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Dissolved organic carbon from sewage sludge and manure can affect estrogen sorption and mineralization in soils Полный текст
2010
Stumpe, Britta | Marschner, Bernd
In this study, effects of sewage sludge and manure borne dissolved organic carbon (DOC) on 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) sorption and mineralization processes were investigated in three agricultural soils. Batch equilibrium techniques and equilibrium dialysis methods were used to determine sorption mechanisms between DOC, estrogens and the soil solid phase. It was found that that the presence of organic waste borne DOC decreased estrogen sorption in soils which seems to be controlled by DOC/estrogen complexes in solution and by exchange processes between organic waste derived and soil borne DOC. Incubation studies performed with 14C-estrogens showed that DOC addition decreased estrogen mineralization, probably due to reduced bioavailability of estrogens associated with DOC. This increased persistence combined with higher mobility could increase the risk of estrogen transport to ground and surface waters. The effect of DOC on estrogen sorption and mineralization is influenced by exchange processes between organic waste borne and soil derived DOC.
Показать больше [+] Меньше [-]Mobility of arsenic, cadmium and zinc in a multi-element contaminated soil profile assessed by in-situ soil pore water sampling, column leaching and sequential extraction Полный текст
2010
Beesley, Luke | Moreno-Jiménez, Eduardo | Clemente, Rafael | Lepp, Nicholas | Dickinson, Nicholas
Three methods for predicting element mobility in soils have been applied to an iron-rich soil, contaminated with arsenic, cadmium and zinc. Soils were collected from 0 to 30 cm, 30 to 70 cm and 70 to 100 cm depths in the field and soil pore water was collected at different depths from an adjacent 100 cm deep trench. Sequential extraction and a column leaching test in the laboratory were compared to element concentrations in pore water sampled directly from the field. Arsenic showed low extractability, low leachability and occurred at low concentrations in pore water samples. Cadmium and zinc were more labile and present in higher concentrations in pore water, increasing with soil depth. Pore water sampling gave the best indication of short term element mobility when field conditions were taken into account, but further extraction and leaching procedures produced a fuller picture of element dynamics, revealing highly labile Cd deep in the soil profile. Mobility of arsenic, cadmium and zinc in a polluted soil can be realistically interpreted by in-situ soil pore water sampling.
Показать больше [+] Меньше [-]Pd-nanoparticles cause increased toxicity to kiwifruit pollen compared to soluble Pd(II) Полный текст
2010
Speranza, Anna | Leopold, Kerstin | Maier, Marina | Taddei, Anna Rita | Scoccianti, Valeria
In the present study, endpoints including in vitro pollen performance (i.e., germination and tube growth) and lethality were used as assessments of nanotoxicity. Pollen was treated with 5–10 nm-sized Pd particles, similar to those released into the environment by catalytic car exhaust converters. Results showed Pd-nanoparticles altered kiwifruit pollen morphology and entered the grains more rapidly and to a greater extent than soluble Pd(II). At particulate Pd concentrations well below those of soluble Pd(II), pollen grains experienced rapid losses in endogenous calcium and pollen plasma membrane damage was induced. This resulted in severe inhibition and subsequent cessation of pollen tube emergence and elongation at particulate Pd concentrations as low as 0.4 mg L−1. Particulate Pd emissions related to automobile traffic have been increasing and are accumulating in the environment. This could seriously jeopardize in vivo pollen function, with impacts at an ecosystem level. Nanoparticulate Pd – which resembles emissions from automobile catalysts – affects pollen to a higher extent than soluble Pd.
Показать больше [+] Меньше [-]Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China Полный текст
2010
Tao, Ran | Ying, Guang-Guo | Su, Hao-Chang | Zhou, Hong-Wei | Sidhu, Jatinder P.S.
This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta.
Показать больше [+] Меньше [-]Historical mercury contamination in sediments and catchment soils of Diss Mere, UK Полный текст
2010
Yang, Handong
A 5.3 m sediment core and soil samples were taken from Diss Mere and its catchment. The sediment core was dated and Hg analysed on the sediment and soil samples. The Hg record of the sediment core shows that Diss Mere has been contaminated for the past thousand years and the historical trends in sediment contamination are in good agreement with the development of the weaving industry in Diss and hemp cultivation in the region. Mercury contamination in Diss Mere has been significant and reached a peak in the mid-19th century with sediment Hg concentrations over 50 μg g-1. Elevated Hg concentrations were also found in contemporary soils in residential areas with former industrial land use. Although local hemp cultivation and the traditional weaving industry were abandoned a hundred years ago, Hg contamination caused by these activities still exists in the catchment, and affects the lake.
Показать больше [+] Меньше [-]Synthesis of core-shell magnetic molecular imprinted polymer by the surface RAFT polymerization for the fast and selective removal of endocrine disrupting chemicals from aqueous solutions Полный текст
2010
Li, Ying | Li, Xin | Chu, Jia | Dong, Cunku | Qi, Jingyao | Yuan, Yixing
In this study, we present a general protocol for the making of surface-imprinted core-shell magnetic beads via reversible addition-fragmentation chain transfer (RAFT) polymerization using RAFT agent functionalized iron oxide nanoparticles as the chain transfer agent. The resulting composites were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analysis, thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface-imprinted magnetic beads were demonstrated with a homogeneous polymer films (thickness of about 22 nm), spherical shape, and exhibited magnetic property (Ms = 0.41 mA m2 g−1) and thermal stability. Rebinding experiments were carried out to determine the specific binding capacity and selective recognition. The as-synthesized surface-imprinted core-shell magnetic beads showed outstanding affinity and selectivity towards bisphenol A over structurally related compounds, and easily reach the magnetic separation under an external magnetic field. In addition, the resulting composites reusability without obviously deterioration in performance was demonstrated at least five repeated cycles.
Показать больше [+] Меньше [-]The profile of antibiotics resistance and integrons of extended-spectrum beta-lactamase producing thermotolerant coliforms isolated from the Yangtze River basin in Chongqing Полный текст
2010
Chen, Hao | Shu, Weiqun | Chang, Xiaosong | Chen, Ji-an | Guo, Yebin | Tan, Yao
The spreading of extended-spectrum β-lactamases (ESBL)-producing thermotolerant coliforms (TC) in the water environment is a threat to human health but little is known about ESBL-producing TCs in the Yangtze River. We received 319 ESBL-producing stains obtained from the Chongqing basin and we investigated antibiotic susceptibility, bla gene types and the presence of integrons and gene cassettes. 16.8% of TC isolates were ESBL-producing bacteria and blaTEM+CTx-M was the predominant ESBL type. 65.2% of isolates contained class 1 integrons, but only 3 carried intI 2. Gene cassettes were amplified and sequenced. aadA, drfA, cmlA, sat1, aar3 and two ORF cassettes were found. In conclusion, Yangtze River is heavily polluted by ESBL-producing TC bacteria and the combined bla gene type could enhance antibiotic resistance. Class 1 integrons were widespread in ESBL-producing isolates and play an important role in multi-drug resistance. Characterization of gene cassettes could reveal the dissemination of antibiotic resistance genes.
Показать больше [+] Меньше [-]Assessment of the emission of PCDD/Fs and dioxin-like PCBs from an industrial area over a nearby town using a selective wind direction sampling device Полный текст
2010
Martínez, Karell | Austrui, Joan Rivera | Jover, Eric | Ábalos, Manuela | Rivera, Josep | Abad, Esteban
Assessment of the emission of PCDD/Fs and dioxin-like PCBs from an industrial area over a nearby town using a selective wind direction sampling device Полный текст
2010
Martínez, Karell | Austrui, Joan Rivera | Jover, Eric | Ábalos, Manuela | Rivera, Josep | Abad, Esteban
The development of new sampling devices or strategies to assess the concentration of persistent organic pollutants (POPs) in the environment has increased in the last two decades. In this study, a selective sampling device was used to evaluate the impact of potential local sources of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) and dioxin-like polychlorinated biphenyl (dl-PCBs) emissions on the ambient air levels of such compounds in a town near an important industrial estate. Average concentrations of target compounds of up to 2.5 times for PCDD/Fs and 2 times for dl-PCBs were found to come from the industrial state confirming this area as the main responsible for the majority of such compounds reaching the town. This finding was supported by a PCDD/F and dl-PCB sample profile analysis and a principal component analysis (PCA), which established a direct link between the dioxin-like compounds found in the samples collected in the town and their source. Selective ambient air samplers provide a valuable information on POP emission sources.
Показать больше [+] Меньше [-]Assessment of the emission of PCDD/Fs and dioxin-like PCBs from an industrial area over a nearby town using a selective wind direction sampling device Полный текст
2010
Martínez, Karell | Rivera Austrui, Joan | Jover, Eric | Ábalos, Manuela | Rivera, Josep | Abad Holgado, Esteban
The development of new sampling devices or strategies to assess the concentration of persistent organic pollutants (POPs) in the environment has increased in the last two decades. In this study, a selective sampling device was used to evaluate the impact of potential local sources of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) and dioxin-like polychlorinated biphenyl (dl-PCBs) emissions on the ambient air levels of such compounds in a town near an important industrial estate. Average concentrations of target compounds of up to 2.5 times for PCDD/Fs and 2 times for dl-PCBs were found to come from the industrial state confirming this area as the main responsible for the majority of such compounds reaching the town. This finding was supported by a PCDD/F and dl-PCB sample profile analysis and a principal component analysis (PCA), which established a direct link between the dioxin-like compounds found in the samples collected in the town and their source. | Peer reviewed
Показать больше [+] Меньше [-]Prediction of the PCDD/F and dl-PCB 2005-WHO-TEQ content based on the contribution of six congeners: Toward a new screening approach for fish samples Полный текст
2010
Cariou, Ronan | Marchang, Philippe | Vénisseau, Anaïs | Brosseaud, Aline | Bertrand, Dominique | Qannari, El Mostafa | Antignac, Jean-Philippe | Le Bizec, Bruno
Current European Union regulation regarding polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in food and feed is based on Toxic Equivalent Quotient (TEQ) concept. For confirmatory purpose, the isotope-dilution method associated to a measurement by gas chromatography coupled with high resolution mass spectrometry is usually the method of choice for precisely measuring the 29 target congeners in three separated fractions. Time and cost related to these analyses are very significant. Various kinds of screening concepts can be considered. In the present study, we elaborated and validated a prediction model for the 2005 World Health Organization TEQ in fish, based on the measurement of 4 PCDD/F and 2 non-ortho dl-PCB congeners, potentially analyzable in a single extracted fraction by gas chromatography coupled with mass spectrometry. Large independent datasets have been used for model elaboration (n = 108) and validation (n = 363, n = 357 and n = 6). This study describes a statistical regression model approach for screening PCDD/Fs and dl-PCBs in fish.
Показать больше [+] Меньше [-]Exposure to perfluorooctane sulfonic acid (PFOS) adversely affects the life-cycle of the damselfly Enallagma cyathigerum Полный текст
2010
Bots, Jessica | Bruyn, Luc de | Snijkers, Tom | Branden, Bert van den | Gossum, Hans van
We evaluated whether life-time exposure to PFOS affects egg development, hatching, larval development, survival, metamorphosis and body mass of Enallagma cyathigerum (Insecta: Odonata). Eggs and larvae were exposed to five concentrations ranging from 0 to 10 000 μg/L. Our results show reduced egg hatching success, slower larval development, greater larval mortality, and decreased metamorphosis success with increasing PFOS concentration. PFOS had no effect on egg developmental time and hatching or on mass of adults. Eggs were the least sensitive stage (NOEC = 10 000 μg/L). Larval NOEC values were 1000 times smaller (10 μg/L). Successful metamorphosis was the most sensitive response trait studied (NOEC < 10 μg/L). The NOEC value suggests that E. cyathigerum is amongst the most sensitive freshwater organisms tested. NOEC for metamorphosis is less than 10-times greater than the ordinary reported environmental concentrations in freshwater, but is more than 200-times smaller than the greatest concentrations measured after accidental releases. Long-term laboratory exposure to perfluorooctane sulfonic acid reduces survival and interferes with metamorphosis of Enallagma cyathigerum (Insecta: Odonata).
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