BLOOMINGTON, Ind. -- Children in homes relying on private well water are 25 percent more likely to have elevated blood lead levels than children in homes served by community water, according to a new study by Indiana University researchers.
The study, published July 6 in Proceedings of the National Academy of Sciences, is the first that specifically looks at lead exposure in children who rely on private wells.
"Recent crises like the one in Flint, Michigan, have put a spotlight on lead in city drinking water," said Jackie MacDonald Gibson, author of the study and chair of the Department of Environmental and Occupational Health at the IU School of Public Health-Bloomington. "But children getting their water from private wells have been overlooked as a population at risk of lead exposure from their drinking water."
In the United States, 42.5 million people -- 13 percent of the population -- depend on unregulated private wells for their water. Although regulations on lead in gasoline, paint and food cans enacted in the 1970s and through the 1990s reduced exposure, lead exposure among children remains an issue.
Lead is a neurotoxin known to contribute to irreversible cognitive and developmental impairment in exposed children. And lead exposure before age 7 has been associated with decreased IQ, poor performance in school and increased risks of behavioral problems.
Gibson and researchers from other univerisites used a curated dataset of blood lead records from 59,483 North Carolina children matched with household water source information. They found that children relying on private wells had blood lead concentrations that were 20 percent higher, on average, than children with community water service.
The study also found that blood lead concentrations and risks of elevated blood lead were higher among children in older or lower-valued homes, in areas with a higher percentage of non-Hispanic Black residents, and in neighborhoods excluded from nearby municipal services.
"This issue can have long-term effects on some of our most vulnerable populations," Gibson said. "Risks are especially high for children in low-income households and in African American neighborhoods that remain excluded from access to nearby municipal water service -- a legacy of discriminatory zoning practices. This unfortunate legacy contributes to persistent intergenerational poverty through its impacts on children's cognitive development."
Gibson said the increased exposure is likely a result of corrosion of household plumbing and well components. Corrosion control is regulated in community water systems through the Safe Drinking Water Act; it is not required for private wells.
Gibson said that households with private wells must be stewards of their own water quality, monitoring for lead on their own and, when necessary, installing and managing their own corrosion-control systems or replacing lead-containing well components and plumbing. But she said that is seldom done because of a lack of knowledge about how to test water properly, the cost of testing and the potential cost of fixing problems that may arise.
"Since households with private wells are not required to monitor their water quality -- and rarely report doing so on a voluntary basis -- they are generally unaware of these risks," Gibson said. "In turn, children consume water with higher lead in homes using private wells than in homes with community-supplied water containing corrosion inhibitors."
The researchers think more education and support, including financial and technical support to help households and communities solve problems of lead in water and lead screening questionnaires for pediatricians asking about their patients’ water sources, are needed to combat this issue.
"This study highlights the need for an overhaul of the Safe Drinking Water Act to provide support for households relying on private wells," Gibson said. "That includes financial support, and education and support on proper testing. No level of lead exposure is safe. This is an issue that must continue to be addressed.
Michael Fisher and Allison Clonch from University of North Carolina at Chapel Hill, John M. MacDonald of the University of Pennsylvania, and Phillip J. Cook of Duke University also contributed to the study.
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