Risk assessment of multiple pesticide residues

Risk assessment of multiple pesticide residues means an analysis, characterization, and possible quantification of the combined risks to health or the environment from multiple agents. The framework itself is conceptually similar to the approach used in both human health and ecological assessments. Its focus on the combined effects of more than one agent makes it different from many assessments conducted today, in which, if multiple chemicals are evaluated, they are usually evaluated individually and presented as if the others were not present. Because multiple stressors are affecting the same population, there is increased focus on the specific populations potentially affected rather than on hypothetical receptors and the requirement is that the risks from multiple agents or stressors be combined. This does not necessarily mean that the risks should be “added,” but rather that some analysis should be conducted to determine how the risks from the various agents or stressors interact. It also means that an assessment that covers a number of chemicals or other stressors but that merely lists each chemical with a corresponding risk without consideration of the other chemicals present is not an assessment of cumulative risk under this definition. The European Food Safety Authority (EFSA) published the results of on-going work to develop methodologies to assess the cumulative effects resulting from consumer exposure to pesticides. The work looks at a group of pesticides that have similar chemical structure and toxic effects to see if their impact on human health can be assessed collectively rather than just on an individual basis. The EFSA Panel concluded that only cumulative effects from concurrent exposure to substances which have a common mode of action raised concerns and needed further consideration. In order to evaluate methodologies the Panel selected some pesticides from the group of triazole fungicides on the basis of their similar chemical structure and mode of action, which are considered prerequisites for the assessment of cumulative effects. In order to address uncertainties, the application of new cumulative risk assessment methodologies required further work and that guidance on appropriate methodologies for exposure assessment was also still needed.