Akademie Fresenius had invited pesticide experts to their international AGRO Conference "Behaviour of Pesticides in Air, Soil and Water" in Mainz/Germany on 18 and 19 June for its twentieth staging. For two whole days, experts from the national, European, Canadian and Chinese authorities discussed the current challenges and latest developments in the assessment, authorisation and application of pesticides with scientists and representatives from the plant protection industry. Akademie Fresenius had made this possible by winning the support of experts from Germany, the EU countries and overseas.
The agenda included a comparison of the methods and results of the latest risk assessments carried out at both national and European level. Representatives from the European Food Safety Authority workgroups reported on where the harmonisation of the different approaches to assessment currently stood. Further topics included laboratory experiments and the exchange of data on the application of glyphosate and aminomethylphosphonic acid (AMPA). In addition, the participants discussed whether and how spray drift could be incorporated into the risk assessment process.
New EFSA guidance document for assessing exposure to soil organisms
Michael Stemmer of the Austrian Agency for Health and Food Safety (AGES) introduced the new guidance document for the exposure assessment of soil organisms to plant protection products (PEC Soil Guidance = Predicting Environmental Concentrations) issued by the European Food Safety Authority - EFSA. This guidance document offers a guide for all types of concentrations that are needed for assessing ecotoxicological effects: The concentration in total soil and the concentration in pore water. The recommended exposure assessment procedure consists of several tiers. To facilitate an efficient use of the tiered approach in regulatory practice, special software tools have been developed. EFSA is currently preparing training sessions and webinars for the coming year.
Planning buffer zones individually and efficiently – to prevent the transfer of pesticides
Nadia Carluer of the French Irstea research institute presented the BUVARD online tool. This tool can be used to plan vegetative buffer zones to limit the transfer of pesticides from neighbouring plots, thus reducing the overall presence of pesticides in aquatic areas.
Strips of land covered in grass or woodlands have been proven to reduce the transfer of pesticides through runoff. The effectiveness of these buffer zones depends on how they are designed and maintained and needs to be adjusted according to their agronomic, pedological and climatic context. The BUVARD online tool (BUVARD = Buffer strip runoff Attenuation and Pesticide Retention Design tool) facilitates such calculations. BUVARD can be used to simply calculate variables and create different scenarios. Nadia Carluer is convinced that “BUVARD makes it possible to design each individual buffer zone as well as possible through taking all the local features into consideration.” BUVARD is currently limited to french content because of the rainfall data availability.
Buffer zones can also be set up and calculated online to reduce the transfer of pesticides via. spray drift. To achieve this, Canada’s Pest Management Regulatory Agency has developed an online calculator which provides the users with exact configurations which take the wind speeds, temperatures, spray quality and the type of sprayer into account. John David Whall presented this calculator during the conference. It is easy to find in the web by simply searching for “buffer zone calculator” and can be used free of charge.
Progress in reducing spray drift through new technologies
Neil Mackay of FMC Agricultural Solutions (Harrogate, Great Britain) is convinced that there are now numerous options available for conducting informative risk surveys and introducing effective measures to reduce spray drift. Modern technology to reduce spray drift (SDRT: Spray Drift Reduction Technology) could, in his opinion, become the “new regulatory baseline”. He stated that robust calculation models which were able to access large and detailed data records for validation purposes were required. Nowadays, experience had shown that spray drift was highly manageable. Modern technologies for reducing spray drift could be adapted to the landscape and local conditions and were often used.
Challenge facing efficient risk assessment: Good communications between all concerned
In his presentation, Jos Boesten of the Wageningen University dealt with the challenge of defining Exposure Assessment Goals (ExAGs). In his opinion, the difficulty lay in correctly combining the two elements “effect” and “exposure” in the risk assessment process. According to Jos Boesten, the underlying problem is the definition of coherent combinations of exposure assessment and effect assessment goals. Ecotoxicological experts and exposure experts mostly reasoned and worked within the scope of their own definitions and in worlds where their own goals applied which does not lead to a coherent overall risk assessment. This inadequate cooperation has been a limiting factor for improving risk assessments for organisms. “Where there are such communication problems in assessing the risks of pesticides, both parties are always to blame – it is never the fault of one or the other.”
In order to build a bridge between these two worlds – exposure and effects – and bring them closer together, Jos Boesten suggested setting up work groups as part of the risk assessment process in which the same number of ecotoxicology experts and experts for assessing the behaviour of pesticides were represented. Together, they could develop coherent packages of exposure and effect assessment goals. However, the stimulus for putting these groups together had to come from the top management. The bottom-up approach has been shown incapable of solving the problem.
Die Akademie Fresenius GmbH