Exposure to lead is determined by blood tests, and measured in micrograms of lead per deciliter of blood. The Centers for Disease Control and Prevention has set a “level of concern” at 10 micrograms per deciliter. Even at low levels, lead poisoning in children can cause IQ deficiencies, reading and learning disabilities, impaired hearing, reduced attention spans, hyperactivity and other behavior problems. A study by Mary Jean Brown, assistant professor of maternal and child health at the Harvard School Public Health, examined 137 addresses in two adjacent urban areas in the northeastern U.S. where children with high blood lead levels (25 micrograms per deciliter of blood) were identified between 1992 and 1993. The two areas were similar in many aspects but differed regarding provisions for the enforcement of lead-related housing policies; one employed strict enforcement and the other did not. The study suggests that lead abatement is associated with a savings per building, over a 10-year span, of more than $45,000. The findings were published in the November/December 2002 issue of Medical Decision Making. The study was funded in part by John and Virginia Taplin and the Maternal and Child Health Bureau.