Round up of OP news

Government gives OPs the OK  
Douglas Hogg, the Agriculture Minister announced on 17 February that an investigation of OP sheep dips by the Veterinary Products Committee (VPC) has concluded that they are safe when used according to the manufacturers' instructions. Mr Hogg said: "The VPC has carefully examined the effectiveness of the Certificate of Competence Scheme and other issues relating to the use of OP sheep dips."  He concluded: "There is no scientific justification for withdrawing OP sheep dips from the market."  
    However the Labour Party has promised a moratorium on OP sheep dips if it wins the general election (see page 19).  
    The VPC review of the effectiveness of the Scheme recommended measures including:  

• the marketing of OP sheep dips should continue;  

• the Certificate of Competence Scheme should be extended to include users of OP dips;  

• labelling of OP dips should be simplified;  

• there should be a mechanism for informing water regulators on the use of sheep dips and consulting them on the means of disposal;

• further basic research is needed;  

• there should be a review on non-OP dips within a year.

Those campaigning against the use of OPs remain to be convinced by these latest assurances by the Minister.

Resignation of VMC member  
A member of the Veterinary Medicines Committee's Medical and Scientific Panel has resigned over a Committee ruling which he believes will prevent its members from appearing as expert witnesses in Court proceedings with regard to the human health aspects of exposure to OPs.  
    Dr Goran Jamal, Consultant and Senior Clinical Lecturer at the Institute of Neurological Sciences attached to the Department of Neurology at Southern General Hospital, Glasgow, announced earlier this year that he found himself unable to agree to this code of conduct introduced to the Committee. As a member of the licensing committee for veterinary OPs - such as sheep dips - he would be in conflict with the Committee by appearing as an expert witness in Court.

Doctor's seminar  
The Royal Society of Medicine (RSM) hosted a practitioners' training seminar on 15 January on the toxicity of OPs. A number of doctors and researchers addressed the meeting. Points of interest were:

• Anaesthetists are now warned that those patients with a history of chronic OP exposure may react adversely to anaesthetic.  

• OPs can have acute, intermediate and long-term effects. One doctor questioned whether some of the intermediate effects - limb paralysis following on one to four days after an acute exposure- might not be due to insufficient treatment with the antidote atropine at the acute stage.  

• Electrophysiological work suggests that OP exposure can produce greater uncertainty and greater variation of response in the central nervous system, which could have relevance for psychological states.  

• Long-term low doses may produce physical damage to the nerve fibres well before any symptoms show.

Improving OP treatment  
The Royal College of Physicians and Psychiatrists has set up a Working Group, with support from the Department of Health, to advise on the clinical management of patients with symptoms that may be due to OP poisoning. It is hoped that the Working Group will include sufferers.

Farm company drops OP  
Velcourt, which farms some 65,000 acres, has announced that it will not use dimethoate, a widely used OP insecticide, to control aphids and thrips on certain crops. It will only continue to use dimethoate to control wheat bulb fly because there is no alternative. The long-term aim is to phase out all use of OPs.

[This article first appeared in Pesticides News No. 35, March 1997, page 7]