Background: From 1978 to 1979, a group of people in Taiwan were exposed to high levels of heat-degraded polychlorinated biphenyls (PCBs) owing to accidental ingestion of contaminated rice oil. Children born to mothers following the exposure ('Yucheng' children) were known to have hyperpigmented skin and other dysmorphology after birth.
Aims: To determine the effect of prenatal exposure to PCBs on cognitive development in Yucheng children.
Method: One hundred and eighteen Yucheng children prenatally exposed to PCBs and degradation products, and community-matched control children who were exposed to background levels only, were followed from 1985 to 1998. The Bayley Scale for Infant Development, Chinese version of the Stanford-Binet IQ Test, Raven's Coloured Progressive Matrices and Raven's Standardised Progressive Matrices were used to assess the cognitive development of these children.
Results: The Yucheng children scored lower than control children on each of these methods of measurement between the ages of 2 and 12 years.
Conclusions: Prenatal exposure to PCBs and their derivatives has long-term adverse effects on cognitive development in humans.