Mitch Kennedy, ND
Many epidemiologic studies have shown the relationship between children’s exposure to lead during developing years and the detrimental effects on neurologic development. A new study done in Mexico looked at IQ level of children exposed to lead in utero, and followed their development up to age 10. One hundred and seventy children had a mean blood lead (BPb) of 8 ug/ml in utero (range of 1-33 ug/ml). The largest declines in IQ were seen when exposures occurred during the third trimester.
Lead exposure around 28 weeks gestation is a critical period for later child intellectual development, with lasting and possibly permanent effects. There was no evidence of a threshold; the strongest lead effects on IQ occurred within the first few micrograms of BPb.
The take-home message: the current CDC action limits for blood lead levels in children do not protect against lead-associated child IQ decreases when applied to pregnant women.
Source: Schnaas L et al: Reduced intellectual development in children with prenatal lead exposure, Environ Health Perspect 114:791-7, 2006.
Mitch Kennedy, ND has a family practice in Avon, CT, and is the first ND with clinical privileges at the University of Connecticut, a teaching hospital. Before graduation from Southwest College, Kennedy earned an international reputation as a leader in pollution prevention, showing industries around the world how preventing pollution saves money.
