Sebastian Stehle

• Dr.
• Postdoc at Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau (RPTU)

Significance Agricultural systems are drivers of global environmental degradation. Insecticides, in particular, are highly biologically active substances that can threaten the ecological integrity of aquatic and terrestrial ecosystems. Despite widespread insecticide application to croplands worldwide, no comprehensive field data-based evaluation of...

A shifting burden In 1962, Rachel Carson's Silent Spring was published, and the world was forced to take notice of the unintended impacts of pesticides on wildlife. Since then, there has been a perceived reduction in the amount of pesticides used and a shift in the kinds of pesticides available. Schulz et al. looked at the type, amount, and toxicit...

Neonicotinoids are the most widely used insecticides worldwide. However, the widespread usage of neonicotinoids has sparked concerns over their effects on non-target ecosystems including surface waters. We present here a comprehensive meta-analysis of 173 peer-reviewed studies (1998-2022) reporting measured insecticide concentrations (MICs; n = 398...

Non-agricultural uses of pesticides are common in the U.S. and may thus lead to exposure of non-target ecosystems such as urban waterways. However, surface water exposure resulting from agricultural pesticide uses has received substantially more attention during the last decades. Here we conducted a literature review and meta-analysis of peer-revie...

Pesticides enter non-target surface waters as a result of agricultural activities and may reach water bodies in protected areas. We measured in southwestern Germany pesticide concentrations after heavy rainfalls in streams of a drinking water protection area near Hausen (Freiburg) and in the catchment of the Queich (Landau), which originates from t...

Many studies have investigated short-term peak concentrations of pesticides in surface waters resulting from agricultural uses. However, we lack information to what extent pesticides reoccur over medium (> 4 days) and longer time periods (> 10 days). We use here large-scale pesticide monitoring data from across Europe (~ 15 mil. measurements, i.e.,...

Surface waters are under increasing pressure due to human activities, such as nutrient emissions from wastewater treatment plants (WWTPs). Using the retention of nitrogen (N) released from WWTPs as a proxy, we assessed the contribution of biofilms grown on inorganic and organic substrates to the self-cleaning capacity of second-order streams within...

SystemLink is an interdisciplinary research training group funded by the German Research Foundation (DFG) involving multiple cohorts of international doctoral researchers closely cooperating at the iES Landau, Institute for Environmental Sciences, Germany. The goal of SystemLink is to investigate how anthropogenic stressors on aquatic ecosystems af...

Biodiversity is declining on a global scale. Especially tropical ecosystems, containing most of the planetary biodiversity, are at risk. Agricultural monocrop systems contribute to this decline as they replace original habitats and depend on extensive use of synthetic pesticides that impact ecosystems. In this review we use large-scale banana produ...

Expressing temporal changes in the use of pesticides, based not only on amounts (masses) but also on their toxicity for different species groups, was proposed as a sensible approach for evaluating potential environmental risks. Here, we calculated the total applied toxicity (TAT) between 1995 and 2019 for Germany, mapped it, and compared it to the...

A complete ban on pesticide use in sensitive areas, such as nature conservation areas (NCA), is currently being debated in the EU as part of the Sustainable Use Regulation. NCA are strictly protected landscapes in Germany with minimal agricultural activity (<4.5 %) that serve as vital ecological refuges. However, it is largely unknown whether surfa...

Ecosystems are complex structures with interacting abiotic and biotic processes evolving with ongoing succession. However, limited knowledge exists on the very initial phase of ecosystem development and colonization. Here, we report results of a comprehensive ecosystem development monitoring for twelve floodplain pond mesocosms (FPM; 23.5 m × 7.5 m...

Aquatic ecosystems are at risk of being impaired by various organic chemicals, however comprehensive large-scale evaluations of waterbodies’ status and trends are rare. Here, surface water monitoring data, gathered as part of the EU Water Framework Directive and comprising the occurrence of 352 organic contaminants (>8.3 mil. measurements; 2001–201...

With an ever-increasing production and registration of chemical substances, obtaining reliable and up to date information on their use types (UT) and chemical class (CC) is of crucial importance. We evaluated the current status of open access chemical substance databases (DBs) regarding UT and CC information using the “Meta-analysis of the Global I...

Regulatory threshold levels (RTL) represent robust benchmarks for assessing risks of pesticides, e.g., in surface waters. However, comprehensive scientific risk evaluations comparing RTL to measured environmental concentrations (MEC) of pesticides in surface waters were yet restricted to a low number of pesticides, as RTL are only available after e...

Although pesticide contamination in agricultural surface waters is a common phenomenon, large-scale studies dealing with the responsible drivers are rare. We used data from 259 publications reporting 5,830 individual water or sediment concentrations of 32 insecticides and their metabolites in 644 U.S. surface waters to determine the factors driving...

Fungicides are indispensable to global food security and their use is forecasted to intensify. Fungicides can reach aquatic ecosystems and occur in surface water bodies in agricultural catchments throughout the whole growing season due to their frequent, prophylactic application. However, in comparison to herbicides and insecticides, the exposure t...

Assessing the impact of chemicals on the environment and addressing subsequent issues are two central challenges to their safe use. Environmental data are continuously expanding, requiring flexible, scalable, and extendable data management solutions that can harmonize multiple data sources with potentially differing nomenclatures or levels of speci...

Agricultural insecticides occur in U.S. surface waters, yet our knowledge of their current and potential future large-scale risks for biodiversity is restricted. Here, we conducted a meta-analysis of measured insecticide concentrations (MICs; n=5817; 1962-2017) in U.S. surface waters and sediments reported in 259 peer-reviewed scientific studies fo...

The decades-long agricultural use of insecticides resulted in frequent contamination of surface waters globally regularly posing high risks for the aquatic biodiversity. However, the concentration levels of individual insecticide compounds have by now not been compiled and reported using global scale data, hampering our knowledge on the insecticide...

This chapter gives an overview on the current global pesticide use, important pesticide legislations, and the regulatory environmental risk assessment of pesticides. The threat of global agricultural pesticide use for freshwater ecosystems is exemplified for the particularly toxic insecticides by reviewing the exposure and effects of insecticides o...

Agricultural land-use frequently results in short pulse exposures of insecticides such as pyrethroids in river systems, adversely affecting local invertebrate communities. In order to assess insecticide-induced effects, stream mesocosms are used within higher tier aquatic risk assessment. Regulatory acceptable concentrations (RACs) derived from tho...

Regulatory risk assessment considers vegetated buffer strips as effective risk mitigation measures for the reduction of runoff-related pesticide exposure of surface waters. However, apart from buffer strip widths, further characteristics such as vegetation density or the presence of erosion rills are generally neglected in the determination of buff...

Highly-complex Pprocess-driven mechanistic fate and transport models and multimedia mass balance models can be used for the exposure prediction of pesticides in different environmental compartments. Generally, both types of models differ in spatial and temporal resolution. Process-driven mechanistic fate models are very complex and calculations are...

Pesticides constitute an integral part of high-intensity European agriculture. Prior to their authorization, a highly elaborated environmental risk assessment is mandatory according to EU pesticide legislation, i.e., Regulation (EC) No. 1107/2009. However, no field data-based evaluation of the risk assessment outcome, i.e., the regulatory acceptabl...

Due to the specific modes of action and application patterns of agricultural insecticides, the insecticide exposure of agricultural surface waters is characterized by infrequent and short-term insecticide concentration peaks of high ecotoxicological relevance with implications for both monitoring and risk assessment. Here, we apply several fixed-in...

Pesticides entering agricultural surface waters threaten water quality and aquatic communities. Recently, vegetated treatment systems (VTSs) (e.g., constructed wetlands and vegetated ditches) have been proposed as pesticide risk mitigation measures. However, little is known about the effectiveness of VTSs in controlling nonpoint source pesticide po...

The procedure for the risk assessment of pesticides in Germany is currently further developed from a deterministic to a geodata-based probabilistic risk assessment (GeoPRA) approach. As the initial step, the exposure assessment for spray drift in permanent crops, such as vineyards, fruit orchards, and hops, is considered. In our concept, geoinforma...

This book chapter gives an overview of synthetic pyrethroids in agricultural surface waters with particular emphasis on the aspects of exposure, effects and risk mitigation. Exposure from agricultural sources is largely short-term in nature and edge-offield runoff appears to be a rather important source of entry for both aqueous-phase and particle-...