Screening of Pesticide and Biocide Patterns As Risk Drivers in Sediments of Major European River Mouths: Ubiquitous or River Basin-Specific Contamination?

Abstract

Pesticides and biocides (PaB) are ubiquitously present in aquatic ecosystems due to their widespread application and have been detected in rivers at concentrations that may cause distress to aquatic life. Many of these compounds accumulate in sediments acting as long-term source for aquatic ecosystems. However, data on sediment contamination with current-use PaB in Europe are scarce. Thus, in this study, we elucidated PaB patterns and associated risks in sediments of seven major European rivers focusing on their last stretch as an integrative sink of particles transported by these rivers. Sediments were extracted with pressurized liquid extraction (PLE) using a broad-spectrum method recovering many compound classes with a wide range of physicochemical properties. Altogether 126 compounds were analyzed and 81 of them were detected with LC-HRMS and GC-NCI-MS/MS at least in one of the sediments. The highest number of compounds was detected (59) in River Elbe sediments close to Cuxhaven with outstanding concentrations ranging from 0.8 to 1691 mg/g organic carbon. Multivariate analysis identified a cluster with 3 ubiquitous compounds (cyhalothrin, carbendazim, fenpropimorph) and three clusters of chemicals with higher variability within and between rivers. Risk assessment indicates an acute toxic risk to benthic crustaceans at all investigated sites with the pyrethroids tefluthrin and cyfluthrin together with the fungicide carbendazim as the main drivers. Risks to algae were driven at most sites almost exclusively by photosynthesis inhibitors with estuary-specific herbicide mixtures, while in the rivers Po and Gironde cell division inhibitors played an important role at some sites. Mixtures of specific concern have been defined and suggested for integration in future monitoring programs.

Mixture toxicity in the Erft River: assessment of ecological risks and toxicity drivers

“…Main drivers of the chronic mixture toxicity for the aquatic flora were again different herbicides as well as fungicides, the preservative triclosan and the antibiotics clarithromycin and sulfamethoxazole. This is consistent with previous studies, which also found high pesticide risks particularly caused by herbicides, which were frequently detected in surface waters across Europe [35,[38][39][40][41][42][43].…”

High-resolution mass spectrometry to complement monitoring and track emerging chemicals and pollution trends in European water resources

“…This will greatly extend the list of chemicals monitored and potentially considered in future risk and impact assessments. Combining target screening with toxicity data [14] can be used to estimate the likelihood of impacts on the water quality status applying toxic units (TU) [15] or the multi-substance potentially affected fraction of aquatic organisms (msPAF) [14,16]. -Use NTS data to establish source-related contamination fingerprints [7].…”

Improved component-based methods for mixture risk assessment are key to characterize complex chemical pollution in surface waters

“…Massei et al [42] identified mixture risks and drivers for mixtures of pesticides and biocides measured in surface waters of seven large European river mouths. Lindim et al [43] studied pharmaceutical mixtures in Swedish freshwaters, and also identified key drivers of mixture toxicity.…”