Sources, occurrence and predicted aquatic impact of legacy and contemporary pesticides in streams

Abstract

11We couple current findings of pesticides in surface and groundwater to the history of pesticide usage, 12 focusing on the potential contribution of legacy pesticides to the predicted ecotoxicological impact on 13 benthic macroinvertebrates in headwater streams. Results suggest that groundwater, in addition to 14 precipitation and surface runoff, is an important source of pesticides (particularly legacy herbicides) 15 entering surface water. In addition to current-use active ingredients, legacy pesticides, metabolites and 16 impurities are important for explaining the estimated total toxicity attributable to pesticides. Sediment-17 bound insecticides were identified as the primary source for predicted ecotoxicity. Our results support 18 recent studies indicating that highly sorbing chemicals contribute and even drive impacts on aquatic 19 ecosystems. They further indicate that groundwater contaminated by legacy and contemporary 20 pesticides may impact adjoining streams. Stream observations of soluble and sediment-bound 21 pesticides are valuable for understanding the long-term fate of pesticides in aquifers, and should be 22 included in stream monitoring programs. 23Capsule: Legacy pesticides, particularly sediment-bound insecticides were identified as the primary 24 source for predicted ecotoxicity impacting benthic macroinvertebrates in headwater streams. 25 2

Re-registration Challenges of Glyphosate in the European Union

“…It has been concluded that glyphosate and AMPA often occur as run-off from fields originating from glyphosate-based herbicide application. These residues not only became ubiquitous or "pseudo-persistent" contaminants in surface water, in periods with increasing concentrations over the years (McKnight et al, 2015;Carvalho, 2017;Primost et al, 2017), but through surface waters they were shown to be able to reach the seas as well, as documented in Germany in the estuaries of the Baltic Sea (Skeff et al, 2015). Glyphosate and AMPA were also found at up to 2.5 and 0.48 µg/l in rain and up to 9.1 and 0.97 ng/m 3 in air, respectively in the USA in Mississippi, Iowa and Indiana States in 2004(Chang et al, 2011, where both have been identified in the same period as common surface water contaminants near agricultural fields (Majewski et al, 2014).…”

Laudation to PD Dr. Wolfgang Ahlf: towards integrated approaches in sediment toxicology and its transfer to sediment quality guidelines

“…El-Mufleh et al (2013) showed that PAH are mainly sequestered in the unsoluble part of sediment organic matter (humin) [6]. Sediment bound pesticides were identified as the primary source for ecotoxicity, although in most papers this refers only to the extractable part of residues [6]. Anyway, it is obvious that sediment NER is a neglected research field which needs more attention.…”

“…For instance Luo et al stated that it is not sufficient to analyze just the extractable portions of brominated flame retardants in sediments but rather to characterize also the sequestered portions (type I NER, that might be remobilized) to get the full picture of contamination [5]. El-Mufleh et al (2013) showed that PAH are mainly sequestered in the unsoluble part of sediment organic matter (humin) [6]. Sediment bound pesticides were identified as the primary source for ecotoxicity, although in most papers this refers only to the extractable part of residues [6].…”

“…Under your leadership, we worked together [7] to develop a biotest set that would be academically recognised and justiciable. Today, the test equipment the group developed, consisting of the luminescent bacteria test (Vibrio fischeri), the algae test with Phaeodactylum tricornutum and the amphipod test with the mud crab Corophium volutator is an established standard range for risk assessment of dredged material, eluates and pore water, and especially of brackish and marine sediments [6]. Out of this research work emerged a DIN working group at a national level, which set out to enhance the biotest scene of the future with marine tests and test and validate new biotests.…”

The Effects of Antibiotics on Microbial Community Composition in an Estuary Reservoir during Spring and Summer Seasons

“…Most of the former correlative researches have been mainly focused on the conditions of relative higher antibiotic concentrations, and how these compounds affected the bacterial community in laboratory experiments, which strongly limited our understanding about the potential ecological impact of these antibiotics on actual aquatic ecosystems [49,50]. Hence in our study, high-throughput sequencing (HTS) combined with correlation network analysis to explore the co-occurrence/exclusion patterns and effects between antibiotics and the bacterial community in the actual estuary ecosystem, as well as the influences of these antibiotics on co-occurrence pattern of cyanobacterial and non-cyanobacterial taxa.…”