TEMPEST - A Task Exposure Matrix for Pesticides

The Background to the TEMPEST project

Introduction to the reasons and methods used in the design and construction of TEMPEST

The development of TEMPEST- the Task Exposure Matrix for PESTicides- was done as part of a joint project by the Department of Environmental and Occupational Medicine (DEOM) at the University of Aberdeen and the Institute of Occupational Medicine in Edinburgh. The project was funded by the UK Department of Food, Environment and Rural Affairs (DEFRA). The project is referenced here, and the final report for the full study can be downloaded from here .

Two aims of the project were to:

gather information on the use of pesticides in Scotland between 1945 and 2005 and, based upon this information;
develop a Task Exposure Matrix (TEM) to enable the reconstruction of individual's personal exposure levels over time.

A TEM can be particularly useful for the investigation of possible links between the use of and exposure to pesticides and the development of ill-health.

The GEOPARKINSON study - predecessor to TEMPEST:

The study team had previously worked on the GEOPARKINSON study. This was a large European multi-centre study that explored the relationship between genetic, environmental and occupational factors and Parkinson’s disease. (GEOPARKINSON is comprehensively described here http://www.abdn.ac.uk/deom/newsgeop.shtml and here http://oem.bmj.com/cgi/content/full/64/10/666). One of the findings of this earlier project suggested a link between pesticide exposure and the development of Parkinson’s disease but there was insufficient detail to determine if one or more particular pesticide types were responsible for this association.

The subsequent TEMPEST study aimed to establish a mechanism to characterise exposure to specific pesticide classes, rather than simply grouping the many hundreds of chemicals referred to as ‘pesticides’ into one exposure agent.

The GEOPARKINSON project had used a job-exposure matrix (JEM) to estimate how much pesticide a person had been exposed to over their lifetime. While this method is an improvement on simpler methods of classification, such as simply ever/never exposed, that JEM assumed that all the people with the same job title performed the same tasks, in the same way. This is obviously an oversimplification, particularly where the job title may be as general as ‘farmer’ or ‘farm labourer’, yet the range of tasks done, the pesticides used and pesticide application methods can all vary considerably.

TEMPEST aimed to address this variability by enabling estimates of exposure to be refined, by taking into account other information available about the pesticides, concentrations used, tasks done and the application methods used, all of which can vary with geographical, temporal and other crop or animal factors.