Did the EPA subject poor black families in Baltimore to a potentially dangerous experiment involving sludge? That is the contention of a civil rights group called Project 21 which responded to reports that researchers used federal grant money to test if sludge could reduce child health risks from lead. The sludge, derived from human and industrial waste, was tilled into the yards of nine poor black families after they were told lead had been found and the sludge was safe. Even though sludge can bond with harmful metals, its potential health risks were discounted, and no follow-up medical exams were reported. Project 21 called this “outrageous” and compared it to the infamous Tuskeegee syphilis experiments begun in the 1930’s.