Environmental risk assessment of selected organic chemicals based on TOC test and QSAR estimation models

Environmental risks of organic chemicals have been greatly determined by their persistence,bioaccumulation, and toxicity（PBT） and physicochemical properties. Major regulations in different countries and regions identify chemicals according to their bioconcentration factor（BCF） and octanol–water partition coefficient（Kow）, which frequently displays a substantial correlation with the sediment sorption coefficient（Koc）. Half-life or degradability is crucial for the persistence evaluation of chemicals. Quantitative structure activity relationship（QSAR） estimation models are indispensable for predicting environmental fate and health effects in the absence of field-or laboratory-based data. In this study, 39 chemicals of high concern were chosen for half-life testing based on total organic carbon（TOC） degradation,and two widely accepted and highly used QSAR estimation models（i.e., EPI Suite and PBT Profiler） were adopted for environmental risk evaluation. The experimental results and estimated data, as well as the two model-based results were compared, based on the water solubility, Kow, Koc, BCF and half-life. Environmental risk assessment of the selected compounds was achieved by combining experimental data and estimation models. It was concluded that both EPI Suite and PBT Profiler were fairly accurate in measuring the physicochemical properties and degradation half-lives for water, soil, and sediment.However, the half-lives between the experimental and the estimated results were still not absolutely consistent. This suggests deficiencies of the prediction models in some ways, and the necessity to combine the experimental data and predicted results for the evaluation of environmental fate and risks of pollutants.

In situ combined chemical and biological assessment of estrogenic pollution in a water recycling system

Estrogenic pollution and its control in aquatic systems have drawn substantial attention around the world. The chemical and biological assessment approaches currently utilized in the laboratory or field cannot give an integrated assessment of the pollution when used separately. In this study, in situ chemical and biological methods were combined to detect pollution in a water recycling system. Data for the water quality index（WQI） demonstrated that the water treatment resulted in the decline of pollution from upstream to downstream.Wild male Nile tilapia, Oreochromis niloticus, was sampled in June and September. The concentrations of four common endocrine disrupting chemicals（EDCs） were determined in the tilapia liver by chromatographic analysis methods. The level of 17β-estradiol（E2） declined from upstream to downstream in both months. In contrast, the levels of bisphenol A（BPA）,di-（2-ethylhcxyl） phthalate（DEHP）, and perfluorooctane sulfonate（PFOS） did not display this declining tendency. The highest relative expression of vitellogenin 1（VTG1） was observed in tilapia from upstream, then the level significantly decreased along the water system. The relative expression levels of CYP1A1 in the water system were also significantly higher than that of the control. However, no declining trend could be observed along the water system. The change of VTG1 expression corresponded well with that of E2 levels in the tilapia liver. Overall,our study assessed the pollution by endocrine disruptors using chemical and biological data with good correspondence. This study also demonstrated the effectiveness of the water recycling system in eliminating estrogen pollution in municipal sewage.

Epithelial-mesenchymal transition effect of fine particulate matter from the Yangtze River Delta region in China on human bronchial epithelial cells

Epidemiological studies have demonstrated that fine particulate matter（PM（2.5）） exposure causes airway inflammation, which may lead to lung cancer. The activation of epithelial–mesenchymal transition（EMT） is assumed to be a crucial step in lung tumor metastasis and development. We assessed the EMT effect of low concentrations（0, 0.1, 1.0, and 5.0 μg/m L）of PM（2.5） organic extract on a human bronchial epithelial cell line（BEAS-2 B）. PM（2.5） samples were collected from three cities（Shanghai, Ningbo, and Nanjing） in the Yangtze River Delta（YRD） region in autumn 2014. BEAS-2 B cells were exposed to the PM（2.5） extract to assess cell viability, invasion ability as well as the relative m RNA and protein expressions of EMT markers. Our findings revealed that BEAS-2 B cells changed from the epithelial to mesenchymal phenotype after exposure. In all groups, PM（2.5） exposure dose-dependently decreased the expression of E-cadherin and increased the expression of Vimentin. The key transcription factors, including ZEB1 and Slug, were significantly up-regulated upon exposure. These results indicated that the PM（2.5） organic extract induced different degrees of EMT progression in BEAS-2 B cells. The cell invasion ability increased in a concentration-dependent manner after 48 hr of treatment with the extract. This study offers a novel insight into the effects of PM（2.5） on EMT and the potential health risks associated with PM（2.5） in the YRD region.