Macro-ecotoxicology: Spatial and causal implications of insecticide contamination in surface waters

• Applicant: Professor Dr. Ralf Schulz
• Subject Area: Ecology of Land Use
• Term: from 2011 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 210606601

A meta-analysis of insecticide exposure in global surface waters (SCHU2271 6-1) has revealed for the first time that, although a rare event, about 50 percent of the cases (n = 11,300), in which an insecticide concentration had been quantified, represented concentrations above the regulatory threshold levels (RTL). Newer substance classes, i.e. pyrethroids showed even higher RTL exceedances and the situation in countries with more elaborated environmental legislation was only marginally better, a fact that had been addressed in detail for the EU risk assessment. The previous study was based solely on data from the scientific peer-reviewed literature leading to restrictions in spatial and causal relationships to be drawn. The present project thus aims at analysing an entirely new dataset (see graph on proposal title page), namely the insecticide contamination data for surface waters from the USA provided by the US Geological Survey and the US Environmental Protection Agency. The high spatial resolution and the multitude of additional information available in this dataset combined with its sheer size (more than 100,000 cases of measured insecticide concentrations plus non-detects) allows to address a set of entirely new research hypotheses at a large spatial scale: I) insecticide use rate is a key parameter for spatial patterns in RTL exceedance rates; II) A conclusive large-scale risk evaluation can be achieved based on governmental and scientific monitoring data and differences in monitoring concepts on the discerned risk outcomes be quantified; and III) Current available, comprehensive global neonicotinoid field data enable a conclusive evaluation of their exposure characteristics and risks for aquatic ecosystems, as well as a comparison of aquatic risks with those of other insecticide classes. Alongside of testing these hypotheses, the current project evaluates also the contribution of mixtures and metabolites to overall risks and delineates risks from US agricultural and urban insecticide uses. The present project requires generation, handling, quality assurance and evaluation of a very large and sensitive multi-parameter dataset and solid knowledge in the risk assessment of pesticides. The present approach should contribute to the definition and establishment of a new research field on macro-ecotoxicology.

• DFG Programme: Research Grants