A study published recently in the journal Environmental Science and Technology confirmed that contaminated soil is to blame for increased blood lead levels in children during the summer. The research, which tracked more than 367,000 children in Detroit over a nine-year period, found that seasonal fluctuations in blood lead levels found in children are the result of resuspended dust contaminated with lead.
Lead exposure is considered to be the number one environmental threat to American children. Research has shown that even at levels that do not cause immediate symptoms, lead poisoning can cause permanent brain damage.
While children’s exposure to lead has declined since lead was eliminated from gas, paint, water pipes and the solder on canned goods, scientists have noted a seasonal rise in blood-lead levels among urban kids, reports Brita Belli for E Magazine. The purpose of the recent study was to figure out why children displayed higher blood lead levels in the summer versus winter.
“What we have done is demonstrate that increased blood lead levels in the summer are connected to increased amounts of soil and dust contaminated with lead,” said lead researcher Shawn P. McElmurry, assistant professor of civil and environmental engineering in Wayne State University. “This soil is resuspended into the air to a greater extent during the summer than during the winter, hence showing decreased lead levels in children during the winter months.”
Kids in urban areas often play near roadways, vacant lots, and buildings where soil is more likely to be contaminated by past deposits of gasoline, outdated plumbing and toxic pesticides, putting them at greater risk of exposure. In the summer, soil is dry, making it easier for contaminated particles to be kicked up as dust by the wind. Then, increased humidity levels help to suspend these particles in the air, where they are inhaled.
“In Detroit, a city with some of the highest blood-lead levels in kids, a study in the American Journal of Public Health found a direct correlation between lead levels in kids and poor academic performance, writes Belli. “Children with 2-5 micrograms per deciliter of lead in their blood had a 33 percent greater likelihood of poor academic performance. Those lead levels are equal or below those set by the Centers for Disease Control and Prevention.”
The discovery that soil (aka dirt and dust) is poisoning our kids is bad news, especially in urban areas that have elected to turn vacant lots and road-facing lawns into community gardens. ”In places where the soil is heavily contaminated, urban food production may raise as many public health concerns as it solves,” said Samantha Langley-Turbaugh, a soil scientist at the University of Southern Maine in Portland, told LiveScience.com. Unfortunately, few studies have examined the quantity of lead-contaminated produce a person would need to eat in order to raise levels of lead in the blood.