No safe amount of lead in drinking water for patients with kidney disease, finds study
The findings suggest that for patients with poor kidney function, there is no safe amount of lead in drinking water.
Even low levels of lead contamination found in the majority of drinking water systems in the United States may have toxic effects for those with chronic kidney disease.
USA: Even low levels of lead in drinking water are detrimental for people with kidney disease, show results from a first nationwide analysis linking EPA (Environment Protection Agency) water supply records to patient data.
According to the study, published in the Journal of American Society of Nephrology (JASN), even EPA permissible lead levels in drinking water is associated with higher erythropoietin stimulating agent (ESA) use and lower hemoglobin levels among people with advanced kidney disease.
Despite advances in reducing the amount of lead in drinking water, low levels of contamination remain widespread throughout the United States. This may be especially dangerous for the 30-40 million Americans living with chronic kidney disease, who have heightened susceptibility to the toxic effects of lead.
To examine the effects of low levels of lead contamination on individuals with advanced kidney disease, investigators analyzed health information for 597,968 patients initiating dialysis in the United States between 2005 and 2017. The team also assessed lead concentrations in community water systems in the 5-year period prior to dialysis initiation, relying on city-level data from the Environmental Protection Agency's Safe Drinking Water Information System.
The investigators focused on the potential effects of lead on levels of hemoglobin, the oxygen-carrying protein in red blood cells known to be affected by lead poisoning.
Individuals living in cities with detectable levels of lead in their community's water had significantly lower hemoglobin concentrations before starting dialysis and during the first month of dialysis therapy. They also were prescribed higher doses of medications to treat anemia, which occurs when red blood cell counts or hemoglobin levels are lower than normal. These associations were observed at lead levels below the Environmental Protection Agency's threshold (0.015 mg/L) that mandates regulatory action.
The findings suggest that for patients with poor kidney function, there is no safe amount of lead in drinking water. "While drinking water may seem uniformly healthy, low levels of lead contamination found in the majority of drinking water systems in the United States may have toxic effects for those with chronic kidney disease," said lead author John Danziger, MD, MPhil, of Beth Israel Deaconess Medical Center. "More rigorous efforts to improve the water system infrastructure may be needed to protect individuals from unrecognized hazard."
Importantly, the study also revealed concerning inequities, with higher water lead levels observed for Black compared with white patients. "Combined with the increased susceptibility to kidney disease among Blacks, this represents an important environmental injustice," said Dr. Danziger.
The study titled, "Associations of Community Water Lead Concentrations with Hemoglobin Concentrations and Erythropoietin-Stimulating Agent Use among Patients with Advanced CKD," is published in the Journal of American Society of Nephrology.