The Center for Disease Control and Prevention decided against lowering its blood lead “level of concern” standard, which is currently set at ³ 10 mg/dL. This blood lead “level of concern” is the blood lead level (BLL) at which the CDC recommends intervention actions be taken. However, several recent studies have shown a lead related decline in children’s IQ below this “level of concern.” One recent longitudinal study concluded that children loose an average of 7.4 IQ points as BLL rise from 1 to 10 mg/dL. In addition, a large meta-analysis has found lead related intellectual deficits among children with BLL < 7.5 mg/dL. Finally, the CDC’s own Work Group to the Advisory Committee on Childhood Lead Poisoning Prevention concluded in 2004 that the weight of the scientific evidence favored a causal association between blood lead levels below the CDC’s blood lead “level of concern” standard and the loss of IQ in children. This loss of IQ appears to be irreversible.
A childhood loss of 7.4 IQ points is a substantial toxic effect. Substantial toxic effects should not be occurring at BLL below the CDC’s blood lead “level of concern” standard. The rationale the CDC uses for failing to lower its blood lead “level of concern” lacks merit because: 1) It is not justified from a public health perspective; 2) It is inconsistent with the CDC’s mission statement; 3) It is inconsistent with prior acts of the CDC, and; 4) It misleads health officials by implying that elevated blood lead levels below the CDC blood lead “level of concern” standard are safe for children. The CDC should substantially lower its current blood lead “level of concern” standard. Continuing to study this issue while failing to take action, when the weight of the scientific evidence warrants it, is a failure on the part of the CDC to protect young children, who are the most susceptible to lead poisoning and who are the most vulnerable in our population.
Submitted by:
Bryan Wagner, JD, MPH, REHS
Colleen Hughes, RN, PhD
Robert Sobsey, BS, REHS
RSobsey@washoecounty.us