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Accounting for scale of use in bird and mammal risk assessments - PS2347

Current approaches to assessing the risks from pesticides to wild birds and mammals are based on estimates of exposure for animals that are visiting pesticide-treated crops. This assesses the risk for that part of the population which visits treated crops. It does not take account of the scale of use of the pesticide, which determines what proportion of the total population is exposed. This project will develop practical ways to take account of scale of use in acute and reproductive risk assessments for birds and mammals. Such approaches could be used in two main ways: to identify pesticide uses which are sufficiently small scale that they may not require assessment at all; or to take account of scale of use when considering the ecological significance and acceptability of risks which exceed the normal decision-making criteria.

For acute risks, the project will build on recent research that has demonstrated relationships between the number of lethal doses applied per square metre and the probability of mortality in field studies. For reproductive risks to birds and mammals, the most attractive approach is to build on the “broods at risk” assessment approach to be developed in another proposed project (`Development of a practical phase-specific reproductive assessment for birds and mammals`). These local measures of risk will be combined with data on scale of use (area of crop and optionally proportion treated) to provide estimates of the proportion of the regional or national population at risk of mortality or reproductive effects. These approaches will be developed for a selection of scenarios involving minor crops and relevant species of birds and mammals (selected in consultation with PSD), and demonstrated in worked examples.

Including scale of use will create new measures of risk which will require establishment of new criteria for decision-making. The project will therefore also undertake a preliminary assessment of the potential ecological (population) consequences of different levels of the new risk measures, to assist the authorities in establishing appropriate criteria. As part of the project, a workshop will be held to discuss the results of the research with PSD, additional experts and stakeholders. This will critically review the proposed approaches and enable the authorities to take account of a range of views on decision criteria.
Objective 1: Develop approaches for taking account of scale of pesticide use in acute and reproductive risk assessments for birds and mammals.
Project Documents
• Final Report : Accounting for scale of use in bird and mammal risk assessments   (936k)
Time-Scale and Cost
From: 2008

To: 2010

Cost: £90,697
Contractor / Funded Organisations
Central Science Laboratory
Decision Support              
Environmental Impacts              
Environmental Protection              
Habitat conservation              
Health Effects              
Nature conservation              
Pesticide use              
Risk assessment and management              
Fields of Study
Pesticide Safety