In addition, all the children's homes were cleaned of lead dust, they were given a mineral supplement, and their blood lead was followed. Detailed testing of their cognitive development, neuropsychological function, and behavior was done at three years of follow up. While the children given succimer had more rapid drops in their blood lead, the differences in tests scores were small, inconsistent, and not statistically significant, the investigators said. The study was large enough to have detected an improved IQ score of less than 3 points, and no such improvement was seen. Side effects were relatively infrequent in both groups, but the children given succimer had an unexpectedly higher rate of injuries, which is so far unexplained.
Children generally have no symptoms below that level.
Succimer remains the recommended therapy for outpatient treatment of children above that level. The children who participated in TLC are being followed for an additional two years to see if some benefit emerges. In an Australian study, children whose blood leads fell faster without treatment when they were two years old had better IQ test scores when they were seven years old, and 7 year old children attend school and read and so can be tested more extensively. Lead poisoning is concentrating now among poor children who are eligible for Medicaid and live in deteriorating, inner city housing.