Paul Egan

Detroit Free Press Lansing Bureau

EAST LANSING — The level of lead in the blood of children in Flint likely will rise over the next few months, not because of continued problems with the city's drinking water supply, but because of high levels of lead in the soil — especially in the city's oldest and densest areas — that gets inhaled into their bodies during the summer, according to a Michigan State University researcher.

Richard Sadler, an assistant professor in MSU's department of family medicine, said the yearly seasonal cyclical pattern — which is not unique to Flint, but is common to most big cities — is expected to recur, even as state officials expect the lead levels in Flint's drinking water to diminish. Sadler is coauthor of a study published this week in the International Journal of Environmental Research and Public Health related to lead poisoning in Flint.

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The pattern existed before the Flint water crisis, and is one of the reasons officials in the Department of Health and Human Services say they didn't immediately recognize that something unusual was happening when blood lead levels in Flint children began to spike following the April 2014 switch to the Flint River as the city's drinking water source. In fact, the spike in the summer of 2014 was significantly higher than the spike experienced in Flint in previous recent summers, as Hurley Medical Center pediatrician Dr. Mona Hanna-Attisha eventually demonstrated to resistant state officials, around Oct. 1 of last year.

Just as it confused state officials, the cyclical pattern could lead to public confusion if, as expected, tests show lead levels are rising in Flint children while officials are declaring Flint's water again safe to drink, said Sadler. He worked with Hanna-Attisha on a recent article in the American Journal of Public Health about the spike in blood lead levels caused by Flint's switch to the Flint River as its source of drinking water.

"It's easy to draw that relationship to water being the culprit," when the issue this summer could be lead in the soil, Sadler told the Free Press Wednesday. Officials should find that the increase in blood lead levels this summer is lower than it was in the summers of 2014 and 2015, when residents were drinking Flint River water that was not properly treated with corrosion-control chemicals, he said.

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State health officials are aware of the issue, said Jennifer Eisner, a spokeswoman for DHHS.

"Blood lead levels do not tell us the source of the exposure, which may pose certain challenges in Flint as we work to rebuild trust in the water system," Eisner said in an e-mail to the Free Press. "It’s important that we communicate clearly about all potential lead exposures — including water, soil, and paint — to promote public health statewide."

Sadler's soil-related study found that from 2010 to 2015, lead levels in the blood of Flint children "display consistent peaks in the third quarter of each year," and it demonstrated the problem is worse in the metropolitan center of Flint than the outskirts of the city.

Based in part on other studies, the researchers "infer that resuspension to the air in the form of dust from lead-contaminated soils in Flint appears to be a persistent contribution to lead exposure of Flint children even before the change in the water supply from Lake Huron to the Flint River."

Sadler said Flint and other cities need to examine strategies to remove lead-contaminated soil or reduce its risks though the use of plants that remove lead from soil.

The emphasis on improved nutrition that is a by-product of the Flint water crisis will help minimize the impact of elevated levels of lead from any source, he said.

Contact Paul Egan: 517-372-8660 or pegan@freepress.com. Follow him on Twitter @paulegan4.