The Government has a scheme for ensuring pesticide products are tested and approved as safe for use before they are put on the market. As a further check government departments monitor use, in case of any unexpected adverse health effects of products on the market.
The aim of this feasibility study was to identify a group of people who work with pesticides and see if they would be able to help with this monitoring process.
HSE based the study on a group of agricultural pesticide users who have certificates of competence. They had already given permission for HSE to access information about them on a database held by the National Proficiency Tests Council (NPTC).
The study had two main parts. First, in late 1996, HSE sent questionnaires to 4000 people on the NPTC database, asking about their pesticide usage and health. And second, the records of 400 of them were matched with records at the NHS Central Register to see if their health could be followed up over time
The study concluded that pesticide users on the NPTC database would be a very good group for basing future research.
Half of the 4000 people in the survey returned the postal questionnaire, despite its length (20 pages) and the fact that, for some, it came at a busy time of year.
Over 90 per cent of those who returned questionnaires said they had used pesticides at some time in their working life. Of these, three-quarters had used some pesticides in the past year.
The number and type of pesticides they used varied a lot. For example, 10 per cent had used more than 30 different products in the past year. Roughly equal numbers worked in farming, for local authorities and in other sectors.
Most people said they were prepared to take part in a follow-up survey and gave consent for HSE to approach their employers and doctors.
These further surveys took place in 1997, and over 80 per cent of people responded. The results suggested that individuals tended to give a fuller account of pesticide usage than their employers; and that from their records doctors were normally not able to either confirm or contradict a user's opinion that pesticides had made them ill.
The second part of the study also went well. The NHS Central Register successfully matched 99 per cent of the NPTC records HSE sent to it.
In the course of investigating the use of the database for future research, the study also aimed to measure how often pesticide users felt they were made ill by their work. These results refer to ill-health which the users themselves thought was related to pesticide use.
Overall, 5 per cent of current users reported having at least one symptom in the past year which they thought was caused by using pesticides at work and about which they had consulted a doctor. A wider definition, including symptoms thought to be made worse by pesticides or about which a doctor had not been consulted, raised this to 15 per cent. Most of the symptoms were not serious; the most common was headache.
The study also asked users what personal protective equipment (PPE) they normally wore. Those who wore PPE were less likely to say they had symptoms related to using pesticides, especially if they used pesticides a lot.
Finally, the study asked pesticide users about any 'chronic' ill-health conditions they had suffered during their working life. Initial analysis of these has revealed very few cases of cancers, nerve problems or 'syndromes' sometimes thought to be linked to pesticide use.
Following the success of this study, HSE will be taking several steps to develop the NPTC database for future research into pesticide users' health.
First, HSE plans to increase the number of people matched at the NHS Central Register. The eventual aim will be to cover all the people on the NPTC database who have agreed to co-operate with HSE.
Second, HSE will run a series of surveys to find out whether people on the database are current pesticide users and to assess their past usage. And third, we will set up a new database, updated with information from the NPTC, the NHS Central Register and the usage surveys.
We will make this database available, with confidentiality safeguards, to medical researchers in HSE, other government departments and outside organisations. They have already suggested several ideas for research : for example, to look into any chronic effects of long-term low level exposure to organophosphate pesticides.
HSE inspectors will continue to expect management and people working with pesticides to meet the standards required by all relevant regulations, including those related to the use of PPE and other risk control measures.How do I find out more?
We hope that this leaflet gives the results which are of most interest to participants in the feasibility study and to other pesticide users and their employers.
HSE has produced a more detailed report on the results of the study and plans next year to publish a technical paper containing further statistical analysis of the results. If you would be interested in seeing either of these documents, or have other questions about the results or other issues raised by this leaflet, please contact the study's freephone 'helpline' number 0800 592450.
The success of this study is due in no small part to the co-operation of pesticide users and their employers. HSE is confident that future research - which will also depend on voluntary participation - will have the benefit of a similar level of goodwill.
Further advice can be obtained from HSE offices (see under Health and Safety Executive in the telephone directory). For other enquiries write to HSE's Information Centre, Broad Lane, Sheffield S3 7HQ.