EFSA takes forward work on cumulative effects of pesticides

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.

EFSA’s Panel on Plant Protection Products and their Residues (PPR) concluded that it would be necessary to reach international consensus on which groups of pesticides could be looked at together through a cumulative risk assessment approach. The Panel specified that 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.

In a previous opinion on the subject, the PPR Panel considered all types of combined toxicity of pesticides including the interaction of different chemicals. The 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 proposed in EFSA’s previous opinion[1], the Panel selected some pesticides from the group of triazole fungicides[2] on the basis of their similar chemical structure and mode of action, which are considered prerequisites for the assessment of cumulative effects. It should be emphasised that this work can not be considered as a definitive risk assessment of triazoles.

The Panel evaluated many scenarios, involving long and short term toxicological effects, and addressed questions that may be relevant to decision makers in setting MRLs or in assessing the actual exposure to pesticides. The evaluation was based on recent data on triazole residues in food as well as data on food consumption.

EFSA’s work on cumulative risk assessment, including the findings of this opinion, contributes to the establishment of Maximum Residue Levels (MRLs), the levels of pesticide residues allowed in food to ensure consumer protection and good agricultural practices. This initiative is also part of EFSA’s on-going commitment to be at the forefront of developing risk assessment methodologies. It also follows recommendations listed in EFSA’s previous opinion and is part of EFSA’s broader work on cumulative risk assessment, following its “Scientific Colloquium on Cumulative Risk Assessment”[3] in 2006, which helped guide further developments in the field.

[1] “Opinion to evaluate the suitability of existing methodologies and, if appropriate, the identification of new approaches to assess cumulative and synergistic risks from pesticides to human health”, EFSA, April 2008.

[2] Eleven triazole fungicides were selected: bitertanol, cyproconazole, difenoconazole, diniconazole, epoxiconazole, flusilazole, propiconazole, myclobutanil, tebuconazole, triadimefon and triadimenol.
[3] For more information on EFSA's 7th Scientific Colloquium - Cumulative Risk Assessment of Pesticides to Human Health

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