Field evaluation of diffusive gradients in thin-film passive samplers for wastewater-based epidemiology.

There is a need for a simple water sampling technique to enable routine monitoring of community drug consumption through wastewater-based epidemiology (WBE). This study investigates the potential use of diffusive gradients in thin films to sample organic compounds (o-DGT) for WBE. Three types of resin gels (HLB, XAD 18, and XDA-1) within o-DGT samplers each were deployed in triplicate at the inlets of two sewage treatment plants of Southern Asian cities. The target compounds included 15 illicit drugs and 18 antibiotics. A comprehensive evaluation was undertaken regarding each resin's ability to accumulate the target compounds and accuracy by comparing active samples. The organic compounds accumulated on each resin gel were characterised at the molecular level using Fourier transform ion-cyclotron-resonance mass spectrometry (FT-ICR MS). The results showed that the HLB resin performed better than the XAD 18 and XDA-1 resins. Based on calculations using the HLB-DGT data, methamphetamine and heroin were the two most popular illicit drugs consumed among the studied populations, and were followed by ketamine and codeine, which agreed well with the authoritative reports and reference data. The total drug consumption in Hanoi was one order of magnitude higher than that in Guangzhou, thus implying a probably more serious drug situation in the former. Overall, the findings of this study demonstrate that o-DGT passive samplers are a promising tool for WBE studies, particularly at WWTPs or in urban streams where an automatic sampler for taking composite water samples is absent.

Occurrence of N-Nitrosamines in the Pearl River delta of China: Characterization and evaluation of different sources.

N-nitrosamines in water have drawn significant concerns for the health of water consumers due to their carcinogenic properties. N-nitrosamines are formed during disinfection of wastewater as well as different industrial and agricultural processes. This study characterized the N-nitrosamines compositions in eleven different wastewaters in the Pearl River Delta (PRD) in Southeast China, and the spatial distributions and the abundances of N-nitrosamines in the Pearl River water were detected. The results indicated that five N-nitrosamines species, including N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosopyrrolidine (NPYR), N-nitrosomorpholine (NMOR) and N-nitrosodibutylamine (NDBA) were found in the industrial wastewater samples in the PRD. Remarkably high concentrations of NDMA (up to 4000 ng/L) were found in the wastewaters from the textile printing and dyeing as well as the electroplating, whereas NDMA, NDEA and NMOR were detected in the domestic wastewaters at concentrations lower than 15 ng/L. Moreover, we found that certain treatment processes for the electroplating wastewater could form a significant amount of NDMA, NPYR and NMOR. Analyses of the Pearl River water samples showed occurrences of different N-nitrosamines species, including NDMA (5.7 ng/L), NDEA (1.7 ng/L), NPYR (2.2 ng/L), NMOR (2.2 ng/L) and NDBA (4.9 ng/L). The abundances of N-nitrosamines species varied spatially due to the inputs from the different sources. Thus, our study provides unique and valuable information for occurrences, abundances and source characteristics of N-nitrosamines in the PRD.

Inflammation Response of Water-Soluble Fractions in Atmospheric Fine Particulates: A Seasonal Observation in 10 Large Chinese Cities.

Spatiotemporal trends in pro-inflammatory (interleukin (IL)-6 and IL-8) release after exposure to the water-soluble fractions of PM2.5 sampled in 10 large Chinese cities over 1 year were investigated. Chemical components (water-soluble ions, metal(loid) elements, water-soluble organic carbon (WSOC), humic-like substances (HULIS), and endotoxins) in PM2.5 samples were measured, and the molecular structure of WSOC was also analyzed by nuclear magnetic resonance. Changes in DNA methylation and gene expression of candidate genes were also evaluated to explore the potential mechanisms. PM2.5 from southern cities induced lower pro-inflammatory responses compared to those from northern cities. Seasonal differences in toxicity were noted among the cities. IL-6 was significantly correlated with HULIS (as the main fraction of WSOC with oxygenated carbohydrate structures characteristic), Pb, and endotoxin. Furthermore, DNA methylation and gene expression changes in RASSF2 and CYP1B1 were related to pro-inflammatory secretion. Certain components of PM2.5, rather than PM2.5 mass itself, determine the pro-inflammatory release. In particular, HULIS, which originated from primary biomass burning and residual coal combustion, and secondary organic aerosols, appear to be the key component in PM2.5 to induce human health risk.

Cordycepin Downregulates Cdk-2 to Interfere with Cell Cycle and Increases Apoptosis by Generating ROS in Cervical Cancer Cells: in vitro and in silico Study.

BACKGROUND: Cordycepin is a small molecule from medicinal mushroom Cordyceps, which has been reported for anticancer properties. OBJECTIVE: In this study, we have focused on the investigation of cordycepin effect on cervical cancer cells with further clarification of possible molecular mechanism. METHOD: We have used cell viability and cell counting assay for cytotoxic effect of cordycepin, flow cytometric assay of apoptosis and cell cycle, and quantitative PCR (qPCR) and Western blotting for the determination of target gene expression. Molecular docking and Molecular dynamics simulation were used for in silico analysis of cordycepin affinity to target protein(s). RESULTS: Treatment of cordycepin controlled SiHa and HeLa cervical cancer cell growth, increased the rate of their apoptosis, and interfered with cell cycle, specifically elongated S-phase. qPCR results indicated that there was a downregulation of cell cycle proteins CDK-2, CYCLIN-A2 and CYCLIN-E1 in mRNA level by cordycepin treatment but no significant change was observed in pro-apoptotic or antiapoptotic proteins. The intracellular reactive oxygen species (ROS) level in cordycepin treated cells was increased significantly, implying that apoptosis might be induced by ROS. Western blot analysis confirmed significant decrease of Cdk-2 and mild decrease of Cyclin-E1 and Cyclin-A2 by cordycepin, which might be responsible for regulating cell cycle. Molecular docking indicated high binding affinity of cordycepin against Cdk-2. Molecular dynamics simulation further confirmed that the docked pose of cordycepin-Cdk-2 complex remained within the binding pocket for 10 ns. CONCLUSION: Our study suggests that cordycepin is effective against cervical cancer cells, and regulating cell cycle via cell cycle proteins, especially downregulating Cdk-2, and inducing apoptosis by generating ROS are among the mechanisms of anticancer activities of cordycepin.

Microbial degradation of fomesafen and detoxification of fomesafen-contaminated soil by the newly isolated strain Bacillus sp. FE-1 via a proposed biochemical degradation pathway.

Fomesafen is a long residual herbicide and poses a potential risk to environmental safety, leading to an increasing need to find eco-friendly and cost-effective techniques to remediate fomesafen-contaminated soils. In this article, a novel strain of Bacillus sp., FE-1 was isolated from paddy field soil. This strain was found to degrade fomesafen both in liquid medium and in soil. >82.9% of fomesafen, at concentrations of 0.5, 1 and 10mgL-1, was degraded by Bacillus sp. FE-1 in liquid medium within 14h. The optimal pH and temperature for degradation were 7.0 and 35°C, respectively. Soil samples inoculated with strain FE-1 showed significantly increased rates of fomesafen degradation. Two metabolites of fomesafen degradation were detected and identified as amino-fomesafen and 5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-amino-benzoic acid. This is the first report of a novel fomesafen biodegradation pathway involving the reduction of a nitro group followed by the hydrolysis of an amide bond. The excellent remediation capability of the isolate FE-1 to detoxify fomesafen-contaminated soil was shown by bioassay of the sensitive aftercrop corn. The results indicate that Bacillus sp. FE-1 has potential for use in the bioremediation of fomesafen-contaminated soil.

Effects of aging process on adsorption-desorption and bioavailability of fomesafen in an agricultural soil amended with rice hull biochar.

Biochar has been introduced as an acceptable soil amendment due to its environmental benefits such as sequestering soil contaminants. However, the aging process in biochar amended soil probably decreases the adsorption capacity of biochar through changing its physico-chemical properties. Adsorption, leaching and bioavailability of fomesafen to corn in a Chinese soil amended by rice hull biochar after 0, 30, 90 and 180days were investigated. Results showed that the addition of 0.5%-2% fresh biochar significantly increases the adsorption of fomesafen 4-26 times compare to unamended soil due to higher SSA of biochar. Biochar amendment also decreases fomesafen concentration in soil pore water by 5%-23% resulting lower risk of the herbicide for cultivated plants. However, the aging process decreased the adsorption capacity of biochar since the adsorption coefficient values which was 1.9-12.4 in 0.5%-2% fresh biochar amended soil, declined to 1.36-4.16, 1.13-2.78 and 0.95-2.31 in 1, 3 and 6-month aged treatments, respectively. Consequently, higher desorption, leaching and bioavailable fraction of fomesafen belonged to 6-month aged treatment. Nevertheless, rice hull biochar was effective for sequestering fomesafen as the adsorption capacity of biochar amended soil after 6months of aging was still 2.5-5 times higher compared to that of unamended soil.

Reduced mobility of fomesafen through enhanced adsorption in biochar-amended soil.

The residual soil material resulting from biomass thermochemical transformation during carbon separation, known as biochar, has been introduced as a soil amendment because of its numerous environmental benefits, including uses for contaminated land management. Adsorption and leaching of fomesafen in soils amended with 3 different rates of rice hull biochar (0.5%, 1%, and 2% w/w) under laboratory conditions were investigated, and studies were performed following a batch equilibration adsorption-desorption procedure and a column experiment for leaching. Adsorption-desorption data fit with the Freundlich equation well. The adsorption coefficient of fomesafen sharply increased from 0.59 to 0.99 to 8.02 to 22.23 when the amount of biochar amendment in the soil increased from 0% to 2% (w/w). In addition, a strong correlation was found between the amount of adsorbed fomesafen and the rate of amended biochar (r > 0.992, p < 0.01). Furthermore, biochar amendments reduced the desorption percentage of fomesafen in the soils. The outcomes of the leaching experiment also illustrated that the lowest fomesafen concentration in the leachate (21.4%) occurred in the soil amended with 2% (w/w) biochar. Moreover, the adsorption coefficients (K(f)(ads)) of the soil were positively correlated with the total amount of adsorbed fomesafen in the corresponding soil columns (r = 0.990, p < 0.01) and negatively correlated with the leachate percentage (r = 0.987, p < 0.05). The results of the present study suggest that biochar amendments in agricultural soils likely alter the fate of herbicides by decreasing their transport through enhanced adsorption.

Soil genotoxicity induced by successive applications of chlorothalonil under greenhouse conditions.

Greenhouse production of vegetables has been developed rapidly in China. High temperature and humidity inside the greenhouse make this environment more suitable for fast reproduction of fungal diseases. Fungicides are among the chemicals used extensively in the greenhouse to prevent crops from invasive infections by phytopathogens; however, little is known about the accumulation of fungicides in soil and their effect on soil quality under greenhouse conditions. In the present study, the accumulation of the fungicide chlorothalonil (CT) and its toxic metabolite hydroxy-chlorothalonil (HCT) in soil as well as their related soil genotoxicity under greenhouse conditions was investigated. The results indicated that both CT and HCT accumulated in soil with repeated applications of CT, and the accumulation level was strongly correlated to application dosage and its frequency. In addition, soil genotoxicity, which was measured by Vicia faba, also increased with the accumulation of CT and HCT, and the main contributor to this phenomenon was CT rather than HCT. The data demonstrated that successive applications of fungicides may result in their accumulation in soil and thus a decline in soil quality.