Sunday Times, 30 April 2000

WOMEN who breast-feed their babies could be inadvertently giving them doses of toxic pollutants that damage their ability to fight disease.

New research shows that the breast milk of many western women contains levels of polychlorinated biphenyls (PCBs) high enough to damage a child’s immune system.

The research found that such babies were several times more likely to contract chicken pox, middle-ear infections and a range of other llnesses.

The study is the first to show that high levels of PCBs can be transmitted in breast milk and that they have an impact on children’s health.

The finding contradicts previous government assurances. In 1997 Sir Kenneth Calman, then the government’s chief medical officer, said PCBs posed "negligible threats" to human health. Calman was, however, speaking before full research had been done.

The study, to be published shortly, was led by Dr Nynke Weisglas-Kuperus, a paediatrician at Sophia Children’s Hospital in Rotterdam, Holland, who studied the development of 207 babies born in the early 1990s. Half were breast-fed and half given formula. She found that many of the breast-fed babies received higher levels of PCBs than those fed formula milk. Normally, breast-fed babies suffer fewer illnesses than those who are bottle-fed, but high PCB levels destroyed this benefit.

The study looked at those children exposed to high PCB levels and found that they suffered the same rate of infectious illness as those fed formula - with some of them suffering more than normal.

Weisglas-Kuperus said: "By the age of 3Å, children with higher levels of PCBs had had more infections. This effect was more obvious in breast-fed children because they have higher levels of PCBs." But she said that, for most women, the benefits of breast-feeding outweighed the effects of PCBs.

Her findings will still be keenly scrutinised. Last week the government proposed paying mothers who breast-feed an extra £10 a week to spend on healthy food for themselves. Many health professionals have spent years campaigning for women to breast-feed and will object to anything that undermines such views.

Dr Margaret Lawson, senior lecturer in paediatric nutrition at Great Ormond Street hospital’s Institute of Child Health, said: "We’ve got very good objective evidence that breast-fed babies suffer fewer infections than bottle-fed babies. So it’s clear that, though breast-fed babies may have more PCBs, they are healthier."

PCBs came into widespread industrial use in the 1930s, but it was not until the mid-1970s that scientists realised how toxic they were. They were widely used in lubricants and insulators before being banned by most countries in the early 1980s after health fears.

Studies show that they have found their way into the air, water and soil via waste disposal and leaks from mechanical equipment. Fish and invertebrates die from even a tiny dose, while human beings and other mammals suffer birth defects and loss of disease resistance.

PCBs are still being manufactured and used in some countries, although a treaty is now being negotiated to ban them. Britain is planning to ispose of all remaining PCBs by the middle of next year, with the whole of Europe due to follow by 2010.

Recent studies carried out in Holland and America show that PCBs can damage the intelligence of unborn babies. Children born to mothers with high PCB levels can have their IQ reduced by up to six points compared with those born to women with low PCB levels.

They may also have behavioural problems. Linda Birnbaum, director of experimental toxicology at the US Environmental Protection Agency, said PCBs had subtle effects. "We’re not seeing kids without arms and legs, but we are seeing children who get ill more easily or who would have had a higher IQ without that exposure."