Presence and risk assessment of pharmaceutically active compounds in neotropical small basins, Brazil

Abstract

Pharmaceutically active compounds (PAC) are micropollutants that represent emerging contaminants (ECs) commonly found in aquatic environments. Exposure of aquatic biota to these identified ECs has resulted in severe effects. In the last few years, the number of studies on PAC has grown quickly owing to increasing awareness of the potential environmental and health risks related to these micropollutants. The aim of our study was to evaluate the contamination levels of selected PAC and their potential ecological threat to forested streams. Samples of stream water were collected in the second largest city in Mato Grosso do Sul State in center-west of Brazil. Physicochemical parameters and concentrations of PAC were quantified in samples collected in six field campaigns. Ecological risk assessment (ERA) based on risk quotient (RQ) was carried out based on the maximum measured concentration of PAC in water. Six pharmaceutical compounds were successfully quantified in the forested streams, namely caffeine (1.0 – 1,696.04 ng/L), naproxen (0.9 – 681.80 ng/L), diclofenac (0.8 – 849.94 ng/L), estriol (0.9 – 13.22 ng/L), estradiol (0.9 – 587.30 ng/L) and ethinylestradiol (0.9 – 790.90 ng/L). From an ecological risk perspective, ethinylestradiol, estradiol, diclofenac and caffeine can be considered as priority PAC because they showed moderate to high risks to aquatic organisms and may further lead to damages along the food chain. This study provides valuable information to reinforce the importance of continuous monitoring of the forested streams in center-west region of the country, as well as efforts to control the entry of these micropollutants in watercourse.