This manuscript reports a 3-year study on occurrence of pharmaceuticals, hormones, and triclosan in surface waters of a central urban region of São Paulo State of Southeast Brazil (the Monjolinho River in São Carlos). Water samples collected once at every 2 months were pre-concentrated by solid-phase extraction (SPE) and analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The most frequently detected compounds in higher concentrations were caffeine, paracetamol, and atenolol (maximum concentrations 129,585, 30,421, and 8199 ng L(-1), respectively), while hormones estrone and 17-β-estradiol were the least detected, in levels up to 14.8 ng L(-1). There was an increasing trend in concentrations of most of the compounds along the river course, especially downstream of the river where there is discharge of both wastewater treatment plant effluent and raw sewage from a particular region of São Carlos city. Concentrations of contaminants were higher during dry periods as a result of decline in the water levels. Decrease in concentrations near the river mouth occurred to different extents for each compound. It was high for caffeine and atenolol, but was very low for carbamazepine and diclofenac. The present study reports the first data about the occurrence of some major emerging contaminants in the Monjolinho River. Besides its regional significance, this work may assist in composing a dataset for water contamination diagnosis focusing on emerging contaminants, both in the Brazilian as well as in the Global studies related to aquatic ecosystems. Such datasets can be helpful for making future public policies on water quality, since these compounds are not yet legally regulated.

No abstract

No abstract

No abstract

Freshwater resources are increasingly scarce due to human activities, and the understanding of water quality variations at different spatial and temporal scales is necessary for adequate management. Here, we analyze the hypotheses that (1) the presence of a wastewater treatment plant (WWTP) and (2) a polluted tributary that drains downstream from the WWTP change the spatial patterns of physicochemical variables (pH, turbidity, dissolved oxygen, and electrical conductivity) and nutrient concentrations (reactive soluble phosphorus, total phosphorus, nitrogen series, total nitrogen, and total dissolved carbon) along a mid-order river in SE Brazil and that these effects depend on rainfall regime. Six study sites were sampled along almost 4 years to evaluate the impacts of human activities, including sites upstream (1-3) and downstream (5-6) from the WWTP. The impacts were observed presenting an increasing trend from the source (site 1) towards Água Quente stream (site 4, the polluted tributary), with signs of attenuation at site 5 (downstream from both WWTP and site 4) and the river mouth (site 6). Input of nutrients by rural and urban runoff was observed mainly at sites 2 and 3, respectively. At sites 4 and 5, the inputs of both untreated and treated wastewaters increased nutrient concentrations and changed physicochemical variables, with significant impacts to Monjolinho River. Seasonal variations in the measured values were also observed, in agreement with the pluviometric indexes of the region. Univariate analyses suggested no effect of the WWTP for most variables, with continued impacts at sites downstream, but non-parametric multivariate analysis indicated that these sites were recovering to chemical characteristics similar to upstream sites, apparently due to autodepuration. Therefore, multivariate methods that allow rigorous tests of multifactor hypotheses can greatly contribute to determine effects of both point and non-point sources in river systems, thus contributing to freshwater monitoring and management.