bioremediation composting

This is the kind of thing that over the years has made me such a passionate advocate of composting:
http://epa.gov/osw/conserve/rrr/composting/pubs/bioremed.pdf
"... investigated the use of compost to bioremediate soils contaminated by lead
and other heavy metals at both urban and rural
sites. In Bowie, Maryland, for example, he found a
high percentage of lead in soils adjacent to houses
painted with lead-based paint. To determine the
effectiveness of compost in reducing the bioavailablility of the lead in these soils, Chaney fed both
the contaminated soils and contaminated soils
mixed with compost to laboratory rats. While both
compost and soil bound the lead, thereby reducing
its bioavailability, the compost-treated soil was
more effective than untreated soil. In fact, the rats
exhibited no toxic effects from the lead-contaminated soil mixed with compost, while rats fed the
untreated soil exhibited some toxic effects..."