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Результаты 2081-2090 из 2,512
Impact assessment of human diet changes with rapid urbanization on regional nitrogen and phosphorus flows—a case study of the megacity Shanghai Полный текст
2014
Liu, Chen | Zou, Chunjing | Wang, Qinxue | Hayashi, Yoshitsugu | Yasunari, Tetsuzo
Regional material flows are strongly influenced by human diets. To diagnose and prevent environmental problems that threaten urban sustainability, the impact of human diet changes with rapid urbanization on the regional nitrogen (N) and phosphorus (P) flows were quantitatively evaluated. A survey of day-to-day activities was conducted of 450 individuals surveyed (adults over 18 years old) in three representative areas (the central district, the new district, and the suburban/rural areas) of Shanghai, a megacity which has attracted worldwide attention. The lifestyle (eating habits, domestic sanitation, drainage facilities, etc.) pattern was determined and the potential N and P loads from human diets on the environment were calculated. The daily potential nitrogen and phosphorus loads from human diets was 19.36 g-N, 1.80 g-P in the central district, 16.48 g-N, 1.52 g-P in the new district, and 13.04 g-N, 1.20 g-P in the suburban/rural areas of Shanghai. Respondents in all three areas, especially those in the suburban/rural areas reported a preference for increasing the intake of animal-derived as well as processed foods, which means that the potential N and P load from human diets to the environment will increase further. In addition, most respondents consider industrial wastewater discharge as the main cause of eutrophication of waterbodies, though in recent years water pollution caused by domestic wastewater has increased rapidly, but this has received much less attention. Environment-friendly eating habits and improvements in the environmental awareness will be required.
Показать больше [+] Меньше [-]Rapid determination of trace dicyandiamide in mussels from Zhejiang coast by ultra-fast liquid chromatography–tandem mass spectrometry with isotope internal standard dilution technique Полный текст
2014
Zhang, Yun | Gong, Wen-Jie | Zhao, Yong-Gang | Zhou, Hua
In this study, a rapid and accurate ultra-fast liquid chromatography–tandem quadrupole mass spectrometry (UFLC–MS/MS) method coupled with the isotope internal standard dilution technique was established and validated to determine trace dicyandiamide (DCD) in mussels. The sample was extracted by acetonitrile, and chromatographic separations were performed on an Acquity UPLC BEH Amide column by using water–acetonitrile (9:91, v/v) as the mobile phase within 3 min. DCD was determined by using DCD-¹⁵N₄as an internal standard. The results showed that the recoveries were between 96.2 and 103 % with relative standard deviations (RSDs) in the range of 0.6–6.0 %. The limit of quantification (LOQ) was 0.05 μg/kg. This method can be applied to the routine analysis for the rapid and sensitive determination of trace DCD in mussels. Overall, the data reiterate the importance of investigating the presence of DCD in marine biological samples, which can act as food quality controls for human health.
Показать больше [+] Меньше [-]Tire tread wear particles in ambient air—a previously unknown source of human exposure to the biocide 2-mercaptobenzothiazole Полный текст
2014
Avagyan, Rozanna | Sadiktsis, Ioannis | Bergvall, Christoffer | Westerholm, Roger
Urban particulate matter (PM), asphalt, and tire samples were investigated for their content of benzothiazole and benzothiazole derivates. The purpose of this study was to examine whether wear particles, i.e., tire tread wear or road surface wear, could contribute to atmospheric concentrations of benzothiazole derivatives. Airborne particulate matter (PM₁₀) sampled at a busy street in Stockholm, Sweden, contained on average 17 pg/m³ benzothiazole and 64 pg/m³ 2-mercaptobenzothiazole, and the total suspended particulate-associated benzothiazole and 2-mercaptobenzothiazole concentrations were 199 and 591 pg/m³, respectively. This indicates that tire tread wear may be a major source of these benzothiazoles to urban air PM in Stockholm. Furthermore, 2-mercaptobenzothiazole was determined in urban air particulates for the first time in this study, and its presence in inhalable PM₁₀ implies that the human exposure to this biocide is underestimated. This calls for a revision of the risk assessments of 2-mercaptobenzothiazole exposure to humans which currently is limited to occupational exposure.
Показать больше [+] Меньше [-]Pollution due to hazardous glass waste Полный текст
2014
Pant, Deepak | Singh, Pooja
Pollution resulting from hazardous glass (HG) is widespread across the globe, both in terms of quantity and associated health risks. In waste cathode ray tube (CRT) and fluorescent lamp glass, mercury and lead are present as the major pollutants. The current review discusses the issues related to quantity and associated risk from the pollutant present in HG and proposes the chemical, biological, thermal, hybrid, and nanotechniques for its management. The hybrid is one of the upcoming research models involving the compatible combination of two or more techniques for better and efficient remediation. Thermal mercury desorption starts at 100 °C but for efficient removal, the temperature should be >460 °C. Involvement of solar energy for this purpose makes the research more viable and ecofriendly. Nanoparticles such as Fe, Se, Cu, Ni, Zn, Ag, and WS₂alone or with its formulation can immobilize heavy metals present in HG by involving a redox mechanism. Straight-line equation from year-wise sale can provide future sale data in comparison with lifespan which gives future pollutant approximation. Waste compact fluorescent lamps units projected for the year 2015 is 9,300,000,000 units and can emit nearly 9,300 kg of mercury. On the other hand, CRT monitors have been continuously replaced by more improved versions like liquid crystal display and plasma display panel resulting in the production of more waste. Worldwide CRT production was 83,300,000 units in 2002 and can approximately release 83,000 metric tons of lead.
Показать больше [+] Меньше [-]A review of strategies to monitor water and sediment quality for a sustainability assessment of marine environment Полный текст
2014
Tavakoly Sany, Seyedeh Belin | Hashim, Rosli | Rezayi, Majid | Salleh, Aishah | Safari, Omid
The basic aim of this work is (1) to review and present practically operational requirements for a sustainability assessment of marine environment, such as describing the monitoring process, research approaches, objectives, guidelines, and indicators and (2) to illustrate how physico-chemical and biological indicators can be practically applied, to assess water and sediment quality in marine and coastal environment. These indicators should meet defined criteria for practical usefulness, e.g. they should be simple to understand and apply to managers and scientists with different educational backgrounds. This review aimed to encapsulate that variability, recognizing that meaningful guidance should be flexible enough to accommodate the widely differing characteristics of marine ecosystems.
Показать больше [+] Меньше [-]Organochlorine pesticides and polychlorinated biphenyls in Tibetan forest soil: profile distribution and processes Полный текст
2014
Wang, Xiaoping | Xue, Yonggang | Gong, Ping | Yao, Tandong
Tibetan forests are located in the southeastern Tibetan Plateau, where the climate is dominated by the Indian monsoon. Due to the affinity to pollution sources and high organic carbon stocks, the fate of persistent organic pollutants in the Tibetan forests should be given more attention. In this study, seven soil profiles were investigated to obtain the vertical distribution of the organochlorine pesticides and polychlorinated biphenyls (PCBs) in the Tibetan forest soil. The results indicate that the DDTs are highly stable in the soil, with limited volatilization and leaching, while the more volatile PCBs were found in the deeper mineral layer, which means that they can translocate through the organic layer and move farther downward into the deep soil. The air-to-ground fluxes (estimated by the age of the organic layer) of the DDTs are one magnitude higher than those reported in a study on the Alps, suggesting the higher accumulation of DDTs by the Tibetan forest.
Показать больше [+] Меньше [-]Synergic degradation of diesel by Scirpus triqueter and its endophytic bacteria Полный текст
2014
Zhang, Xinying | Chen, Lisha | Liu, Xiaoyan | Wang, Chuanhua | Chen, Xueping | Xu, Gang | Deng, Kaifang
The endophytic bacterium isolated from Scirpus triqueter was proved to be an oil-degraded bacterium. A pot experiment was conducted to investigate the removal ratio of diesel under the combined effect of oil-degraded microorganism (Pseudomonas sp. J4AJ) and S. triqueter. The effect of diesel on plant growth parameters, soil enzymes and microbial community was assessed after 60 days. The results showed that the soils which were planted with S. triqueter and inoculated with J4AJ displayed the highest removal ratio (54.51 ± 0.15 %) after 60-day experiment. However, the removal ratio of J4AJ-treated soils was 38.97 ± 0.55 %. Diesel was toxic to S. triqueter, as evidenced by growth inhibition during the experimental period. However, the plant height and stem biomass in the soils inoculated with J4AJ significantly increased. The combined effect of S. triqueter and J4AJ improved the enzyme activities of the catalase and dehydrogenase in the contaminated soil. The diversity index in soils under the effect of S. triqueter combined with J4AJ was lower than that of the other soil samples. The principal analysis of phospholipid fatty acid signatures revealed that the combined effect of S. triqueter and J4AJ increased the differences of soil microbial community structure with the other treatments.
Показать больше [+] Меньше [-]Urinary concentrations of trichlorophenols in the Korean adult population: results of the National Human Biomonitoring Survey 2009 Полный текст
2014
Kim, Kisok | Park, Hyejin | Lee, Jin Heon
Trichlorophenols such as 2,4,5-trichlorophenol (2,4,5-TCP) and 2,4,6-trichlorophenol (2,4,6-TCP) are organochlorine compounds to which the general public can be exposed via contaminated food, water, and air. This study assessed exposure to 2,4,5-TCP and 2,4,6-TCP in Koreans age 18–69 years based on the Korean National Human Biomonitoring Survey conducted in 2009. Using data from 1,865 representative Koreans, we found that the geometric mean urinary concentrations of 2,4,5-TCP and 2,4,6-TCP were 83.4 pg/mL [95 % confidence interval (CI) = 78.6–88.6] and 0.39 ng/mL (95 % CI = 0.35–0.42), respectively. The creatinine-adjusted geometric mean 2,4,5-TCP and 2,4,6-TCP levels were 78.8 ng/g creatinine (95 % CI = 73.8–84.1) and 0.36 μg/g creatinine (95 % CI = 0.33–0.40), respectively. Of the Korean adult population, about 67.5 and 87.5 % had respective urine 2,4,5-TCP and 2,4,6-TCP concentrations >0.05 ng/mL (the limit of detection, LOD). Urine 2,4,5-TCP concentrations were significantly associated with age and place of residence, whereas urine 2,4,6-TCP concentrations were higher in rural residents. These findings suggest that most Koreans had detectable levels of 2,4,5-TCP and 2,4,6-TCP in their urine and that the body burden of 2,4,5-TCP and 2,4,6-TCP varied according to demographic and geographic factors.
Показать больше [+] Меньше [-]Determination of phthalates and their by-products in tissues of roach (Rutilus rutilus) from the Orge river (France) Полный текст
2014
Valton, A. S. | Serre-Dargnat, C. | Blanchard, M. | Alliot, F. | Chevreuil, M. | Teil, Marie Jeanne
Seven phthalate by-products were investigated for the first time, in target tissues of roach from a contaminated river of the Ile-de-France district. All parent phthalates were bioaccumulated in liver and muscle and liver contents were correlated with river concentrations (p < 0.01). All metabolites were found in liver, plasma and bile. The mono-iso-butyl phthalate (MiBP; 1.6 μg g⁻¹dw of liver), followed by mono-n-butyl phthalate (MnBP; 1.5 μg g⁻¹dw of liver) were the most abundant ones. Among the three metabolites of di-ethylhexyl phthalate (DEHP), mono (2-ethylhexyl) phthalate (MEHP) predominated in bile (15.5 ng ml⁻¹) and liver (0.237 μg g⁻¹dw), whereas in plasma, it was mono (2-ethyl-5-hydroxyhexyl) phthalate – MEHHP (214 ng ml⁻¹). In liver, MEHP/DEHP ratios ranged from 0.04 to 0.2. Among the oxidized metabolites, only mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) was correlated (p < 0.05) with parent DEHP and appeared to be a more reliable marker of DEHP impact than the monoester.
Показать больше [+] Меньше [-]Carbon emission from global hydroelectric reservoirs revisited Полный текст
2014
Li, Siyue | Zhang, Quanfa
Substantial greenhouse gas (GHG) emissions from hydropower reservoirs have been of great concerns recently, yet the significant carbon emitters of drawdown area and reservoir downstream (including spillways and turbines as well as river reaches below dams) have not been included in global carbon budget. Here, we revisit GHG emission from hydropower reservoirs by considering reservoir surface area, drawdown zone and reservoir downstream. Our estimates demonstrate around 301.3 Tg carbon dioxide (CO₂)/year and 18.7 Tg methane (CH₄)/year from global hydroelectric reservoirs, which are much higher than recent observations. The sum of drawdown and downstream emission, which is generally overlooked, represents 42 % CO₂and 67 % CH₄of the total emissions from hydropower reservoirs. Accordingly, the global average emissions from hydropower are estimated to be 92 g CO₂/kWh and 5.7 g CH₄/kWh. Nonetheless, global hydroelectricity could currently reduce approximate 2,351 Tg CO₂eq/year with respect to fuel fossil plant alternative. The new findings show a substantial revision of carbon emission from the global hydropower reservoirs.
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