Children are suffering from tooth defects caused by pesticides that accumulated in their mother's milk and which were passed on during breastfeeding.

In one study, up to 17 per cent of the 102 children examined, aged between six and seven years, had enamel defects caused by the family of pesticides called polychlorinated aromatic hydrocarbons.

A research team from the University of Helsinki has discovered that tooth decay can act as a marker for pesticide contamination in young children. Some of those affected in the study group had chalky lesions on their teeth, while others suffered a loss of enamel.

They found that decay was a good marker for exposure to toxic dioxins but not to biphenyl congeners found in PCBs.

Contamination could have occurred while the children were in the womb, but would have chiefly been passed on during breastfeeding. The pollutants are also found in the food chain (Lancet, 1999; 353: 206).

Whatever harm pesticides may inflict on us, they do not seem to affect the sex of newborns, researchers have found. They studied the sex ratio of children born to parents who had been poisoned by PCBs (polychlorinated biphenyls) and PCDFs (polychlorinated dibenzofurans) in Taiwan between 1978 and 1979. During the period of the study, 69 girls and 68 boys were born (Lancet, 1999; 353: 206-7).