Effect of acute exposure to PFOA on mouse liver cells in vivo and in vitro

Increasingly, epidemiological evidences indicate chemosynthetic perfluorooctanoic acid (PFOA), an environmental pollutant, induces potential adverse effect on human health after long-term exposure. However, less study has been performed for assessment of acute effect of PFOA exposure on metabolic homeostasis. In experimental designs, PFOA-exposed liver cells in vivo and in vitro were used to discuss underlying mechanism related to PFOA-induced metabolic dysfunction. In serological tests, PFOA-exposed mice showed increased treads of liver functional enzymes in alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin (T-BIL), trypsinase, low density lipoprotein-cholesterol (LDL-C), and insulin, while blood glucose, high density lipoprotein-cholesterol (HDL-C), and glucagon levels were reduced. In histocytological observations, PFOA-exposed liver showed visible cytoplasmic vesicles, and intact pancreatic islets were observed in PFOA-exposed pancreas. Additionally, increased insulin-positive cells and reduced glucagon-positive cells were detected in PFOA-exposed islets. As shown in immunoassays, PFOA-exposed liver resulted in elevations of cluster of differentiation 36 (CD36)-labeled cells and CD36 protein. In mouse liver cell study, PFOA-exposed cells showed increased cell apoptotic count, and increased phosphorylated levels of Bcl-2 and Bad in the cells. Furthermore, PFOA-exposed liver cells exhibited elevations of CD36-labeled cells and CD36 protein. Taken together, the present data demonstrate that acute exposure to PFOA-impaired liver function is associated with inducting CD36 expression and apoptosis, as well as disrupting key hormones in the pancreas.     

Heavy metal pollution in sediments of the largest reservoir (Three Gorges Reservoir) in China: a review

The Three Gorges Dam in China is the world’s largest dam. Upon its completion in 2003, the Three Gorges Reservoir (TGR) became the largest reservoir in China and plays an important role in economic development and national drinking water safety. However, as a sink and source of heavy metals, there is a lack of continuous and comparative data on heavy metal pollution in sediments. This study reviewed all available literatures published on heavy metals in TGR sediments and further provided a comprehensive assessment of the pollution tendency of these heavy metals. The results showed that heavy metal concentrations in TGR sediments varied spatially and temporally. Temporal variations indicated that Hg in tributaries, as well as As, Cd, Cr, Cu, Ni, Pb, and Zn in the mainstream, exhibited a higher probability to exceed background values after the impoundment of TGR. Pollution assessments by contamination factor, geoaccumulation index, and potential ecological risk were similar. High Cd and Hg concentrations in both the mainstream and tributaries are a cause for much concern. However, sediment quality guidelines produced different results, as most previous studies adopted different sampling and measurement strategies. The data inconsistencies and lack of continuity regarding the reservoir confirm the need for a continuous monitoring network and the development of quality criteria relevant to the sediments of the TGR in the future.     

Preparation of La-modified magnetic composite for enhanced adsorptive removal of tetracycline

Environmental Science and Pollution Research - Composite adsorbents usually outperform single component adsorbents as they could combine the properties and advantages of each component. In this...     

Degradation of streptomycin in aquatic environment: kinetics,pathway, and antibacterial activity analysis

Environmental Science and Pollution Research - Streptomycin used in human and veterinary medicine is released into the environment mainly through excretions. As such, its elimination in water...     

Hexabromocyclododecanes in surface sediments and a sediment core from Rivers and Harbor in the northern Chinese city of Tianjin

In the present study, hexabromocyclododecanes (HBCDs) were investigated in the sediment from Haihe River (HR), Dagu Dainage Canal (DDC) and Tianjin Harbor (TH) at Bohai Bay using a total of 51 samples of surface sediments and a sediment core collected from May to September in 2010, and its diastereomer- and enantiomer-specific profiles were analyzed. The concentration of total HBCDs were generally high, with mean value and ranges of 31.0 and 1.35–634 ng g^?1 dw, respectively. The contamination followed the order of TH > DDC > HR. Higher levels (up to 634 ng g^?1 dw) occurred in the lower reach of HR and DDC located in an industrial area of Tianjin. This is the first time to report so high concentration of HBCDs in sediment in Southeast Asia. The γ-diastereomer dominated in most samples (44 out of 51), and this is in agreement with the diastereomer distribution pattern in industrial products, while α-HBCD was the dominant diastereomer in the other seven samples. However, only few samples exhibited γ-diastereomer ratio similar to that (75–89%) in technical products, indicating the inter-transformation and variable degradation of the different isomers. The high ratio of γ-diastereomer could be used as an indicator for fresh contamination input. Enantiomeric factors (EFs) of HBCD isomers in most of the samples were statistically different from technical products (p < 0.05), showing a trend of more easily enrichment of the (?)-HBCD-enantiomer compared to the (+)-HBCD-enantiomer. The δ- and ε-diastereomers were frequently detected but at low level. The HBCDs in the sediment core showed several peaks, and the greatest value occurred in 2005, when a plastic manufacture plant using HBCD was set up nearby.     

Acute and chronic toxicity of organophosphate monocrotophos to Daphnia magna

The acute and chronic toxicity of monocrotophos (MCP), the binary joint toxicity of MCP and bifenthrin (BF), and sodium dodecyl benzene sulfonate (SDBS) to Daphnia magna (D. magna) was evaluated. The 24 h-median effective concentration (24 h-EC₅₀) and 48 h-median lethal concentration (48 h-LC₅₀) of MCP towards D. magna were 161 and 388 μ g/L, respectively. In addition, the lowest-observed effective concentration (LOEC) and non-observed effective concentration (NOEC) of MCP to D. magna were 10 and 5 μ g/L, respectively. Furthermore, the chronic value (ChV) of MCP against D. magna was 7 μ g/L and the acute chronic ratio (ACR) was 55. The number of offspring per female and the intrinsic rate of natural increase (r) were identified as the parameters that were most sensitive to MCP. In addition, toxic unit (TU) analysis was employed to evaluate the joint toxicities. The calculated TU_mix values of binary equitoxic mixtures of MCP + BF and MCP + SDBS were 1.47 and 1.63, respectively, which suggests that both equitoxic mixtures exert a limited antagonistic effect. The results of this study revealed that the toxic threshold of MCP towards D. magna is higher than its reported highest residue (4 μ g/L) in the ordinary aquatic environment, and that concurrent exposure to BF or SDBS may exert a slight antagonistic effect.     

An interprovincial cooperative game model for air pollution control in China

The noncooperative air pollution reduction model (NCRM) that is currently adopted in China to manage air pollution reduction of each individual province has inherent drawbacks. In this paper, we propose a cooperative air pollution reduction game model (CRM) that consists of two parts: (1) an optimization model that calculates the optimal pollution reduction quantity for each participating province to meet the joint pollution reduction goal; and (2) a model that distribute the economic benefit of the cooperation (i.e., pollution reduction cost saving) among the provinces in the cooperation based on the Shapley value method. We applied the CRM to the case of SO₂ reduction in the Beijing–Tianjin–Hebei region in China. The results, based on the data from 2003–2009, show that cooperation helps lower the overall SO₂ pollution reduction cost from 4.58% to 11.29%. Distributed across the participating provinces, such a cost saving from interprovincial cooperation brings significant benefits to each local government and stimulates them for further cooperation in pollution reduction. Finally, sensitivity analysis is performed using the year 2009 data to test the parameters’ effects on the pollution reduction cost savings.

Implications: China is increasingly facing unprecedented pressure for immediate air pollution control. The current air pollution reduction policy does not allow cooperation and is less efficient. In this paper we developed a cooperative air pollution reduction game model that consists of two parts: (1) an optimization model that calculates the optimal pollution reduction quantity for each participating province to meet the joint pollution reduction goal; and (2) a model that distributes the cooperation gains (i.e., cost reduction) among the provinces in the cooperation based on the Shapley value method. The empirical case shows that such a model can help improve efficiency in air pollution reduction. The result of the model can serve as a reference for Chinese government pollution reduction policy design.     

Fenton氧化法深度处理抗生素废水二级出水

采用Fenton氧化法对青霉素和土霉素混合废水二级处理出水进行深度处理,通过正交和单因素实验研究了废水初始反应pH值、H2O2投加量、Fe2+/H2O2摩尔比及反应时间等因素对废水处理效果的影响。实验结果表明,Fenton氧化法处理的最佳反应条件为:初始pH值4、H2O2(30%)投加量50 mL/L、Fe2+/H2O2摩尔比1/20和反应时间60 min,处理后出水COD小于120 mg/L,COD去除率在75%以上,急性毒性(HgCl2毒性当量)小于0.07 mg/L,满足《发酵类制药工业水污染物排放标准》(GB21903-2008)表2标准要求。     

湿法净化黑烟中添加剂对炭黑沉降性能的影响

湿法净化黑烟中炭黑颗粒物的关键在于降低吸收液的表面张力并以高性能絮凝剂使其从溶液中絮凝、沉降以利于分离。选用十六烷基三甲基溴化胺(CTAB)为主要表面活性剂,使之与十二烷基苯磺酸钠(SDBS)和月桂醇聚氧乙烯(9)醚(AEO-9)进行复配实验,研究了复配液的表面张力,再向最低表面张力的复配表面活性剂溶液中投加絮凝剂聚合氯化铝(PAC)和聚丙烯酰胺(PAM),探讨絮凝剂的添加对黑烟颗粒沉降和絮凝的影响.实验结果表明:同时添加表面活性剂CTAB,SDBS和PAC,并使之浓度分别为0.5 mmol/L,0.4 mmol/L和200 mg/L时,炭黑颗粒的沉降效果最好,沉降率高达94%,且絮凝体较大,沉降时间仅为2 min。     

灵芝漆酶对直接蓝86的催化脱色性能

利用灵芝菌Ganoderma lucidum U-281漆酶对直接蓝86进行酶促氧化脱色,并对其降解机理进行了探讨。结果表明,染料-漆酶共反应体系在20～50℃及pH小于5.0范围内,直接蓝86均可脱色50%以上;漆酶对直接蓝86具有宽泛的浓度适应性,对300 mg/L的该染料仍具有耐受性。最优脱色工艺参数为温度40℃、pH 5.0、染料初始浓度200 mg/L、漆酶用量1 U/mL。在优化条件下,直接蓝863 h的脱色率达到54.54%,48 h脱色率达到91.54%。紫外-可见吸收光谱分析表明,漆酶的酶促氧化导致染料的分子结构产生了变化,是造成直接蓝86脱色的主要发生机制。