Fangxing Yang

Seasonal variations of estrogenic compounds and their estrogenicities in influent and effluent from a municipal sewage treatment plant in China

The seasonal variations of estrogenic compounds and the estrogenicities of influent and effluent were investigated by chemical analysis and in vitro assay in a municipal sewage treatment plant in Wuhan (China). The levels of eight estrogenic compounds, including 17beta-estradiol (E(2)), estrone (E(1)), estriol (E(3)), diethylstilbestrol (DES), 17alpha-ethinylestradiol, nonylphenol (NP), 4-tert-octylphenol (OP), and bisphenol A (BPA), were measured by gas chromatography-mass spectrometry. Total estrogenic activity of sewage was quantitatively assessed using primary cultured hepatocytes of male Megalobrama amblycephala Yih using vitellogenin as a biomarker. The E(2) equivalents (EEQs) obtained from the chemical analysis were consistent with those measured by bioassay. The natural (E(1), E(2), and E(3)) and synthetic (DES) estrogens, as well as NP, were the main contributors of the total EEQs of influent and effluent in the present study. The levels of natural estrogens E(1) and E(3) in the influent and effluent were higher in winter than in summer, whereas the situation for NP and OP was the reverse. The levels of E(2), DES, and BPA varied little among different seasons. 17alpha-Ethinylestradiol was not detected in the influent and effluent. The estrogenicities of the influent and of the primary and secondary effluents were all higher in summer than in winter. Estrogenic activities in winter mainly originated from natural (E(1), E(2), and E(3)) and synthetic (DES) estrogens, whereas the increase of EEQs in summer was contributed by NP. The results from chemical analysis and bioassay demonstrate that estrogenic compounds cannot be entirely removed by the existing sewage treatment process, which should be further improved to protect aquatic ecosystems and human health.

Bioaccumulative characteristics of hexabromocyclododecanes in freshwater species from an electronic waste recycling area in China

Hexabromocyclododecanes (HBCDs) are now emerging ubiquitous contaminants due to their wide usage, persistence and toxicities. To investigate the bioaccumulative characteristics of HBCDs, sediments, Winkle (Littorina littorea), crucian carp (Carassius carassius) and loach (Misgurnus anguillicaudatus) were collected from two streams near an E-waste dismantling site in China, and HBCD exposure test was then conducted on Chinese rare minnow. The concentration of HBCDs was 14 ng g(-1) dry weight in sediments, 186, 377 and 1791 ng g(-1) lipid weight in winkle, crucian carp and loach, respectively. gamma-HBCD was found to be the dominant diastereoisomer in the sediments (63% of total HBCDs). However, alpha-HBCD was selectively accumulated in the biotic samples and contributed to 77%, 63% and 63% of total HBCDs in winkle, crucian carp and loach, respectively. Moreover, an enrichment of (-)-enantiomers of alpha- and gamma-HBCD were found in the winkle. The reverse results were observed in the crucian carp and loach. Similar observations of diastereoisomeric and enantiomeric composition were obtained in Chinese rare minnow with those found in the crucian carp and loach. These results indicate that the freshwater species from the streams are contaminated by HBCDs. alpha-HBCD can be selectively accumulated in organisms and the accumulative characteristics are enantioselective among species.

Preliminary hazard assessment of polychlorinated biphenyls, polybrominated diphenyl ethers, and polychlorinated dibenzo‐p‐dioxins and dibenzofurans to yangtze finless porpoise in dongting lake, china

Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis), a protected endangered species, is the sole freshwater subspecies of finless porpoise, living only in the middle and lower reaches of the Yangtze River, China, and its appended lakes. Its population has decreased sharply to 1,400 because of human activities, including environmental contamination. In the present study, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined in the blubber, liver, kidney, stomach, small intestine, and brains of five individual Yangtze finless porpoises collected from 1998 to 2004. The results showed PCB concentrations ranged from 0.06 to 1.89 microg/g lipid weight in the organs and consisted mainly of penta-, hexa-, and decachlorinated biphenyls. The PBDE concentrations were between 5.32 and 72.76 ng/g lipid weight. Tetra-, penta-, and hexabrominated diphenyl ethers were the major homologues. The PCDD/F concentrations ranged from 65 to 1,563 pg/g lipid weight, and their predominant homologues were penta- and hexachlorinated dibenzofurans and hepta- and octachlorinated dibenzo-p-dioxins. The hazard quotients (HQs) based on toxic equivalency were determined to be greater than one in all individuals for PCBs, for PCDD/Fs, and for PCBs and PCDD/Fs In addition, HQs would be higher if PBDEs were included. The results suggest that reduction of environmental contamination may contribute greatly to protecting this highly endangered species.

Oxidative damage in unfertilized eggs of Chinese rare minnow (Gobiocypris rarus) exposed to nonylphenol

In the present study, female Chinese rare minnows (Gobiocypris rarus) were used as in vivo models and exposed to nonylphenol (NP) at concentrations of 1 to 200 microg/L for 21 d under semistatic conditions. Molecular biomarkers of oxidative stress were measured in unfertilized eggs and included reactive oxygen species (ROS), lipid peroxidation products (thiobarbituric acid- reactive substances [TBARS] and protein carbonyl), superoxide dismutase activity, and glutathione. Cathepsin D activity as an indicator of egg viability also was assayed. Nonylphenol induced ROS formation in unfertilized eggs in all exposed groups compared to the controls. The levels of protein carbonyl and TBARS in unfertilized eggs were significantly increased (p < 0.05) at 10 to 200 and 100 to 200 microg/L, respectively. Good positive correlations were shown between ROS induction and levels of TBARS and protein carbonyl in eggs (R = 0.918, p < 0.05 and R = 0.784, p < 0.05, respectively). Superoxide dismutase activity in eggs was significantly inhibited (p < 0.05) in the 50 to 200 microg/L exposure groups. Glutathione levels in eggs were significantly depleted (p < 0.05) at 100 to 200 microg/L concentrations. In addition, ROS induction resulted in oxidative damage to lipid and protein in chorions. Significant reductions (p < 0.05) of the protein and lipid contents in chorions were both found in the 50 to 200 microg/L exposure groups. A previous study found that NP exposure could lead to chorion thinning in zebra fish. Thus, the reductions in protein and lipid contents in chorion could be the reason for chorion thinning by NP exposure. Meanwhile, cathepsin D activity was significantly inhibited (p < 0.05) in all exposure groups. The results demonstrated that NP-induced oxidative stress could damage the chorion of unfertilized eggs and lead to a decline in gamete quality in female Chinese rare minnow.

Comparisons of IL-8, ROS and p53 responses in human lung epithelial cells exposed to two extracts of PM2.5 collected from an e-waste recycling area, China

To identify the different effects of organic-soluble and water-soluble pollutants adsorbed on PM2.5 (PM: particulate matter) released from e-waste (electrical/electronic waste) on inflammatory response, oxidative stress and DNA damage, interleukin-8 (IL-8), reactive oxygen species (ROS) and p53 protein levels were determined and compared in human lung epithelial A549 cells exposed to extracts of PM2.5 collected from two sampling sites in an e-waste recycling area in China. It is found that both extracts induced increases of IL-8 release, ROS production and p53 protein expression. The differences between the organic-soluble and water-soluble extracts were determined as of significance for ROS production (p < 0.05) and p53 protein expression (p < 0.01). The ROS production and p53 protein expression induced by the organic-soluble extracts were found to be greater than those induced by the water-soluble extracts, for both sampling sites. The results indicated that PM2.5 collected from the e-waste recycling areas could lead to inflammatory response, oxidative stress and DNA damage, and the organic-soluble extracts had higher potential to induce such adverse effects on human health.

Solid phase extraction with pyrenebutyric acid-bonded silica for analysis of polychlorinated biphenyls in sewage water by gas chromatography-mass spectrometry

A solid phase extraction (SPE) method using pyrenebutyric acid-bonded silica (PYB) as sorbent was developed to determine 23 polychlorinated biphenyls (PCBs) in sewage water by gas chromatography-mass spectrometry (GC-MS). Factors were optimized in SPE procedures including elution solvent, pH, and cartridge burden. The recoveries of 23 PCB congeners were 69.44-111.91% under optimized conditions. Comparisons were also conducted among PYB-SPE, C(18)-SPE and United States Environmental Protection Agency 608 (USEPA608) methods in the analysis of PCBs in sewage water samples. The results showed that the performance of PYB-SPE method was similar with USEPA608 method and better than C(18)-SPE method. Both PYB-SPE and USEPA608 methods were then employed to analyze PCBs in real spiked sewage water samples. The recoveries of PCB congeners determined by PYB-SPE method ranged from 70.6% to 92.4% in real spiked sewage water samples which were identified to be in accordance with USEPA608 method. Limits of detection (LOD) were in the range of 0.06-0.22ngL(-1) for PCB congeners. The optimized PYB-SPE method was successfully applied to the determination of PCBs in sewage water samples.

Multi-endpoint toxicities on Chinese rare minnow (Gobiocypris rarus) fed with different diets.

To compare the effects of three diets, rare minnow was fed with three diets from 30 dph to mature period. The activities of EROD, PROD, SOD and GST were measured in the WBHs as well as Vtg and TBARS concentrations at 60 dph. The rest fish were fed until adulthood for breeding studies. The group A served as the control group. It was found that Vtg, GST and EROD were significantly increased in the groups B and C, but SOD, TBARS and PROD levels were significantly increased only in the group C. In the adulthood, Vtg was significantly induced in the males in the group C. In generation F1, inhibition of CAT D activities and decrease of reproductive success were only found in pellet A group, but not in pellet B group. These findings indicate that the selection of diet is extremely important to assure veracity of the experiment results.