Hernán F. Gómez
Between 2006 and 2016, the blood lead levels of children who may have been exposed to corrosive water from the Flint River in Michigan decreased by approximately 73%.
Researchers note that public health efforts to curb blood lead levels appear to have been effective over the past decade.
“During the 11-year timespan assessed, we conclude that there was a 72.9% decline in levels above the CDC reference range of 5 µg/dL, from 11.8% in 2006 to 3.7% during the water switch, to 3.2% in 2016 — the first full year after the switch,” Hernán F. Gómez, MD, associate professor of emergency medicine at the University of Michigan and a pediatric emergency medicine physician at Hurley Medical Center, told Infectious Diseases in Children.
“There is simply no known ‘safe’ blood lead level,” he said. “Although, historically, blood lead levels in Flint and across the nation were significantly higher in the past. Even lifetime pediatric blood lead levels below 5 µg/dL have been shown to decrease IQ and increase risk for behavioral problems. The ultimate goal for Flint and the nation might be reasonably considered to be the complete elimination of lead from any source in the environment.”
When the main water source for residents of Flint switched to the Flint River, blood lead levels increased. Public health efforts to reduce blood lead levels after the switch appear to have been effective, according to researchers from the University of Michigan.
The researchers conducted a retrospective study of children aged 5 years and younger living in Flint, Mich., between 2006 and 2016. They compared blood lead levels (BLLs) before, during and after the children were exposed to corrosive water from the Flint River in 2014-2016. All children were potentially exposed to the contaminated water. The researchers also calculated the percentage of children with BLLs of at least 5 µg/dL and the geometric mean BLLs over the course of the study period.
Of the 15,817 children included in the study, 11.8% had BLLs of 5 µg/dL or greater in 2006. By 2016, this percentage decreased to 3.2% (P < .001). Additionally, a decrease was observed in the geometric mean of BLLs, with 2.33 recorded in 2006 (± 0.04 µg/dL) and 1.15 recorded in 2016 (± 0.02 µg/dL; P < .001); however, the geometric mean increased twice during the study period (2010-2011: 1.75 to 1.87 [±0.03 µg/dL]; 2014-2015: 1.19 to 1.30 [± 0.02 µg/dL]).
According to the researchers, the number of children with BLLs of 5 µg/dL or greater dropped 72.9% between 2006 and 2016. The geometric mean also decreased by 50.6% by 2016.
“The complete replacement of damaged service lines from main water pipes to homes needs to be completed to decrease blood lead levels in this area,” Gómez said. “There has been approximately $250 million of governmental funds dedicated in accomplishing this, and much of this work has been completed.”
“The major source of lead exposure still continues to be children living in older homes with peeling leaded paint, dust and soil contamination,” he added. “The Michigan Department of Health and Human Services has been effective in providing financial aid — $8,000 per household — and other resources for lead mitigation in at-risk homes.” – by Katherine Bortz
Disclosures: The authors report no relevant financial disclosures.