Makro-Ökotoxikologie: Räumliche und zeitliche Aspekte von Insektizidbelastungen in Gewässern
Zusammenfassung der Projektergebnisse
The DFG-funded project focused on a large-scale evaluation of agricultural pesticides in surface waters of the USA. Data from numerous sources were used in order to better understand the role of various drivers in a spatial and temporal context. A number of partially complex preparational steps were taken in order to better understand the extremely large database: setting up of a graph database, evaluation of use-type and chemical class information and improved prediction of Regulatory Threshold Levels (RTL) as a measure for potential ecotoxicological risk (the latter work is conducted within a DBU PhD bursary). We showed that about 50% of the measured insecticide concentrations in U.S. surface waters exceeded their respective RTL. This is in line with values identified at the global level in a study published in 2015 in Proc. Natl. Acad. Sci USA as part of the predecessor project, which gained the attention of 15 news outlets worldwide and was referenced in six international policy documents. In the follow-up project, we furthermore showed that the RTL exceedance is more severe in agricultural surface waters compared to non-agricultural (urban) settings, despite the strong urban insecticide use known from the U.S. Multiple linear regression modelling revealed that toxicity-normalized agricultural insecticide use (i.e. use divided by toxicity) was the most important driver for RTL-exceedance in U.S. surface waters. Burst rainfall erosivity and irrigation practices also had risk-promoting effects, whereas time, catchment size, and sampling interval had risk-demoting effects. A regression model for small, medium, and large running waters was validated and used for risk mapping at the national scale. Since we identified the toxicity-normalized pesticide use as a main driver, we developed the Total Applied Toxicity (TAT) as a descriptor to quantify the used pesticide amount in terms of its toxicity. This allows for a much more relevant estimation of long-term changes in pesticide application compared to the focus on applied pesticide mass, which is prevailing in science, media and politics. We evaluated the TAT in a systemic approach for a total of 381 pesticides used in the U.S. including 1591 ecotoxicological endpoints (RTLs) and eight different groups of organisms. While the TAT decreased in vertebrates such as mammals, birds and fish, it sharply increased in aquatic invertebrates (driven by pyrethroid insecticides), in pollinators (driven by neonicotinoid insecticides) and in terrestrial plants (driven by various herbicides). We found within the 25-year study period a phase shift for aquatic invertebrates and pollinators from an initial phase of decreasing insecticide amounts to a subsequent phase of increasing insecticide toxicity. We also showed that the above-mentioned TAT increases in invertebrates and plants were also present in the main genetically-modified (GM) crops corn and soybean despite claims of reduced pesticide application in GM agriculture. The TAT results were published in Science in April 2021 and gained the attention of more than 175 news outlets worldwide. Results from the present project and the predecessor project were published up to now in a total of 12 peer-reviewed scientific papers and two further papers on the evaluation of U.S. governmental pesticide data and global neonicotinoid monitoring results will follow.
Projektbezogene Publikationen (Auswahl)
- (2012) Regulatory FOCUS surface water models fail to predict insecticide concentrations in the field. Environ Sci Technol 46: 8397-8404
Knäbel A, Stehle S, Schäfer RB, Schulz R
(Siehe online unter https://doi.org/10.1021/es301649w) - (2013) Probabilistic risk assessment of insecticide concentrations in agricultural surface waters: a critical appraisal. Environ Monit Assessm 185: 6295- 6310
Stehle S, Knäbel A, Schulz R
(Siehe online unter https://doi.org/10.1007/s10661-012-3026-x) - (2015) Agricultural insecticides threaten surface waters at the global scale. Proc Natl Acad Sci USA 112: 5750-5755
Stehle S, Schulz R
(Siehe online unter https://doi.org/10.1073/pnas.1500232112) - (2015) Pesticide authorization in the EU – environment unprotected? Environ Sci Pollut Res 22: 19632-19647
Stehle S, Schulz R
(Siehe online unter https://doi.org/10.1007/s11356-015-5148-5) - (2018). Compilation and analysis of global surface water concentrations for individual insecticide compounds. Sci Total Environ, 639, 516-625
Stehle, S., Bub, S., & Schulz, R.
(Siehe online unter https://doi.org/10.1016/j.scitotenv.2018.05.158) - (2018). Meta-analysis of Insecticides in U.S. Surface Waters: Status and Future Implications. Environ Sci Technol, 52, 14452-14460
Wolfram, J., Stehle, S., Bub, S., L.L., P., & Schulz, R.
(Siehe online unter https://doi.org/10.1021/acs.est.8b04651) - (2019). Aquatic pesticide exposure in the U.S. as a result of non-agricultural uses. Environ Internat, 133, 105234
Stehle, S., Bline, A., Bub, S., Petschick, L., Wolfram, J., & Schulz, R.
(Siehe online unter https://doi.org/10.1016/j.envint.2019.105234) - (2019). Graphing Ecotoxicology: The MAGIC graph for linking environmental data on chemicals. Data, 4, 34
Bub, S., Wolfram, J., Stehle, S., Petschick, L. L., & Schulz, R.
(Siehe online unter https://doi.org/10.3390/data4010034) - (2019). Insecticide risk in United States surface waters: drivers and spatiotemporal modeling. Environ Sci Technol, 53, 12071-12080
Wolfram, J., Petschick, L. L., Bub, S., Stehle, S., & Schulz, R.
(Siehe online unter https://doi.org/10.1021/acs.est.9b04285) - (2021). Applied pesticide toxicity shifts towards plants and invertebrates, even in GM crops. Science, 372, 81-84
Schulz, R., Bub, S., Petschick, L. L., Stehle, S., & Wolfram, J.
(Siehe online unter https://doi.org/10.1126/science.abe1148)
