Bioconcentration of carbamazepine, enalapril, and sildenafil in neotropical fish species

ROJO, M.; CRISTOS, D.S.; CARRIQUIRIBORDE, P.

Frontiers in Toxicology

Frontiers Media SA

Año: 2024 vol. 5

Sewage effluents are the main source of entry of Human Pharmaceutical ActiveIngredients (HPAIs) to surface water bodies. Carbamazepine (CBZ), psychiatric drug,enalapril (ENA) antihypertensive, and sildenafil (SIL), to treat erectile dysfunction,have been frequently detected in receiving wastewater and in wild fish species fromArgentina. This study aimed to assess the bioconcentration of selected HPAIs innative fish species of the Del Plata Basin. In the first trial, the bioconcentration factorsof CBZ, ENA, and SIL were obtained by exposing Cnesterodon decemmaculatus,respectively, to 135, 309, and 70 μg/L during 96 h. Then the bioconcentrationkinetic of SIL was comparatively assessed in C. decemmaculatus and Piaractusmesopotamicus exposed, respectively, to 44.1 and 16.2 μg/L during a one-week,followed by a four-day depuration phase. HPAIs concentrations in water andtissue were measured by HPLC-MS after 0.22 μm filtration and directinjection or solid-liquid extraction, respectively. Bioconcentration factorsobtained empirically (BCFe) for C. decemmaculatus were CBZ = 1.5, SIL = 1.4,and ENA = 0.007. Parameters estimated by the SIL bioconcentration kinetic modelfor C. decemmaculatus were: uptake rate constant (k1) = 5.5 L/kg d, elimination rateconstant during uptake phase (k2u) = 0.00175 d−1, maximum predicted tissueconcentration (Ct(max)) = 138588 μg/kg, estimated bioconcentration factor(BCFm) = 3143, lag time between the exposure and the first detection in tissue(tlag) = 0 d, elimination rate constant in the depuration phase (k2d) = 0.49 d−1 andhalf-life in the tissue (t1/2) = 1.4 d. The model parameters for P.mesopotamicus werek1: 7.3 L/kg d, k2u: 0.0836 d−1, Ct(max): 1423 μg/kg, BCFm: 88, tlag: 3.8 d in the uptakephase and k2d: 0.31 d−1 and t1/2: 2.3 d in the depuration phase. The reachedconclusions were: 1) the bioconcentration capacity of CBZ and SIL are similarbut around 200 times higher than ENA, 2) the time to reach the bioconcentrationequilibrium for SIL is longer than 1 week, then estimated BCFm are between 1 and 3orders of magnitude higher than BCFe obtained after 96 h exposure, but actualvalues need to be verified, 3) substantial differences (≈30 fold) were observed in theestimated BCF of SIL among species, indicating the need for further studies towardunderstanding such diversity to improve HPAIs ecological risk assessmentworldwide.