Taihu Lake is the most important drinking water source of the major cities in the Yangtze River Delta. The pollution of endocrine disruptors (EDCs)in Taihu Lake has been increasing recently, the accurate determination is an important guide for predicting its health risks and developing appropriate controls. Monitoring organic pollutants in water using the diffusive gradient in thin film technique (DGT) has attracted much attention due to more accuracy and convenience than the grab sampling methods. In this study, a novel cyclodextrin polymer (CDP) synthesized by the simple and green method in water was taken as an adsorbent for the binding gel. Four endocrine-disrupting chemicals (EDCs), bisphenol A (BPA), 17α-ethinylestradiol (EE2), 17β-estradiol (E2), and estriol (E3), were taken as models to determine the diffusion coefficients (4.68×10 -6 , 3.38×10 -6 , 3.34×10 -6 and 4.31×10 -6 cm 2 /s) and to test the performance of DGT, such as adsorption capacity and deployment time (1-5 day). The assembled CDP-DGT was adopted to determine four EDCs in a simulated water environment (3-9 of pH, 0.001-0.5 M of ionic strength (IS), and dissolved organic matter (DOM) of 0-20 mg/L). The ability of CDP-DGT sampling was verified in the Jiuxiang River and was carried out for a large-scale field application of in situ sampling EDCs in Taihu Lake basin. The results show that the total EDCs concentration range and the estradiol equivalent concentrations (EEQ) in Taihu Lake and its main rivers are 2.78 ng/L to 11.08 ng/L and 2.62 ng/L to 10.91 ng/L, respectively. The risk quotients (RQs) of all sampling sites in the region were greater than 1, indicating that EDCs pose a serious threat to aquatic organisms in the area. Therefore, the monitoring of EDCs in the Taihu Lake basin should be further strengthened.
Simple synthesis of a swellable porous β-cyclodextrin-based polymer in the aqueous phase for the rapid removal of organic micro-pollutants from water.
Nitrochlorobenzene compounds (NCBs) are of key interest in environmental monitoring due to their high toxicity. To better understand the presence and fate of NCBs in aquatic environments, an in-situ sampling technique of diffusive gradients in thin films (DGT) based on hydrophilic-lipophilic-balanced (HLB) resin, combined with gas chromatography, was developed to measure four typical NCBs, e.g. meta-chloronitrobenzene (MNCB), para-chloronitrobenzene (PNCB), ortho-chloronitrobenzene (ONCB), and 2,4-dinitrochlorobenzene (CDNB). The diffusion coefficients of MNCB, PNCB, ONCB, and CDNB in agarose-based gel were firstly determined in diffusion cell experiments and ranged from 7.19 × 10-6 to 7.49 × 10-6 cm/s. The capacities of HLB-DGT for MNCB, PNCB, ONCB, and CDNB were higher than 114.65, 117.52, 117.72, and 37.58 μg/cm2, respectively. The HLB-DGT performance on NCBs determination was demonstrated to be independent of natural fluctuations in pH (3-9), ionic strength (0.001-0.5 M), and dissolved organic matter concentrations (0-20 mg/L) and of deployment time (0-120 h). In the field application, the DGT-based method to measure NCBs not only proved to be accurate and effective, but also performed better than the grab sampling method under the variable conditions. This study demonstrates that the newly developed in-situ method based on DGT can provide an attractive alternative for the routine monitoring of NCBs in aquatic environments.
This study investigated the simultaneous abatement of atmospheric volatile organic compounds (VOCs) and persistent organic pollutants (POPs), such as polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs), using an integrated technique with a bag filter (BF), photocatalysis (PC) and biotrickling filter (BTF) in an electronic waste (e-waste) dismantling workshop. Approximately 3.6×105, 1.1×103, and 2.5×103ngm−3 of VOCs, PAHs, and PBDEs, respectively, were emitted from domestic stoves during a television dismantling process. During 30-day continuous treatment period, the treatment techniques eliminated 83.7%, 87.2% and 94.1% of VOCs, PAHs and PBDEs, respectively. Among three technologies, PC was responsible for the removal of 78.0% of VOCs and 72.3% of PAHs, while the BF technology removed 85.5% of PBDEs. The success assembling of different technologies depended on different gas-particle distributions of PAHs and PBDEs. Meanwhile, the decreased risk indices of all pollutants were also observed. The PC and BF treatment technologies reduced the cancer risks associated with the most VOCs and PBDEs (57.6% and 80.5%, respectively). The BF technology reduced risks from PAHs the most (86.1%), because of much higher toxic equivalency factors associated with particle-related-PAHs. After BTF treatment, the residual organic pollutants were further biodegraded and completely detoxified. This study indicated that the integrated technique, involving both excellent de-dusting and decontamination capabilities, may provide an efficient alternative to current environment purification and human health protection practices.
Due to differences in stereostructure, enantiomeric compositions and enantiomeric ratios (ERs) of chiral compounds can be used to discriminate environmental processes such as abiotic and biotic degradation/transformation. In this study, the ERs of two chiral polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), were investigated in the sediments of Zhujiang River and Dongjiang River in the Pearl River Delta (PRD), as well as in those of Suzhou Creek in Shanghai City. The results indicated that ERcis of HHCB varied significantly, ranging from 1.09 to 1.53 and 1.40 to 1.48 in the PRD and Suzhou Creek samples, respectively, whereas ERtrans of HHCB exhibited limited variation, ranging from 0.98 to 1.10 and 0.98 to 1.05 for Pearl River and Suzhou Creek samples, respectively. In addition, ERs of AHTN varied substantially from 1.10 to 1.34 and 1.17 to 1.28 in the PRD and Suzhou Creek, respectively. These results suggest that HHCB in the sediment in the study area underwent biotic degradation and the preferential biotransformation isomer was (4R,7S)-HHCB, while AHTN simultaneously underwent a certain degree of biotic degradation/transformation.
Polycyclic aromatic hydrocarbons (PAHs) originating from vehicle exhaust have aroused much attention due to their potential healthy effect. In this study, air samples were collected from three representative parking lots in a metropolitan area, analyzed for PAHs and evaluated for inhalation risk. Atmospheric PAH levels of these parking areas ranged between 1178-4793 ng m(-3), one order of magnitude higher than general urban areas. Their benzo[a]pyrene equivalent (BaPeq) values varied in 11.0-98.0 ng m(-3), far exceeding the air quality standard of WHO (1.0 ng m(-3)). Monte Carlo simulation (100,000 trials) results suggest that the potential lifetime inhalation cancer risks of PAHs were 0.27 x 10(-5) to 7.11 x 10(-5) for park employees, which are in the acceptable range acknowledged by US EPA (1.0 x 10(-6) to 1.0 x 10(-4)). Several source diagnostic methods proved that vehicle exhaust was the dominant PAH contributor of these parks with the contribution percentages being >53%; oil combustion and/or coal combustion were other important sources. Logarithms of gas-particle distribution coefficients (K(p)s) of PAHs in all studied parks were linearly correlated with those of both their sub-cooled vapor pressures (P(L)s) and octanol-air partition coefficients (K(OA)s). The correlation coefficients indicated that both adsorption onto black carbon and absorption into organic matter were involved in the partition process, but the latter was dominant. (C) 2014 Elsevier B.V. All rights reserved.
An immunochromatographic strip method, developed with the excretory-secretory antigens from muscle larvae (ML) of Trichinella spiralis labeled with colloidal gold, was used for the detection of anti-Trichinella antibodies in serum of experimentally-infected swine. Sera from swine infected with 200, 2000 and 20,000 infective ML were collected at different days post infection (dpi) and used to evaluate the method. The strip method was shown able to detect anti-Trichinella antibodies by 35 dpi, 28 dpi and 21 dpi for the three different infection doses, respectively, and closely correlated with the results of an ELISA test. The strip method is rapid and easy to perform and is suggested as an acceptable alternative for clinical laboratories lacking specialized equipment, and for field diagnosis of trichinellosis.
Camel is important to the economy of many countries. We report Toxoplasma gondii infection in Bactrian camels (Camelus bactrianus), first for this host. Antibodies to T. gondii were found in sera of 7 of 234 C. bactrianus from Qinghai Province, northwestern China. Sera were tested by a commercial indirect hemagglutination test at a cut-off of 1:64. Age or the gender of the camel did not significantly affect the seroprevalence. Results are of public health and economic importance because camel milk and meat are used for human consumption in many countries, including China.
The levels and distribution of six polycyclic musks, three nitromusks and 15 polycyclic aromatic hydrocarbons (PAHs) were investigated in sludge collected from 19 municipal wastewater treatment plants (WWTPs) in six cities in Guangdong Province, China. PAHs were detected in all of the sludge samples, and the levels of the total 15 PAHs ranged from 177.2–4421.8 μg/kg dry weight (dw). Four polycyclic musks, 4-acetyl-1,1-dimethyl-6-tert-butylindan (ADBI), 6-acetyl-1,1,2,3,3,5-hexamethylindan (AHMI), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta (g) -2-benzopyran (HHCB) and 7-acetyl -1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydro naphthalene (AHTN), were found in these samples. The total concentrations of polycyclic musks varied from 794.4–12960.3 μg/kg dw, with HHCB and AHTN being the main components. Of the three nitromusks, 2,6-dinitro-3-methoxy-4-tert- butyl - toluene (MA) was only found in one sludge sample at the limit of detection (LOD) level, while 1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene (Musk xylene, MX) and 4-acetyl-1-tert-butyl-3,5-dimethyl-2,6-dinitrobenzene (Musk ketone, MK) were found at levels ranging from the LOD to 65.8 μg/kg dw and LOD to 172.7 μg/kg dw, respectively, in most of the sludge samples. The PAHs, polycyclic musks and nitro musks were also shown to have various distribution patterns, possibly due to their different wastewater sources and wastewater treatment technology.
A rapid and sensitive method was developed for the determination of eight nitrobenzenes and four nitrochlorobenzenes in water. The method is based on dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography-mass spectrometry (GC-MS). The key factors influencing the extraction efficiencies, including the nature and volume of the extraction and dispersion solvent and the ratios of the extraction solvent and dispersion solvent were examined and optimized. Under the optimized conditions, the method yields a linear correlation at a concentration range of 0.5 μg L−1–500.0 μg L−1 for all the target analytes with correlation coefficients (R2) of 0.9915 to 1.0000, and relative standard deviations (RSD, n = 6) of between 4.9% and 8.2%, depending on the compound analysed. In addition, good pre-concentration factors of 243 to 525 for each specific compound were achieved. These results suggest that the method presented herein is a rapid and powerful microextraction technique that is useful for the detection of these organic pollutants in water samples and is suitable for emergency monitoring.
In the present investigation, the seroprevalence of Toxoplasma gondii antibodies in 455 Tibetan sheep in Tibet, China, was examined using an indirect hemagglutination test. Of these, 26 (5.7%) Tibetan sheep were seropositive at the cut-off of 1:64 serum dilution. The seroprevalence ranged from 2.2% to 8.9% among Tibetan sheep of <1-yr-old, 1-3-yr-old, and >3-yr-old, but the differences among the age groups were not significant (P > 0.05). The prevalence in male Tibetan sheep (2.8%) was lower than that in female Tibetan sheep (6.6%), but the difference was not statistically significant (P > 0.05). The results of this survey indicated the presence of T. gondii infection in Tibetan sheep, which may cause economic losses to the local livestock industry and which poses a potential threat to human health in this area.
In this study the concentrations and distribution of sixteen polycyclic aromatic hydrocarbons (PAHs) were investigated in gas and total suspended particle (TSP) samples collected during daytime and night time. The sampling locations included an electronic waste dismantling workshop (EW), a plastic recycling workshop (PW) and a waste incineration field (WF) in Guiyu, China. A large residential area (RA) in this region was used as a control site. In the daytime, the highest concentration was found at WF (1041ngm−3); while in the night time the highest concentration was found outside of EW (744ngm−3). Comparison between work hours (daytime) and rest hours (night time) displayed that the total PAHs (gas+particulate phase) concentrations and the percentages of PAHs associated with TSP were higher at night than those in the daytime in all sampling workshops except WF. Source diagnostic-ratio analysis revealed that unwanted materials and smoldering honeycomb coals were the main sources of PAHs in EW, WF and PW. Benzo[a]pyrene equivalent [BaPeq] concentrations calculated by using the toxic equivalent factors [TEFs] suggested that the occupational exposure levels were not significantly high when compared with other occupational exposure. Additionally, our study suggested that the smoldering of unwanted materials could produce much more toxic PAHs compounds.
Gas samples and total suspended particle during work and off work time were investigated on-site and off-site electronic waste dismantling workshop (I- and O-EWDW), then compared with plastic recycling workshop (PRW) and waste incineration plant (WIP). TSP concern rations and total PBDE were 0.36-2.21 mg/m(3) and 27-2975 ng/m(3) at different workshops, respectively. BDE-47, -99, and -209 were major Sigma PBDE congeners at I-EWDW and MP, while BDE-209 was only dominant congener in PRW and control sites during work time and all sites during off work time. The gas-particle partitioning result was well correlated with the subcooled liquid vapor pressure for all samples, except for WIP and I-EDWD, at park during work time, and residential area during off work time. The predicted urban curve fitted well with measured phi values at O-DEWD during work time, whereas it was slightly overestimated or underestimated for others. Exposure assessment revealed the highest exposure site was I-EDWD. (C) 2011 Elsevier Ltd. All rights reserved.
The contamination of persistent organic pollutants (POPs) is a noticeable problem in the environment. Two types of POPs, including organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs), were investigated in this research. OCPs and PAHs were analyzed with GC-ECD and GC-MS, respectively, in three drinking water sources of Xijiang River in Guangdong province. The safety of drinking water sources based on the levels of OCPs and PAHs were also estimated. The concentrations of OCPs in dissolved phase ranged from 1.99 ng·L~(-1) to 4.76 ng·L~(-1), and in particulate phase from 0.36 ng·L~(-1) to 0.68 ng·L~(-1). And the levels of PAHs were between 73.40 ng·L~(-1) and 865.89 ng·L~(-1) in dissolved phase and between 16.76 ng·L~(-1) and 19.31 ng·L~(-1) in par-ticulate phase. The results showed that the concentrations of HCHs and DDTs were far below the Chinese Water Quality Standard for Drinking Water Sources (CJ 3020-93), and the concentrations of B[α]P were below the Drinking Water Standard, the guideline of World Health Organization. In conclusion, as for the levels of OCPs and PAHs, the source water for drinking in Xijiang River is rela-tively safe. However, the occurrence and risks of these two types of POPs should not be ignored due to their significant bioaccumula-tion.
The safety of source water is a noticeable problem in the Pearl River Delta, one of the densely populated areas in China. In this study, 20 individual organochlorine pesticides (OCPs) were investigated in 15 water sources within this area using gas chromatography-electron capture detector, and the hazard risks to human health were assessed in terms of individual OCPs based on daily water consumption according to the standard recommended by the United States Environmental Protection Agency. Results showed that the total OCP concentrations ranged from 2.42 ng l(-1) to 39.52 ng l(-1) during the years 2008 and 2009. The hazard ratios based on both non-cancer and cancer benchmarks were less than 1 for all the water samples, which indicated that individual OCPs posed no risk to human health. However, the risks caused by the combined toxicity of total OCPs in this area should not be ignored.
Combined technique of photocatalysis with biotechnology was used for the on-site control of organic waste gas emitted from paint production and processing factory.The results showed that the main components of the waste gas were toluene,ethyl-benzene,m/p-xylene and o-xylene.The concentration of the waste gas was in the range of 27~55 mg/m3.The removal efficiencies of these waste gases were relatively low and not satisfied if photocatalytical technology or biotechnology alone was applied to pilot-scale treatment of the emission gases.The average removal efficiencies of VOCs for photocatalysis and biotechnology were only 67.6% and 67.5% respectively at the steady stage,although the average removal efficiency of VOCs on photocatalysis was about 86.2% at the initial stage.However,the average removal efficiency was 99.2% when two single technologies of photocatalysis and biotechnology were combined together.
弓形虫是一种呈全球分布的专性细胞内寄生原虫,广泛寄生于人和动物的有核细胞内,能引起严重的人兽共患寄生虫病.因此,对弓形虫及弓形虫病的研究日趋得到学者们的重视.由于弓形虫生活史较复杂,抗原成分多,每种抗原在体内诱导的免疫效应不同,实验证明,单价亚单位疫苗免疫效果和单一抗原诊断试剂检测效果均不理想,研制多表位疫苗和诊断试剂必然是一个新的发展趋势.因此,正确而详细地了解蛋白质表位对疾病的诊断以及设计疫苗分子结构具有重要理论和现实意义.本文就弓形虫表位研究进展加以综述.
To eliminate volatile organic compounds (VOCs) from contaminated air, a novel medium-scale baffled photocatalytic reactor was designed and fabricated, using immobilized ZnO/SnO2 coupled oxide photocatalysts. Toluene was chosen as a representative pollutant of VOCs to investigate the degradation mechanism and the parameters affecting photocatalytic degradation efficiency. The preliminary experimental results indicate that the degradation efficiency of toluene increased with the increase of the light irradiation dosage, while it decreased with the increase of concentrations of toluene. The degradation efficiency increased rapidly with the increase of the relative humidity in a low humidity range from 0 to 35%, but decreased gradually in a high relative humidity (i.e., >35%). The optimum experimental conditions for toluene degradation is a toluene concentration of 106 mg m−3, a relative humidity of 35%, and an illumination intensity of ca. 6 mW cm−2 at the surface of ZnO/SnO2 photocatalysts. The intermediates produced during the gaseous photocatalytic degradation process were identified using the GC–MS technique. Based on these identified intermediates, the photocatalytic mechanism of toluene into ZnO/SnO2 coupled oxide catalyst was also deduced.
Two species of Trichinella were identified from China by means of PCR amplification of the mitochondrial small subunit ribosomal DNA and the expansion segment V region of the ribosomal DNA. Seven isolates originating from domestic pig and one isolate originating from dog showed identical DNA banding pattern to Trichinella spiralis, and two isolates from dog showed DNA banding pattern identical to Trichinella nativa. Sequence analysis of the 5S rDNA inter-gene spacer region from the ten Trichinella isolates confirmed the existence of only two Trichinella species and revealed the inner species genetic variation within T. spiralis and T. nativa.