Background – who is organising and funding the research?

The IMPRESS study is a large multinational research project on the assessment of pesticide exposure at work. The study involves researchers from the Institute of Occupational Medicine (IOM), the Health and Safety Laboratory (HSL) and the University of Manchester in the UK as well as the Institute of Risk Assessment Science (IRAS) from the University of Utrecht, the Netherlands.

The IMPRESS study is funded by the European Crop Protection Agency (ECPA). A project Advisory Board has been convened and its role, among others, is to ensure transparency of the project findings.

How long is the study running for?

The study officially started in September 2017 and had a duration of 3 years. Due to more time being necessary in the planning stages of the project and also COVID-19 restrictions in place for a significant duration of the project, the project is now scheduled to run until end August 2022.

What is the aim of the study?

The IMPRESS study aims to understand better how well the existing methods of exposure assessment for pesticides perform when applied within epidemiological studies (i.e. studies looking to identify the causes of health effects within a human study population) of chronic health outcomes. The intent is to use the project results to advice on improvements in research for the future.

Why is the study important?

Exposure to certain pesticides is suspected to result to several chronic diseases such as cancers, reproductive effects (e.g. reduced semen quality) and Parkinson disease. Studying chronic health diseases requires the assessment of historical exposures. However, exposure measurement data are rarely available, particularly for early years in work. Therefore, assessment of historical exposures frequently needs to be based on self-reported information such as a person’s job title, duration of employment, and/or whether they were ever exposed (yes/no) to pesticide. Naturally, such subjective exposure measures suffer from limitations (e.g. the ability of a person to remember their job or exposure history) which may affect the conclusions of a study. The large number of chemicals and chemical mixtures involved, and the seasonality and broad range of characteristics regarding their application and use further complicates matters. Understanding the performance of the applied surrogate measures in exposure assessment is therefore important to allow proper estimation of the involved risks.

What are the project team doing to achieve the projects aims?

The work required to achieve the projects aims has been split into four key tasks.

Task 1 aims to identify the most important and commonly used exposure assessment methods in chronic disease research by reviewing available scientific literature.

Task 2 aims to evaluate the ability of workers to remember their working history related to pesticide exposure. This will be achieved by comparing responses between the same questionnaires administered now and several years ago. Professional applicators and farmers from the UK and Uganda  will participate in this task.

In task 3 the adequacy of previously established mathematical equations that can be used to estimate the exposure of workers to pesticides is evaluated. For this the questionnaire information on pesticide usage collected from UK, Ugandan and Malaysian workers will be compared with the results from actual measurements of exposure in urine samples collected from the same workers. The results of these comparisons will be used to modify and improve the performance of the mathematical equations.

In the fourth and final task, the performance of some of the most important methods of exposure assessment identified in task 1 as well as of the improved mathematical equation from task 3 will be assessed in an actual statistical analysis with health data. A range of different work populations will be used in this study and the results are expected to inform future research regarding the preferred and most reliable exposure assessment methods to be applied.

What will happen to the information collected?

Storage and handling of all questionnaire and biomonitoring data will be performed in accordance with relevant National and International Data Protection requirements. Individual participants will not be identified in publications or presentations arising from this work.

Who has reviewed and approved this study?

The required research protocols are currently being drafted. When ready these will be forwarded for ethical approval in the different regional committees responsible. Details of the ethical approvals in place and those which are still to be submitted or pending, are provided in the table below.

Study	WP2: Reliability of recalled information	WP3: Assessing performance of EA methods
Prospective Investigation of Pesticide Applicators’ Health (PIPAH) Pesticide Users Health Study (PUHS)	Approved by University of Sheffield REC, Reference No: HSL28	Approved by University of Sheffield REC, Reference No: HSL29
Study of Health in Agricultural Work (SHAW)	Approved by University of Manchester REC, Reference No: 2019-5987-9976	N/A
Organophosphate exposure and general and reproductive health among farmers in Sabah : A longitudinal study	N/A	Approved by University of Manchester REC and also the Medical Research and Ethics Committee and Ministry of Health, Malaysia (NMRR-17-424-34635)
Ugandan farm workers study	Approved by Utrecht University and the Higher Degrees Research and Ethics Committee at Makerere University in Uganda	Approved by Utrecht University and the Higher Degrees Research and Ethics Committee at Makerere University in Uganda

Who should I contact for further information on the IMPRESS project?

Further information can be obtained by contacting Dr Karen Galea (Principal Investigator).