider.