"By BBC News Online's Environment Correspondent Alex Kirby
A leading American scientist says he believes pesticides may be a far more
serious public health threat than anyone has realised.
Nicholas Ashford, Professor of Technology and Policy at Massachusetts
Institute of Technology, says he thinks chemicals are the most serious
environmental problem facing industrialised countries today.
Professor Ashford - who is also an advisor to the United Nations
Environment
Programme - is known for his work on the theory of multiple chemical
sensitivity (MCS).
The theory suggests people can become sensitised by exposure to one form
of
contamination so that they are then liable to be affected by a whole range
of other pollutants, including detergents, traffic fumes and tobacco
smoke.
There is no known cure for MCS.
Evidence in the UK
It may sound a far-fetched theory. But the experience of many British
sheep
farmers gives it credence.
Hundreds of them have become ill after dipping their animals in
organophosphate (OP) sheep dips. The symptoms range from the fairly mild
sneezing and runny eyes of 'dipping 'flu' to muscle spasms, insomnia and
overpowering fatigue. Some farmers say they have been driven to the brink
of
suicide.
OPs are highly toxic, derived from the same group of chemicals that the
Nazis used in World War Two to manufacture nerve gases. Crucially, many
farmers re****t that after exposure to OPs, they find that their symptoms
can
then be triggered off by exposure to a range of other chemicals.
And Professor Ashford thinks that OPs may be one of the most common
initiators of MCS.
Patients become sensitised
OPs are not used exclusively in sheep dips. They are also used for
fumigating public trans****t vehicles, in shampoos, and in flea collars. So
they are widely available.
The other chemical which Professor Ashford believes may be a principal
cause
of MCS is a compound called permethrin, which is used as a woodworm
treatment. It is sprayed in about 5,000 British homes every week.
He and his colleagues have found that some patients, once sensitised by
exposure to a chemical, react to subsequent levels of exposure so low that
the techniques available in most laboratories cannot detect them at all.
Doctors baffled
And the baffled doctors, he says, unable to find a clear cause for the
problem, tend to assume that it is all in the mind.
Professor Ashford believes the huge rise in pesticide use over the last
half
century could explain many illnesses, ranging from skin rashes and
breathing
problems to cancers and birth defects.
Other research in the United States suggests that about one-third of the
population -- sixty million people -- may be affected in some way.
Professor Ashford says: 'Pesticides are nerve poisons; they damage the
brain
and they are also known to be endocrine disruptors' (synthetic chemicals
which interfere with naturally produced hormones).
He wants to see an immediate reduction in pesticide use until the effects
are better understood, and is pressing for the formation of a European
Union
environment unit to study the problem.
The Health and Safety Executive has commissioned a British study of MCS
from
the Institute of Medicine. A re****t on OP sheep dips, by the Royal College
of Physicians and the Royal College of Psychiatrists, is due to be
published
in November."
http://tinyurl.com/2fwmc
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