By Ben Harder
Lead-contaminated soil in urban parks, gardens, and schoolyards could be made safer by adding composted organic waste, new research suggests. The tactic could reduce the quantity of the toxic metal that moves from the soil to people, especially children, says Sally Brown of the University of Washington in Seattle.
Brown and her colleagues added biosolids–the polite term for byproducts of treated sewage that are blended into fertilizers–to lead-tainted soil from a home garden in Baltimore. Then they fed rats food tainted with various soil-biosolids mixtures. Of nine recipes, eight reduced the amount of lead absorbed into the animals’ bones.