Systemic plant protection substances and products: how to assess the risk for bees? A beekeepers point of view

Abstract

contribution to session II Test and risk assessment Background: The current plant protection products (PPPs) assessment is no more suitable when applied to systemic substances since systemic chemicals can contaminate nectar and pollen during a long length of time. Largely focused on the acute toxicity, the current assessment scheme does not take into account several elements i.e. the chronic toxicity, the possible synergies between substances, and between pathogens and PPPs. Possible bee contamination through nectar and pollen leads to a specific exposure, mainly oral, concerning the hive bees, including larvae, drones and queens, as well as potentially delayed through the stored honey and pollen consumption. Moreover, regarding the long-term exposure, sublethal chronic effects should be taken into account. Results: For such substances we would take both the chronic toxicity and the acute toxicity measurements into consideration. Therefore the TER should be calculated based on the lowest LD50 and in the case of risk, the PEC/PNEC ratio should be measured and calculated for various behaviours. A larvae test should also be performed. Tunnel tests may be helpful but the exposure to the PPP cannot be proven and the bee behaviour observation is currently inaccurate. Further research on the effect of small doses of PPP on the bee immune system seems more than necessary. Conclusion: A new assessment scheme, which takes these parameters into account, is the core of ourcontribution. Keywords: Assessment scheme, chronic toxicity, sublethal toxicity, synergies, larvae test, PEC, PNEC, TER.