Occurrence and ecological risk assessment of neonicotinoids and related insecticides in the Bohai Sea and its surrounding rivers, China. (1st February 2022)

• Record Type: Journal Article
• Authors: Naumann, Tanja; Bento, Célia P.M.; Wittmann, Andreas; Gandrass, Juergen; Tang, Jianhui; Zhen, Xiaomei; Liu, Lin; Ebinghaus, Ralf
• Is Part Of: Water research. Volume 209(2022)
• Publication Date: 2022-02-01
• Subjects: DF Detection Frequency -- EC50 median Effective Concentration -- HPLC-MS/MS Hhigh Performance Liquid Chromatography coupled to tandem Mass Spectrometry -- IS Isotopically-labeled internal standards -- LC50 median Lethal Concentration -- MDLs Method Detection Limits -- MEC Measured Environmental Concentration -- MQLs Method Quantification Limits -- NOEC No Observed Effect Concentration -- PNEC Predicted No Effect Concentration -- PP Polypropylene -- RQ Risk Quotient -- SPE Solid-phase extraction -- TPs Transformation Products -- USEPA United States Environmental Protection Agency -- v/v volume/volume -- ∑insecticides total (sum) concentration of insecticides; Neonicotinoids -- Fipronil -- Degradation products -- Seawater -- Fingerprint analysis -- Ecotoxicological risk; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2021.117912
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: Pollution of coastal areas with neonicotinoids and fipronil originate from riverine inputs. Acetamiprid and thiacloprid were abundant in seawater, indicating their persistence in surface waters. Photodegradation products of fipronil and imidacloprid were highly abundant in seawater. Fipronil and its TPs represent a potential high risk to freshwater and marine species. This study is the first to assess an ecological risk of the investigated insecticides in marine ecosystems. Abstract: Systemic insecticides like neonicotinoids and the phenylpyrazole insecticide fipronil are the most widely applied insecticides around the world. Multiple studies analyzed insecticide residues in freshwater systems, but data on seawater contamination levels are scarce. This study investigates the spatiotemporal distribution and ecological risk assessment of fipronil, neonicotinoids, sulfoxaflor and selected transformation products (TPs) in the Chinese Bohai Sea and its surrounding rivers. Well-established neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam) and TPs of fipronil and imidacloprid were frequently detected (detection frequency (DF): 42-100%) in freshwater. The median total insecticide concentration in freshwater was significantly higher in summer (72.4 ngL -1 ) than in fall (23.4 ngL -1 ), with major contributions from neonicotinoids, suggesting that pollution originates mostly from diffuse sources. In 2018, acetamiprid, desnitro-imidacloprid, fipronil-desulfinyl and thiacloprid were abundant in seawater (DF: 47–100%), indicating a high stability of acetamiprid and thiacloprid and a rapid photodegradation of fipronil and imidacloprid in surface waters. These results indicate that the continued use of these parent compounds may lead to their accumulation and/or of their TPs in shallow coastal seas. Consequently, this may lead to their transport to open seas, increasing their potential risk to marine organisms. Similarities between contaminant fingerprints in freshwater and seawater strongly suggest riverine discharges as main pollution source of adjacent coastal areas. This is the first study to perform an ecological risk assessment of fipronil, neonicotinoids, sulfoxaflor and selected TPs on marine ecosystems. Fipronil and its TPs demonstrated to be environmentally relevant with potential high risks for aquatic species. Our study provides novel insights into the fate and ecological risk of fipronil, neonicotinoids, sulfoxaflor and their TPs to marine species in shallow coastal seas. Graphical abstract: Image, graphical abstract