Concentration and risk of pharmaceuticals in freshwater systems are related to the population density and the livestock units in Iberian Rivers

Abstract

Considerable amounts of pharmaceuticals are used in human and veterinary medicine, which are not efficiently removed during wastewater and slurries treatment and subsequently entering continuously into freshwater systems. The intrinsic biological activity of these non-regulated pollutants turns their presence in the aquatic environment into an ecological matter of concern. We present the first quantitative study relating the presence of pharmaceuticals and their predicted ecotoxicological effects with human population and livestock units. Four representative Iberian River basins (Spain) were studied: Llobregat, Ebro, Júcar and Guadalquivir. The levels of pharmaceuticals were determined in surface water and sediment samples collected from 77 locations along their stream networks. Predicted total toxic units to algae, Daphnia and fish were estimated for pharmaceuticals detected in surface waters. The use of chemometrics enabled the study of pharmaceuticals for: their spatial distribution along the rivers in two consecutive years; their potential ecotoxicological risk to aquatic organisms; and the relationships among their occurrence and predicted ecotoxicity with human population and animal farming pressure. The Llobregat and the Ebro River basins were characterized as the most polluted and at highest ecotoxicological risk, followed by Júcar and Guadalquivir. No significant acute risks of pharmaceuticals to aquatic organisms were observed. However potential chronic ecotoxicological effects on algae could be expected at two hot spots of pharmaceuticals pollution identified in the Llobregat and Ebro basins. Analgesics/antiinflammatories, antibiotics and diuretics were the most relevant therapeutic groups across the four river basins. Among them, hydrochlorothiazide and gemfibrozil, as well as azithromycin and ibuprofen were widely spread and concentrated pharmaceuticals in surface waters and sediments, respectively. Regarding their predicted ecotoxicity, sertraline, gemfibrozil and loratidine were identified as the more concerning compounds. Significantly positive relationships were found among levels of pharmaceuticals and toxic units and population density and livestock units in both surface water and sediment matrices.

The use of juvenile Solea solea as sentinel in the marine platform of the Ebre Delta: in vitro interaction of emerging contaminants with the liver detoxification system

“…Recent in vivo and in vitro studies with PPCPs have indicated that CbE activity can be modulated by a broad range of chemicals as it participates in its metabolism and detoxification reactions and can also be inhibited in vitro by lipid regulators as it occurs in humans (Ribalta et al 2015;Solé et al 2014;Solé and Sanchez-Hernandez 2015). Many of these chemicals are found in the watercourse of the Ebre river (Lopez-Serna et al 2012;Osorio et al 2016). Although the individual levels detected are not likely to be responsible for the significant inhibition observed, the consequences derived from cocktail mixtures are not known.…”

“…Thus, important phase I reactions involved in xenobiotic metabolism-EROD, BFCOD and CbE activities-were screened for the potential interaction of PPCPs of environmental concern that can be found in the river basin (Fabrega et al 2013;Osorio et al 2016).…”

Occurrence, Distribution, and Risk Assessment of Antibiotics in a Subtropical River-Reservoir System

“…These results further suggest that the reservoir may have a potency to regulate the migration and transformation of antibiotics. On the other hand, compared to the pristine reservoir, it also implies that the concentration and distribution of antibiotics in the aquatic environment may be more related to human activities [56]. …”

Estudio piloto de la toxicidad de los sedimentos del río Pasto en el tramo La Playita-Puente La Carolina, asociada al uso de pesticidas

“…En este orden de ideas, la mala calidad del agua de un río, puede estar asociada a diversos factores de origen antrópico o natural, por ejemplo: escorrentías de zonas agrícolas o pecuarias, el vertimiento de aguas residuales domésticas o industriales o por arrastre de material sólido asociado a eventos climáticos [4] En consecuencia, para estudiar la contaminación de los ríos, se debe considerar las sustancias contaminantes presentes en el agua y los sedimentos, así como los fenómenos de transferencia entre ambas matrices; pues los sedimentos reconcentran sustancias con el transcurso del tiempo, ya que su concentración en el agua es más variable y dinámica [5]- [7] Además, los sedimentos albergan organismos de la cadena trófica que pueden verse afectados por sustancias orgánicas complejas entre las cuales se encuentran ciertos compuestos orgánicos persistentes (COPs) o sus metabolitos que pueden ser tóxicos; por ejemplo: ciertos plaguicidas, compuestos farmacéuticos o retardantes de llama [6]- [10]Así mismo, muchos COPs son altamente hidrofóbicos por lo que su nocividad se debe rastrear en los sedimentos y/o en la biota [8], [11], [12].…”

“…A este respecto, la literatura técnica señala entre otros aspectos, que ciertos COPs como los hidrocarburos aromáticos policíclicos (PAHs), los plaguicidas o los fármacos; y los metales pesados, tienden a fijarse y movilizarse a través de los sedimentos de un río. Asimismo, existe una estrecha relación entre los eventos climáticos y el transporte, destino y transformación de tales sustancias en un río [8], [10], [11] En este contexto, por ejemplo, bajo eventos de lluvias o sequias intensas, los sedimentos pueden transportan contaminantes hacia y desde zonas inundadas o a zonas aguas abajo del río, alejadas de las descargas puntuales. Así, mismo pueden ocurrir diferentes fenómenos de transferencia de masa entre las matrices agua y sedimentos, por ejemplo, aquellos fenómenos relacionados con las características granulométricas de los sedimentos o a las propiedades fisicoquímicas tanto del agua como de los sedientos [8], [13], [14].…”