Presence of pesticides in fish species of commercial importance in the southern coastal fringe of the Río de la Plata

VATTIATO M; CAPELLETTI N; PARACAMPO, A.; MAIZTEGUI, T.; FANELLI S.L.; LAVARIAS S; BONETTO C; MUGNI H

Buenos Aires

Congreso; e Litoral 10th Latin American Pesticide Residue Workshop:; 2025

Universidad Nacional del Litoral

The intensive use of pesticides in Argentina has caused their presence instreams draining agricultural areas, but their impact on the Río de la Plata,which receives these tributaries, remains largely unreported. The aim ofthe present study was to assess the eventual presence of pesticides infishes on the southern coastal fringe. It was hypothesized that contaminantloads to the river would result in the presence of pesticides in fish muscles.Three species used for human consumption and different feeding habitswere studied: Prochilodus lineatus (sábalo) iliophagous-detritivorous;Odontesthes bonariensis (pejerrey) zooplanktophagous and Micropogoniasfurnieri (corvina) benthophagous. The concentrations of chlorpyrifos,endosulfan (I, II and sulfate), lambda cyhalothrin, permethrin, cypermethrin,and deltamethrin were determined in the dorsal muscle (wet weight) of fishby gas chromatography (GC-ECD). Pesticides were detected in 24 of the 36specimens analyzed (67%). The average of total pesticide concentration insábalo (14.3 ng/g ww) was significantly higher than in pejerrey (0.17 ng/g ww)and corvina (0.43 ng/g ww). The total concentration of insecticide in sábalowas positively correlated (r=0,55; p =0.028) with the % of total lipids. Theaverage lipid content in sábalo (4.9%) was significantly higher than pejerrey(0.13%) and corvina rubia (0.36%). The most frequently detected pesticideswere endosulfan sulfate and chlorpyrifos (53% and 47% respectively).The concentrations of these compounds ranged from 0.1 to 9.6 ng/g ww(endosulfan) and 0.1 to 410.8 ng/g ww (chlorpyrifos). Pyrethroids weredetected less frequently, 10% and ranged from 0.2 to 10.9 ng/g ww. Presentresults confirm the presence of pesticides in fishes from the Rio de la Platacoastal fringe. The differences between species are influenced by severalfactors, including their feeding habits, the chemical properties of pesticides(hydrophobicity), and their lipid content. In consideration of the risk factors,we estimated the Minimal Risk Levels (MRLs) as a prediction of how muchsomeone can be exposed to a chemical without detectable health risks. 17%of the samples, mainly sábalo and pejerrey, exceed the MRLs for chlorpyrifos,endosulfan, and deltamethrin. These results are concerning as these speciesserve as an important food source for recreational and artisanal fisheriesalong the southern coastal fringe of the Río de la Plata.