Doctors report on OPs

A long-awaited report from a joint working party of the Royal College of Physicians and the Royal College of Psychiatrists has said that illness from chronic organophosphate OP exposure is genuine and that symptoms must be taken seriously. Alison Craig reports.

The joint working party heard evidence from sheep-dip exposure victims themselves, and concluded that symptoms they experience are unquestionably genuine. These range from nausea and headache to severe fatigue, muscle failure and suicidal thoughts.
    Bryan Jennings, of the National Farmers Union (NFU), said: "Anyone in the room when sufferers gave evidence could not have failed to be moved by their painful experiences. The aim of the report is to make treatment for OP exposure victims far less traumatic."
    The Department of Health's Chief Medical Officer, Professor Liam Donaldson, has responded encouragingly to the report, with an initiative to involve the Royal College of General Practitioners in implementing the report's recommendations.
    "The doctors have finally acknowledged that the problem exists and that people should receive treatment for it from within the National Health Service (NHS)", says Enfys Chapman, herself an OP exposure victim, who sat on the joint working party. "If the report is implemented it will help the many exposure sufferers left languishing in the community."
    The report admits that "existing NHS clinical services do not, in the main, provide satisfactory management for those with symptoms associated with OP sheep dip exposure", and even that "the inadequacies of the NHS (and other agencies) actively inhibit good management in many cases."
    It goes on to describe how best practice could work, though it warns that the illness is poorly understood and "there is currently no evidence-based effective specific treatment for the chronic symptoms of OP sheep dip exposure." Diagnosis and management strategies are also recommended (see box). The report's authors propose that a patient's general practitioner (GP) doctor, who can liaise with the National Poisons Information Service over suspected poisonings, should remain the focal point for the patient's treatment.
    This is a questionable recommendation in the view of Ernie Patterson, chairman of the Northern Ireland Organophosphorus Sufferers' Association (see page 14). "I wouldn't expect something as complicated as this to be thrown back at the GP," he says. "The GP should not be expected to take responsibility for diagnosis and management without special training, which is vital."
    The GP can refer the patient for specialist tests, although the report is not optimistic about them. "As many (patients) are not found to have abnormalities following specialist investigations," falsely high expectations must not be raised.
    Doctors are advised not to treat patients' symptoms as 'all in the mind', and to use an eclectic treatment strategy.
    The report takes a similarly non-committal approach to the issue of pesticide sensitisation. It says experience suggests that avoidance of exposure "is a potent source of secondary disability and prolonged ill health." It also stresses: "An individual reluctant to come into contact with OPs should be made aware of the ubiquity of OPs in the environment and the impossibility of being totally free of OPs, but suitable advice about particular situations in which OPs are likely to be used may be helpful, for example in certain domestic products or arable crops at certain times."
    In fact, many product labels for OPs and carbamates include a warning to users to avoid them if under medical advice not to work with anti-cholinesterase compounds.
    The report, which ducks the issue of whether long-term low-dose OP poisoning actually does cause illnesses, has its critics. "There is nothing new here", says journalist John Harvey. "Since the Zuckerman report in 1951 it has been recognised that OP pesticides are a major risk to farmers' health."
    The Royal Colleges point to a dearth of information about pesticide exposure, and recommend further research and better biological monitoring of the workforce.
    The Pesticides Trust [now PAN UK] believes the report raises wider questions about OPs still permitted in agriculture and in a wide range of products for the home and garden. "These are highly toxic chemicals, and we shouldn't be using them", says Peter Beaumont. " They should be phased out as soon as practicably possible, and more government funding is needed for research into safe and sustainable alternatives, such as a vaccine for sheep scab."

So, in practice …
If you have suspected non-emergency symtoms of pesticide poisoning, this is the procedure you can expect your GP (doctor) to follow if the report is implemented. Some GPs do so already. Alternative practitioners in the private sector may follow a different programme, for which charges will be made.
If you seek help at an early stage, you can report the problem to a Health and Safety Executive (HSE) doctor (your GP will have full contact details). Your GP will be aware of the possibility of OP poisoning and the associated symptoms. He or she will listen to what happened, and will take you seriously. A full clinical history will be taken, comprising the following (you may be asked to write them out in advance):

Details of all exposures to pesticides, however long ago
Any temporal relationship between exposures and symptoms
Frequency and duration of exposure
Full details of the pesticides, including label details if possible
Details of any protective clothing you were wearing

A general examination will be made of major organ systems, and your general mental state will be assessed. Laboratory screening can be followed if symptoms are consistent with OP exposure, to exclude other diagnoses such as thyroid dysfunction.
Your GP will discuss and agree with you at all stages the investigation strategy, and will not raise your expectations too high: the current specialist tests are unlikely to give results. These include: full blood count including erythrocyte sedimentation rate; liver function; thyroid function; renal function; blood glucose; serum vitamin B12 concentration; chest X-ray, urine examination for albumin, glucose and blood.

Assessment of exposure

If it occurred in the previous 24 hours, this could include plasma and red-cell cholinesterase activity
If it occurred in the previous 4-5 days, this could include urinary metabolites of OPs
The results of these then need to be compared with control samples taken three months after exposure (without re-exposure)
Urinary alkylphosphate assays are only available for some OPs (not including propetamphos)
If your work, for example, puts you at risk of re-exposure, advice should be sought by your GP from HSE.

Advice on multiple chemical sensitivity which you may have can be sought from a consultant immunologist, though the waiting time may be frustratingly long. Specialist examination may then be arranged by your GP, by an occupational physician, neurologist or psychiatrist, depending on your symptoms.
Your GP will then adopt open-minded treatment, tackling each symptom vigorously: depression, for example, may be treated with existing therapies, eg anti-depressants.

The Royal Colleges report was produced by a working party, chaired by Professor John Newsom Davis and comprised neurologists, psychiatrists, and representatives from the Advisory Committee on Pesticides, the Pesticides Trust, the Pesticide Exposure Group of Sufferers, the Veterinary Products Committee, the NFU, the Royal College of GPs, and the Department of Health.

Organophosphate sheep dip: clinical aspects of long-term low-dose exposure, Report of a joint working party of the Royal College of Physicians and Royal College of Psychiatrists, November 1998/CR67.

[This article first appeared in Pesticides News No. 42, December 1998, page 3]