Children exposed before birth to PCBs are more likely to have trouble reading when they reach school age, a study found.
A variety of research previously found that PCBs, a common pollutant, harm intellectual development. The latest study found signs that this damage persists through childhood.
Drs. Joseph and Sandra Jacobson, psychologists at Wayne State University in Detroit, tested 212 children whose mothers had eaten PCB-tainted fish from Lake Michigan while they were pregnant.
At age 11, the children with the highest exposure were three times as likely as other children to have relatively low IQ scores and twice as likely to lag at least two years behind in reading comprehension.
The highly exposed children were also more likely to have worse memories and attention spans.
They conclude that PCBs passing from mother to child harm the developing fetal brain. They saw no evidence that exposure to PCBs after birth through breast-feeding hurt the children’s development.
While the youngsters were not retarded, “there was a substantial increase in the proportion of children at the lower end of the normal range who would be expected to function more poorly in school,” the psychologists wrote in today’s issue of the New England Journal of Medicine.
PCBs polychlorinated biphenyls - were once used to insulate electrical transformers.