An industrial pollutant can affect the intelligence, memory and attention of children if their mothers were exposed to high doses of it when they were in the womb.

Scientists have discovered that polychlorinated biphenyls (PCBs) can cause long term problems for the developing child.

Although PCBs were banned in many countries in the 1970s, they still remain the most common pollutants, and can easily be introduced into our systems by eating fatty fish from waters still contaminated by the pollutants.

Researchers from the Wayne State University in Detroit studied 212 children born to mothers who had eaten fish from Lake Michigan, a PCB contaminated water. At the age of 11, the children were tested for their IQ levels, and those who were the most highly exposed to PCB were three times as likely to have low average IQ scores, and twice as likely to be at least two years behind in reading comprehension. Their memory and attention span were also affected.

Even though, as newborns, the children were receiving more PCBs through breastfeeding, it seems that the damage is done in the womb when the fetal brain is still forming (N Eng J Med, 1996; 335: 783-9).

Organophosphate pesticides can damage the nerves, while the immediate effects usually within 24 to 96 hours after eating contaminated food include cranial nerve palsies, weakness in the neck and limbs, and respiratory paralysis, a researcher from the University of Alabama has said

!ABMJ, 1996; 313: 690, N Eng J Med, 1996; 335: 783-9.