Dr Joe King, a former scientific civil
servant, says low-level exposure to organophosphates (OPs) can cause chronic
ill-health effects. He has made these comments in a report(1) to the UK
Committee on Toxicity of Chemicals in Food, Consumer Products and the
Environment (COT) which has established a Working Group on OPs.
The Working Group, which reports to the Department of Health
and MAFF, was convened to advise on whether prolonged low level exposure to OPs
can cause chronic ill health effects. The Working Group stressed that it was
keen to receive information from as many sources as possible.
In recent years a plethora of reports leave the issue of
illness from long-term exposure to OPs in doubt, according to the government's
position on the subject. Dr King contends a link was incontrovertibly
established by Brain(2) and Hunter(3) well over forty years ago, stating that
non-severe exposure to OPs can produce chronic effects in humans.
Dr King is concerned that COT is only considering the effects
of OPs on acetylcholinesterase enzymes (that are vital for the nervous
system to function normally). The Department of Social Security, for example,
rules on claiming benefit for disability resulting from occupations involving
poisoning by 'compounds of phosphorus' (including OPs) refer not only to
damage to human acetylcholinesterase but, because of the difficulty of
distinguishing between them, also to damage to other enzymes.
COT decided not to address carbamate insecticides which, like
OP insecticides, are anti-cholinesterases. "It seems completely in-valid to
attempt to distinguish between chronic effects caused by OPs and chronic effects
associated with carbamates," Dr King said.
Not everyone is aware of the wide spectrum of effects which
anti-cholinesterase compounds such as OPs and carbamates have on human central
nervous systems. This major topic was dealt with thoroughly by Ballantyne and
Marrs in 19924. They list 31 human and related effects caused by anti-cholinesterases
which have evidently been available to relevant government departments since the
early 1990s. Dr King concluded: "It is astounding that studies of the dangers
to human health resulting from these insecticides were not undertaken years ago,
and that appropriate actions, formulated in the light of the precautionary
principle, were not taken to obviate these dangers."