No abstract

Recently, chlorination disinfection technology applying ultraviolet radiation (Cl/UV) has received attention as an advanced oxidative process (AOP) for the generation of highly oxidant species. Many studies have evaluated its effects on pathogen inactivation, contaminant removal, and formation of disinfection by-products (DBPs). However, the degradation of three endocrine disruptor chemicals (EDCs), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), and bisphenol-A (BPA), associated with simultaneous disinfection and estrogenic activity and ecotoxicity assessments has not yet been reported. Compound degradation increased with increasing chlorine concentrations (2 mg·L-1 chlorine), with pseudo-first-order kinetics 1.86×10−2 s-1, 3.06×10−2 s-1, and 3.09×10−2 s-1 for BPA, E2, and EE2, respectively. The degradation kinetics in a WWTP effluent significantly decreased to 4.94×10−2 min-1, 4.75×10−2 min-1, and 4.84×10−2 min-1, for BPA, E2, and EE2, respectively. However, 45% TOC removal and disinfection of E. coli and total coliform bacteria (TCB) were observed in 10 min of treatment. The yeast estrogen screen (YES) revealed that the treatment did not form by-products with estrogenic activity, demonstrating cleavage or mineralization in the phenolic group, common to all assessed compounds. High cell growth inhibition and mortality for Raphidocelis subcapitata and Ceriodaphnia dubia, respectively, were observed during the photodegradation process. Thus, the formed DBPs may be responsible for the observed toxicity and should be taken into account in WWTP treatments in order to monitor the formation of chlorinated by-products.

Studies assessing the presence of endocrine disrupting compounds in marine environments have increased in the last decades. In Brazil, the combination of poor sanitation conditions and low investment in sewage treatment plants leads to significant contamination of receiving waters. The risks of these micropollutants in the aquatic biota include biochemical and histopathological alterations of the liver, gonads, and kidneys, as well as, reproductive process and development modifications, and behavioral changes, among others. The aim of this study was to evaluate the quality of the surface and deep waters of Guanabara Bay, southeastern Brazil, regarding the presence of estrogenic substances. Acute toxicity assays were also conducted employing Vibrio fischeri. The estrogenic activity of the water samples was determined by Yeast Estrogen Screen assay and the quantification of the Bisphenol A, estriol, 17β-estradiol, and 17α-ethinylestradiol by high-performance liquid chromatography, using fluorescence and diode array detectors. Estrogenic activity ranged from 9 to 77 ng L-1 of estradiol equivalents. The highest micropollutants concentrations were detected for bisphenol A (298.5 and 465.5 ng L-1), followed by 17α-ethinylestradiol (248 and 256.9 ng L-1), estriol (70.7 and 179.6 ng L-1), and 17β-estradiol (167 and 174.8 ng L-1) for surface and deep waters, respectively. The findings indicate significant risks for the Guanabara Bay ecosystem. No acute toxicity effects were observed in the V. fisheri assay. These data reflect the current environmental degradation situation of the bay’s waters and highlight the need for the systematic monitoring of this important estuary.

There is increasing concern in the scientific community regarding emerging contaminants in aquatic matrices because of the potential effects of these contaminants on aquatic biota. In recent decades, the Itaipu–Piratininga lagoon system has suffered a series of environmental impacts, among which water pollution stands out. In this context, the aim of this study was to analyse the occurrence of pharmaceuticals and endocrine disrupters in water (dissolved and particulate phases) and in surface sediments, and their potential oestrogenic effects. Contaminant concentrations were determined by gas chromatography–mass spectrometry, whereas oestrogenic activity was evaluated using the yeast oestrogen screen assay. Of the 12 compounds analysed, concentrations of gemfibrozil, acetaminophen and diclofenac were below the limit of detection. The compounds with the highest detection frequency in the water were bisphenol A>4-octylphenol>naproxen>oestradiol, whereas in the sediment were bisphenol A>naproxen>oestradiol. Higher pharmaceutical concentrations and numbers of microcontaminants were observed in August 2017 (winter), which can be explained by the lower dilution and degradation capacity of these compounds during winter. Oestrogenic activity was observed in at least one of the three matrices (i.e. water (dissolved and particulate phases) and surface sediments) at all sampling stations and in both sampling campaigns (January and August 2017). Combined with data in the literature data, the results of this study indicate probable adverse effects of contaminants on aquatic organisms of this lagoon system.

This study aimed to determine endocrine disruptors in urbanized rivers Maracanã and Mangue Channel in Rio de Janeiro the second most populated city in Brazil. Bisphenol A, 17β-estradiol, estriol, and 17α-ethinylestradiol were determined by high-performance liquid chromatography with a diode array detector and fluorescence detector In addition, the evaluation of estrogenic activity was performed by the YES bioassay (Yeast estrogen screen) with the Saccharomyces cerevisiae yeast, and acute toxicity assays were performed using Daphnia similis and Vibrio fischeri. Estrogenic activity in the water samples ranged from below the limit of detection (<LD) to 1.6 ng L-1, while bisphenol A ranged from 22.3 to 1325.2 ng L-1 and estrogens 17β-estradiol from <LD to 55.2 ng L-1, estriol from <LD to 313.7 ng L-1 and 17α-ethinylestradiol, from <LD to 409.4 ng L-1. The acute toxicity was not detected in both analyzed organisms. The present study indicates a serious level of pollution by the compounds evaluated with significant risks to the aquatic ecosystem, mainly for Guanabara Bay which receives urbanized river discharge. Therefore, recommending the need for systematic monitoring and mitigating actions in these water bodies.