Occurrence of Neonicotinoid Residues in Danube River and Tributaries

Abstract

Occurrence and fate of 6 neonicotinoid insecticides belonging to different chemical classes were investigated in the aqueous phase of surface water at 16 sampling locations along the Romanian side of the Danube River and its three main tributaries (Jiu, Olt, Arges). This is the first report on the neonicotinoid occurrence in the Danube River and three tributaries. It was observed a contamination of Danube River and its tributaries, higher in planting period than pre-or post- planting period, with the next compounds (detection frequency and the concentration range): thiamethoxam (68.7%, 0.9-3.8ng/L), clothianidin (64.6%, 0.84-9.6ng/L), nitenpyram (52.08%, 0.39-11.1ng/L), imidacloprid (31.2%, 0.5-8.2ng/L), acetamiprid (16.6%, 0.84-12.7ng/L). The four main neonicotinoids (clothianidin, thiamethoxam, imidacloprid, nitenpyram) follow the classic pattern in which concentrations and frequency increase during the planting period and that is correlated with seed crop treatment. Total neonicotinoid levels present in investigated Rivers, reaching up to 31.6 ng/L, may affect aquatic invertebrates that are most susceptible to these insecticides. For clothianidin and nitenpyram were obtained positive correlations between the percentage of the area planted with cereals and concentrations of this compound (r= 0.574, r =0.665) which indicate their use in agricultural area. For imidacloprid were obtained positive correlations between percent of permanent cultivated crop in urban land and concentrations of this compound (r =0.264, r =0.877).

Liquid Phase Chromatographic Methods Applied to Determine Emerging Contaminants in Environmental Samples

“…The method of analysis of the compounds of interest has been previously published [25, 27,28]. Neonicotinoid determination was performed using an Agilent 1260 liquid chromatograph in tandem with the Agilent quadrupole 6410B triple mass spectrometer provided with the ionization electrospray ESI source in the positive mode.…”

“…These values correlate with the short half-life of acetamiprid 4.7 days, which is the lowest, and imidacloprid has a half-life by dissipation in water of 30 days.2 compounds (nitenpyram and clothianidin) were not detected in the analyzed wastewater samples. The decanted waters from the station were contaminated with the following compounds (average concentrations in the 4 days of study): dinotefuran 3.7 ng/L, imidacloprid 55.9 ng/L, acetamiprid 1.95 ng/L thiamethoxam 15.8 ng/L [25, 27,28]. The elimination rate (%) of the neonicotinoid insecticides in WWTP was determined with the next equation 1:…”

“…In some studies, carried out by INCD ECOIND in 2018, the presence and behavior of neonicotinoids in wastewater and in surface water taken from the Bucharest WWTP, was evaluated [25,27,28]. Composite samples were taken from the treatment plant in Bucharest in November 22-26, 2017, from influent, decanted and effluent.…”

Neurotoxic Effects of Neonicotinoids on Mammals: What Is There beyond the Activation of Nicotinic Acetylcholine Receptors?—A Systematic Review

“…Thus, humans are continuously exposed to these pesticides, which can be absorbed through food or drinking water, by inhalation or dermal contact with occupational spray by-products, as well as by indoor air contamination following termite or pet pest control treatments [4,16]. In line with this, residues of NNs have been detected in a wide variety of foods and surface waters, which can pose a serious health problem for the animals and humans that consume them [16][17][18][19][20][21][22][23][24][25][26].…”

Dietary Contamination With Neonicotinoid (Clothianidin) Gradient Triggers Specific Dysbiosis Signatures of Microbiota Activity Along the Honeybee (Apis Mellifera) Digestive Tract

“…neonicotinoids [3]. Being soluble in water and persisting into the environment [4,5], neonicotinoids are mainly bioaccumulated in honeybees via pollen and water intake [6]. Neonicotinoids were found on honeybee body [7] and inside the honeybee, more speci cally within gut cells [8].…”