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Scientific Community Calls for Improved Pesticide Risk Assessment to Protect Pollinators

Members of the scientific community are calling for authorities to learn from past mistakes in pesticide risk assessment. Scientists recall the devastating effects of previous generations of neonicotinoid-based insecticides and the damages of widespread dependence on extensive pesticide use. As a result, scientists are gathering on different fronts to insist on necessary measures to reduce the risks of pesticide use in the future.

In a recently published letter in Nature, signatories call for current and future risk assessment procedures to consider the various factors that affect the health of bees and other pollinators. According to the experts, a robust evaluation should assess the effects of pesticides in combination with other risk factors "under ecologically realistic conditions" [1]. Responsible agencies and institutions should not only consider multiple factors, but they should also extend their scope of analysis. Besides measuring acute and lethal effects, they should also secure long-term monitoring and assess sub-lethal effects. Moreover, it is necessary to evaluate unacceptable reductions of colony strength and the general impact of pesticides in conjunction with other plant protection products and pollution on the overall health status of pollinators.

Parallel to the recent letter published in Nature, another letter published in Science calls for improved risk assessment in Europe [2]. The letter counts at this moment with more than 400 signatures from the scientific community ( [3]. Co-signatories support the European Food Safety Authority (EFSA) and the EU member states applying an ambitious risk assessment. Unfortunately, member states refused to adopt EFSA's 2013 Bee Guidance document [4] to update risk assessment of pesticides for over eight years.

Currently, they are trying to advance the discussion by determining if EU countries should establish a general maximum threshold of acceptable reduction in colony strength for pesticide risk assessment. In a recent AGRIFISH meeting at the Council of the EU, ministers agreed, for the most part, on the European Commission's proposal to have a harmonised Specific Protection Goal of 10% effect of pesticides on colony size [5]. However, establishing 10% of losses in the honeybee colony size from pesticides is highly problematic. First, it contradicts scientifically sound risk assessment. In 2013, EFSA proposed a 7% acceptable value based on scientific evidence for pesticide risk assessment. Other studies in the field demonstrated the feasibility of detecting up to 5% impact of pesticides in colony strength [6]. Nonetheless, co-signatories of the letter assert that the only genuinely acceptable level of impact from pesticides would be 0%.

Signatories and supporters of the letter request an ambitious and scientifically sound risk assessment. Since pollinators play a vital role in maintaining healthy ecosystems, their protection is crucial to accomplish the EU's goals for environmental sustainability.

Besides claims to boost the protection of bees and other pollinators from pesticides, scientific evidence continues to point towards the need for strengthened risk assessment. For example, a recent publication reveals how new insecticides still pose great risks for honeybee health. The scientific article gathers and analyses toxicological data and points towards the chronic effects of long-term exposure of bees to pesticides. Furthermore, significant risks remain a concern even for newer generations of insecticides, including Flupyradifurone. It is an active ingredient that shares some characteristics with already banned neonicotinoids in Europe, such as Imidacloprid. Researchers found that exposure to Flupyradifurone had adverse effects on bees' behaviour in the short term and "reduces bee survival and food consumption" in the long term [7].

The scientific community's request for an improved risk assessment of pesticides is crystal clear, and the evidence supports their claims for better protection of bees and other pollinators. It is now time to align political will with scientific evidence and secure the future of pollinators and thus of healthy ecosystems.

[1] Fisher, A. 2021. "Protect pollinators — reform pesticide regulations." Nature 595, 172.

[2] Simon Delso, N., Aebi, A., Arnold, G., Bonmatin. J. M., Hatjina, F., Medrzycki, P., Sgolastra, F. "Maximise EU pollinator protection: Minimise risk." Science 16 Jul 2021: Vol. 373, Issue 6552, pp. 290.

[3] - Online form for signature collection with the complete list of signatories.

[4] EFSA. 2013. "Guidance on the Risk Assessment of Plant Protection Products on Bees (Apis Mellifera, Bombus Spp. and Solitary Bees)". EFSA Journal, 11(7): 3295. 266 p.

[5] BeeLife. 2021. "Bees Still at Risk as EU Member States Deem Significant Losses Acceptable."

[6] Osterman J et al. 2019. "Clothianidin seed-treatment has no detectable negative impact on honeybee colonies and their pathogens". Nature Communications, 10(1): 692.

[7] Tosi, S., Nieh, J. C., Brandt, A., Colli, M., Fourrier, J., Giffard, H., Hernández-López, J., Malagnini, V., Williams, G. R., Simon-Delso, N. "Long-term field-realistic exposure to a next-generation pesticide, flupyradifurone, impairs honey bee behaviour and survival." Communications Biology Vol. 4, (805).


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