KEY POINTS:
Chemical pollution may have harmed the brains of millions of children around the globe in what scientists are calling a "silent pandemic".
The world is bathed in a soup of industrial chemicals which are damaging the intellectual potential of the next generation and may increase the incidence of degenerative conditions such as Parkinson's disease, they say.
One in every six children has a developmental disability, such as autism, attention deficit disorder or cerebral palsy, the effects of which may be lifelong.
The role of low-level pollutants such as lead and mercury on the developing brain have been recognised for decades and measures taken to reduce exposure to a minimum.
But scientists from the Harvard School of Public Health in Boston say there are at least 202 chemicals with the capacity to damage the human brain whose effect at low levels of exposure are unknown.
They say limits for exposure to chemicals should be set for pregnant women and young children, recognising the unique sensitivity of the developing brain.
Philippe Grandjean, visiting professor at Harvard and lead author of the review, published in the Lancet online, said: "The human brain is a precious and vulnerable organ. Even limited damage may have serious consequences ... We are talking about the brain development of future generations. There will be an enormous cost of not regulating exposure."
But critics accused the scientists of scaremongering and said their claim of a silent pandemic was a "gross overstatement".
All 202 chemicals listed by the authors have been shown to cause serious injuries when ingested or used in suicide attempts. They include chemicals used in common household products, such as aluminium in saucepans and drink cans, acetone in nail polish remover and ethylene glycol in antifreeze.
But the main exposure is through contamination of the environment during manufacture, when the chemicals seep into the ground water, are carried in the air or contaminate food.
"The combined evidence suggests that neurodevelopmental disorders caused by industrial chemicals have created a silent pandemic in modern society," the authors write.
"Although these chemicals might have caused impaired brain development in millions of children worldwide, the profound effects of such a pandemic are not apparent from available health statistics.
"Only a few chemical causes have been recognised, so the full effects of our industrial activities could be substantially greater than recognised at present."
Fewer than half the thousands of chemicals used in commerce have been tested for toxicity and they say an accelerated testing programme is vital.
They estimate the total number of chemicals with toxic effects on humans at more than 1000, five times the number whose damaging effects have been documented.
Commenting on the review, Professor Nigel Brown, dean of medicine at St George's School of Medicine, University of London, said: "This is a campaigning article. In their enthusiasm the authors verge on scaremongering. [Their claim] of a silent pandemic is a gross overstatement.
"It is possible that there is a problem. We should be aware of this and we should study it, but there is currently not a shred of evidence of a pandemic."
- INDEPENDENT
