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Pesticide Users' Health Study

What is the Pesticide Users' Health Study?

The Pesticide Users' Health Study (PUHS) was established by the Health and Safety Executive (HSE) in the late 1990's. The aims of the study are to monitor the long-term health of individuals potentially exposed to low levels of pesticides on a longer term basis, and to help fill the gaps in knowledge about the extent and nature of pesticide-related ill health.

How did pesticide users become part of the study?

In the 1990's and early 2000's, the National Proficiency Tests Council (NPTC) issued the recognised Certificates of Competence required by users of agricultural pesticides under the Control of Pesticides Regulations 1986.

From 1994 to 2003, anyone applying for certification was invited to give their permission for HSE to access information relating to them for the purpose of medical research into pesticide use. For those who agreed, NPTC passed their name, contact details and information about their certification to HSE, and they became members of the Pesticide Users' Health Study. There are around 65,000 participants from across Great Britain.

How did we collect information about the study participants' pesticide use?

From 2004 to 2006, HSE sent a questionnaire to all members of the Pesticide Users' Health Study. This questionnaire looked at users' work with pesticides at the time, and in the past. It also asked about the types of pesticide used and the time spent using them.

How do we collect information about the study participants' health?

Around 96% of members of the Pesticide Users' Health Study have been successfully 'flagged' with NHS central registers. This means that the study team will be notified whenever a study member dies, is diagnosed with cancer, or emigrates from or returns to Great Britain. This information is provided to us on a quarterly basis by the NHS Digital (for England and Wales) and National Records of Scotland (NRS).

NHS Digital supplies cancer data on behalf of Public Health England. The information received includes health data such as the date of the event and the cancer type or cause of death, which is regarded as a special category of information. We will use this information to understand the long-term health of study participants.

We have also received information on hospital admissions for members of the Pesticide Users' Health Study. This will allow us to investigate long-term ill health, such as neurological disease and eye disease. This information was provided by NHS Digital.

How do we use the study participants' data?

The data collected by the study is used for health research purposes only and is kept strictly confidential. The data will be used to investigate whether there is any evidence of a link between working with pesticides and health. The study findings will be freely available online in HSE Research Reports or other published articles.

The findings are reported in such a way that no individual can be identified.

HSE is the sponsor for this study based in the United Kingdom. We use the information from the participant and their medical records (provided by NHS Digital and NRS) in order to undertake the study and will act as the data controller for the study. This means that HSE is responsible for looking after participants' information and using it properly. HSE will keep identifiable information about participants for fifteen (15) years after the study has finished.

The data collected about participants may be provided to researchers running other research studies in HSE or in other organisations. These might be universities or other organisations involved in health research in this country or abroad. Individuals will not be identifiable in any data shared with other approved researchers, and the data will not be combined with other information in a way that could identify an individual participant.

As a government agency we use personally identifiable information to conduct research to improve workers' health. As a publicly funded organisation, we have to ensure that it is in the public interest when we use personally identifiable information from people who have agreed to take part in research. This means that when someone agrees to participate in a research study we will use their data in the ways needed to conduct and analyse the research study.

Participants' rights to access, change or move their information are limited, as we need to manage their information in specific ways in order for the research to be both reliable and accurate. If a participant withdraws from the study, we will keep the information about them that we have already obtained.

To safeguard participants' rights, we will use the minimum personally identifiable information possible.

Health information is sensitive personal data and is regarded as 'special category' data. Sensitive personal data will only be processed for research purposes.

This study does not use automated decision-making or profiling to make decisions about individuals.

If you wish to raise a compaint on how we have handled personal data you can contact our Data Protection Officer who will investigate the matter. If you are not satisfied with our response or believe that we are processing personal data in a way that is not lawful then you may compalin to the Information Commissioner's Office (ICO).

You can contact our Data Protection Officer by email at or you can write to them at the following address:

Data Protection Officer

Health and Safety Executive

1.3 Redgrave Court

Merton Road


Liverpool L20 7HS

More information on how HSE processes data is provided in HSE's Privacy Policy Statement.

What work has been completed to date?

A number of reports and publications are freely available:

  • HSE Research Reports on cancer incidence (RR956) and mortality (RR958) among members of the study
  • An article in Occupational Medicine on mortality and cancer incidence
  • Results of the survey of pesticide usage undertaken from 2004 to 2006 has been summarised in HSE Research Report RR957

Analysis of hospital admissions among study participants is currently being undertaken.

How is the study funded?

The Pesticide Users' Health Study is funded by the Health and Safety Executive.


If you have any questions at all about the research, please contact the survey team:

Pesticide Users' Health Study

Health and Safety Executive

Harpur Hill



SK17 9JN


Or via the website Contact Form.

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