FRIDAY, March 1 (HealthDay News) -- Children's levels of exposure to lead-contaminated airborne dust while outdoors explain the seasonal changes that occur in their blood lead levels, a new study reports.

Past research has shown that blood lead levels among children living in U.S. cities can rise by more than 10 percent in July, August and September, and then decrease during winter and spring.

This nine-year study of more than 367,000 children in Detroit concluded that wind, humidity and other weather-related factors increase the amount of lead-contaminated dust in the air during those three months, when children are also more likely to be outside.

The lead in the dust was deposited in the soil years ago, said the authors of the study published online recently in the journal Environmental Science & Technology.

Average blood lead levels in the United States and worldwide have declined following the elimination of lead from gasoline, paint, water pipes and solder used to seal canned goods, according to a news release from the American Chemical Society.

The study findings have implications for government efforts to reduce children's exposure to lead, which can cause serious health problems, the researchers said.

"Our findings suggest that the federal government's continued emphasis on lead-based paint may be out of step (logically) with the evidence presented, and an improvement in child health is likely achievable by focusing on the [lead in airborne dust] as a source of exposure," wrote Shawn McElmurry, of Wayne State University in Detroit, and colleagues.

"Given that current education has been found to be ineffective in reducing children's exposure to [lead], we recommend that attention be focused on primary prevention of lead-contaminated soils," the study authors concluded.

More information

The U.S. Environmental Protection Agency has more about lead.

SOURCE: American Chemical Society, news release, Feb. 25, 2013

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