Reuters  [Printer-friendly version]
November 7, 2006

EXPOSURE TO CHEMICALS MAY HARM YOUNG BRAINS

[Rachel's introduction: Researchers warn that the developing brain is
more susceptible to the effects of toxic chemicals than an adult
brain and any interference could have permanent consequences. They
call for a precautionary approach and say strict regulations should
be enforced for any substance which is shown to have a toxic effect.]

By Patricia Reaney

LONDON (Reuters) -- Exposure to industrial chemicals in the womb or
early in life can impair brain development but only a handful are
controlled to protect children, researchers said on Wednesday.

There is also a lack of research and testing to identify which
chemicals cause the most harm or how they should be regulated, they
added.

"Only a few substances, such as lead and mercury, are controlled with
the purpose of protecting children," said Philippe Grandjean of
Harvard School of Public Health in Boston, Massachusetts and the
University of Southern Denmark.

"The 200 other chemicals that are known to be toxic to the human brain
are not regulated to prevent adverse effects on the fetus or a small
child," he added.

In a review published online by The Lancet medical journal,
Grandjean and Philip Landrigan of the Mount Sinai School of Medicine
in New York identified 202 industrial chemicals known to be toxic to
the human brain.

They suggested millions of children worldwide may have been harmed by
toxic chemicals and may suffer learning disabilities and developmental
disorders. But only substances such as lead, methylmercury and
polychlorinated byphenyls (PCBs) have been sufficiently studied and
regulated.

"Chemicals that can interfere with brain function -- that are toxic to
the brain -- should be considered toxic also to the developing brain,"
Grandjean told Reuters.

"We should protect developing brains from exposure to these
substances. We also need to examine industrial chemicals for these
kinds of effects because it is not being done systematically," he
added.

The researchers warned the developing brain is more susceptible to the
effects of toxic chemicals than an adult brain and any interference
could have permanent consequences.

They called for a precautionary approach and said strict regulations
should be enforced for any substance which is shown to have a toxic
effect.

Professor Mark Hanson, of Southampton University in England, described
the review as a timely report which will stir up debate and generate
more research.

"There is no need to panic, but we can't ignore this possible
problem," he said in a statement. "And of course it's no accident that
the populations in which development and education are challenged in
other ways... in poor parts of the developing world, are also the
areas in which such pollutants are abundant."