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. Children who live in communities that strictly enforce lead-poisoning-prevention regulations are less likely to suffer the effects of lead poisoning than children in communities where the rules are not enforced, according to a Harvard study. The study spanned five years, 1993-1998, and examined 137 households in adjacent areas in two northeastern U.S. states where a child with lead poisoning lived in 1992. Enforcement differed significantly in the two communities. In one area, property owners who failed to reduce lead hazards and notify tenants about lead inspection results were subject to civil and criminal charges. In the second neighborhood, lead inspections were limited and rarely resulted in control of lead poisoning dangers, and civil or criminal charges were not filed against property owners for failure to notify tenants of lead hazards.