Most of these children are not living next to Superfund sites, but in our inner cities. Auto exhaust from leaded gasoline and lead paint from older buildings have contaminated the soil in many cases exceeding the EPA threshold value of 400 parts per million. Children are exposed to the lead when they play outside, get dust on their hands, and track soil into their homes.
Unlike homes that fall under the jurisdiction of the Superfund program, there are not any resources available to remove and replace this contaminated soil. Researches at the University of Washington may have identified a cost-effective approach to the problem of high lead in inner city soils. The results of their study are published in the January/February 2003 issue of the Journal of Environmental Quality.
The study, funded by the Water Environment Federation and conducted from 1997-1999, looked at reducing lead contaminated soil from a home garden in Baltimore with different types of municipal biosolids including compost. Biosolids are the nutrient-rich material produced during wastewater treatment. Use of biosolids as a fertilizer for agriculture and for soil reclamation is common. Results from this study suggest biosolids may have another important use in inner cities.
The study added these biosolids and composts to the lead contaminated soil and then used both lab tests and an animal feeding study to evaluate changes in lead levels. The biosolids compost addition to the soil was the most effective of all the biosolids tested with lead reductions ranging from 20-38%. This compost had high iron and manganese concentrations, which were important factors in reducing lead.