On Tuesday April 30 the Liberal Democrat PM Paul Tyler,
chaired a briefing session on organophosphate (OP) insecticides for MPs at
the House of Commons. It was attended by over a dozen MPs, two Peers and a
bishop, a number of lawyers, journalists and TV teams. The speakers were Dr
Goran Jamal, a consultant neurologist from Glasgow; Professor William
McKenna, the head of the Cardiology Unit at St. George’s Hospital, London;
Dr Robert Davies, consultant psychiatrist from Taunton; and Dr Anne
Spurgeon, of the Department of Occupational Health, Birmingham University.
Elizabeth Sigmund of OP Information Network also spoke.
Dr Jamal, who is currently carrying out
neurophysiological tests on sheep farmers who have been exposed to OP dips,
criticised the government’s policy on the licensing of toxic chemicals. He
warned of the inadequate testing of these chemicals, in particular in
relation to toxicity to humans. Even the ‘good’ data is incomplete, and
relies on laboratory work on animals and this data emanates entirely from
the chemical companies themselves. He questioned the absence of information
on the effect of using these substances in combination, and the
environmental and occupational conditions under which they are actually
used. The problem of assessing the long-term effects of repeated low-level
OP exposures is particularly important, not just to workers, but also to the
population at large. His own research has led him to voice grave concern at
the chronic peripheral neuropathy observed in a high proportion of his
patients exposed to OPs.
Professor McKenna then addressed the problem of OP
toxicity in the heart. He related the case of a 37 year-old Kent sheep
farmer, who, after repeated exposure of so-called ‘dippers flu’ suffered
cardiac arrest, and was only saved by the prompt action of his GP in getting
him into hospital (see PN31 p11). This patient has suffered recurring
cardiac symptoms after even mild OP exposure. Research is being carried out
in various countries into OP-related cardiomyopathy, and a paper will be
published on the possibility of the involvement of OPs and the sudden death
syndrome.
Dr Robert Davies is treating a growing number of patients
occupationally exposed to OP dips, and has published a paper on the effect
of OPs on the serotonin levels in the brain. He referred to a paper by Dr T.
Parron, about to be published on the journal Forensic Science
International, which reports a rise of 50% in the suicide rate among
agricultural workers in Andalusia in Spain between 1976 and 1986. This rise
corresponds with the introduction of OP pesticides in the industry. Dr
Davies pointed to the high rate of suicides in UK sheep rearing areas, and
stated that a properly targeted survey of rural suicide must be undertaken.
Dr Anne Spurgeon, one of the authors of a study of
dippers using OPs which showed clear signs of cognitive damage even among
people with no previous history of ill-health, told the meeting that the
institute of Occupational Health at Birmingham are currently developing a
protocol with the Department of Occupational and Environmental Medicine at
Newcastle University in a collaborative effort to extend the previous work,
which will involve neurological and neuro-psychological investigation of a
larger group, with a prospective follow-up. This is a very important study
in the light of the findings of the previous speakers, and funding is being
sought.
A review of government papers showing clear knowledge of
chronic neurotoxicity related to OP exposure dating back to 1948 was given
by Elizabeth Sigmund.
Copies of the papers are available from: OPIN, Heathfield Farmhouse, Callington, Cornwall, PL17 7HP, Tel. 01579 384492, Fax 01579 384586.
[This article first appeared in Pesticides News No. 32, June 1996, page 19]