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Food preferences and Hg distribution in Chelonia mydas assessed by stable isotopes 全文
2015
Bezerra, M.F. | Lacerda, L.D. | Rezende, C.E. | Franco, M.A.L. | Almeida, M.G. | Macêdo, G.R. | Pires, T.T. | Rostán, G. | Lopez, G.G.
Mercury (Hg) is a highly toxic pollutant that poses in risk several marine animals, including green turtles (Chelonia mydas). Green turtles are globally endangered sea turtle species that occurs in Brazilian coastal waters as a number of life stage classes (i.e., foraging juveniles and nesting adults). We assessed total Hg concentrations and isotopic signatures (13C and 15N) in muscle, kidney, liver and scute of juvenile green turtles and their food items from two foraging grounds with different urban and industrial development. We found similar food preferences in specimens from both areas but variable Hg levels in tissues reflecting the influence of local Hg backgrounds in food items. Some juvenile green turtles from the highly industrialized foraging ground presented liver Hg levels among the highest ever reported for this species. Our results suggest that juvenile foraging green turtles are exposed to Hg burdens from locally anthropogenic activities in coastal areas.
显示更多 [+] 显示较少 [-]Distribution and elevated soil pools of mercury in an acidic subtropical forest of southwestern China 全文
2015
Zhou, Jun | Wang, Zhangwei | Zhang, Xiaoshan | Chen, Jian
Tieshanping catchment in southwest China was supposed to a large pool of atmospheric mercury. This work was aimed to examine THg (total mercury) concentrations, pools and influence factors in the acidic forest. THg concentrations were highly elevated in the study area, which was significantly depended on TOM (total organic matter) concentrations and altitudinal elevation, whereas negatively correlated with soil pH. The pools of mercury accumulated in soils were correlated strongly with the stocks of TOM and altitude, ranged from 5.9 to 32 mg m−2 and averaged 14.5 mg m−2, indicating that the acidic forest was a great sink of atmospheric mercury in southwest China. THg concentrations in stream waters decreased with altitude increasing and regression analyses showed that soil/air exchange flux would be increased with the decrease of altitude. Present results suggest that elevation increasing decreases THg losses as low THg concentrations in runoffs and volatilization from soils.
显示更多 [+] 显示较少 [-]Fullerenes(nC60) affect the growth and development of the sediment-dwelling invertebrate Chironomus riparius larvae 全文
2015
Waissi-Leinonen, Greta C. | Nybom, Inna | Pakarinen, Kukka | Akkanen, Jarkko | Leppänen, Matti T. | Kukkonen, Jussi V.K.
The possible toxicity of nanoparticles (NPs) to aquatic organisms needs to be investigated for chronic effects at low concentrations. Chronic effects of carbon NPs, fullerenesC60, on the midges of Chironomus riparius at different life stages on larvae and adult midges were investigated. Sediment associated fullerenesC60 were studied by 10-day growth and 42-day emergence tests with artificial sediment at nominal concentration ranges 0.0004–80 mg/kg dry weight. The body length decreased in the lower tested concentrations (0.0025–20 mg/kg), but the effect vanished with higher concentrations. Delayed emergence rate observed at 0.5 mg/kg. The observed effects correlated with analyzed sediment particle sizes indicating that small agglomerates of fullerene have more significant effects on C. riparius than larger agglomerates observed with higher C60 doses. The results reveal that fullerene may pose risks to benthic organisms, emerging as changes in the ecotoxic parameters studied here which inflects by the survival of the population.
显示更多 [+] 显示较少 [-]A statistical model for determining impact of wildland fires on Particulate Matter (PM2.5) in Central California aided by satellite imagery of smoke 全文
2015
Preisler, Haiganoush K. | Schweizer, Donald | Cisneros, Ricardo | Procter, Trent | Ruminski, Mark | Tarnay, Leland
As the climate in California warms and wildfires become larger and more severe, satellite-based observational tools are frequently used for studying impact of those fires on air quality. However little objective work has been done to quantify the skill these satellite observations of smoke plumes have in predicting impacts to PM2.5 concentrations at ground level monitors, especially those monitors used to determine attainment values for air quality under the Clean Air Act. Using PM2.5 monitoring data from a suite of monitors throughout the Central California area, we found a significant, but weak relationship between satellite-observed smoke plumes and PM2.5 concentrations measured at the surface. However, when combined with an autoregressive statistical model that uses weather and seasonal factors to identify thresholds for flagging unusual events at these sites, we found that the presence of smoke plumes could reliably identify periods of wildfire influence with 95% accuracy.
显示更多 [+] 显示较少 [-]Nano silver and nano zinc-oxide in surface waters – Exposure estimation for Europe at high spatial and temporal resolution 全文
2015
Dumont, Egon | Johnson, Andrew C. | Keller, Virginie D.J. | Williams, Dick (Richard J.)
Nano silver and nano zinc-oxide monthly concentrations in surface waters across Europe were modeled at ∼6 × 9 km spatial resolution. Nano-particle loadings from households to rivers were simulated considering household connectivity to sewerage, sewage treatment efficiency, the spatial distribution of sewage treatment plants, and their associated populations. These loadings were used to model temporally varying nano-particle concentrations in rivers, lakes and wetlands by considering dilution, downstream transport, water evaporation, water abstraction, and nano-particle sedimentation. Temporal variability in concentrations caused by weather variation was simulated using monthly weather data for a representative 31-year period. Modeled concentrations represent current levels of nano-particle production. Two scenarios were modeled. In the most likely scenario, half the river stretches had long-term average concentrations exceeding 0.002 ng L−1 nano silver and 1.5 ng L−1 nano zinc oxide. In 10% of the river stretches, these concentrations exceeded 0.18 ng L−1 and 150 ng L−1, respectively. Predicted concentrations were usually highest in July.
显示更多 [+] 显示较少 [-]Detecting the sensitivity of magnetic response on different pollution sources – A case study from typical mining cities in northwestern China 全文
2015
Wang, Bo | Xia, Dunsheng | Yu, Ye | Jia, Jia | Nie, Yan | Wang, Xin
Rapid monitoring and discriminating different anthropogenic pollution is a key scientific issue. To detect the applicability and sensitivity of magnetic measurements for evaluating different industrial pollution in urban environment, characteristics of topsoil from three typical fast developing industrial cities (Jinchang, Baiyin and Jiayuguan in Gansu province, northwestern China) were studied by magnetic and geochemical analyses. The results showed that magnetic susceptibility was enhanced near industrial areas, and PSD-MD magnetite dominated the magnetic properties. Magnetic concentration parameters (χlf, SIRM, and χARM) showed different correlations with heavy metals and PLI in the three cities, indicating significantly different magnetic response to different pollution sources. Principal component analysis showed that ferrimagnetic minerals coexist with heavy metals of Fe, As, Cu, Pb, and Zn in Baiyin and Fe, V, Cu, Mn, Pb, and Cr in Jiayuguan. Fuzzy cluster analysis and regression analysis further indicated that the sensitivity of magnetic monitoring to fuel dust is higher than that to mineral dust near non-ferrous metal smelters, and fossil fuel consumption is an important factor for increasing magnetite content. In all the three cities, the sensitivity of magnetic monitoring to pollutants from steel plants is much higher than that from non-ferrous metal plants. Therefore, magnetic proxies provide a rapid means for detecting heavy metal contamination caused by multi-anthropogenic pollution sources in a large scale area, however, the sensitivity was controlled by pollution sources.
显示更多 [+] 显示较少 [-]Increase in polycyclic aromatic hydrocarbon (PAH) emissions due to briquetting: A challenge to the coal briquetting policy 全文
2015
Chen, Yingjun | Zhi, Guorui | Feng, Yanli | Chongguo Tian, | Bi, Xinhui | Li, Jun | Zhang, Gan
Both China and UNEP recommend replacing raw coal chunks with coal briquettes in household sector as clean coal technology (CCT), which has been confirmed by the decreased emissions of particulate matter and black carbon. However, the clean effect has never been systematically checked by other pollutants like polycyclic aromatic hydrocarbons (PAHs). In this study, 5 coals with different geological maturities were processed as both chunks and briquettes and burned in 3 typical coal stoves for the measurement of emission factors (EFs) of particle-bound PAHs. It was found that the EFs of 16 parent PAHs, 26 nitrated PAHs, 6 oxygenated PAHs, and 8 alkylated PAHs for coal briquettes were 6.90 ± 7.89, 0.04 ± 0.03, 0.65 ± 0.40, and 72.78 ± 18.23 mg/kg, respectively, which were approximately 3.1, 3.7, 1.9, and 171 times those for coal chunks, respectively. Such significant increases in PAH emissions increased human health risk and challenged the policy of CCT.
显示更多 [+] 显示较少 [-]Characterizations of wet mercury deposition on a remote high-elevation site in the southeastern Tibetan Plateau 全文
2015
Huang, Jie | Kang, Shichang | Zhang, Qianggong | Guo, Junming | Sillanpää, Mika | Wang, Yongjie | Sun, Shiwei | Sun, Xuejun | Tripathee, Lekhendra
Accurate measurements of wet mercury (Hg) deposition are critically important for the assessment of ecological responses to pollutant loading. The Hg in wet deposition was measured over a 3-year period in the southeastern Tibetan Plateau. The volume-weighted mean (VWM) total Hg (HgT) concentration was somewhat lower than those reported in other regions of the Tibetan Plateau, but the VWM methyl-Hg concentration and deposition flux were among the highest globally reported values. The VWM HgT concentration was higher in non-monsoon season than in monsoon season, and wet HgT deposition was dominated by the precipitation amount rather than the scavenging of atmospheric Hg by precipitation. The dominant Hg species in precipitation was mainly in the form of dissolved Hg, which indicates the pivotal role of reactive gaseous Hg within-cloud scavenging to wet Hg deposition. Moreover, an increasing trend in precipitation Hg concentrations was synchronous with the recent economic development in South Asia.
显示更多 [+] 显示较少 [-]Effect of biochar aging on surface characteristics and adsorption behavior of dialkyl phthalates 全文
2015
Ghaffar, Abdul | Ghosh, Saikat | Li, Fangfang | Dong, Xudong | Zhang, Di | Wu, Min | Li, Hao | Pan, Bo
The implications of biochar aging regarding their material properties as well as their interactions with other contaminants are not vivid. We report the role of biochar aging on sorption behavior of di-alkyl phthalates (PAEs). Biochars used in this study were produced from peanut-shell and their aging was simulated by chemical oxidation. The structural composition and morphology of the obtained biochars, before and after oxidation with HNO3/H2SO4, were analyzed by element composition, XPS, DRIFT, and SEM/EDX. Several experimental results unequivocally showed oxygen enrichment in the mixed acid treated samples compared to their precursors. Despite surface area reduction and pore destruction, increased PAEs sorption on oxidized biochar surfaces portrayed existence of strong PAEs binding sites. The adsorption of PAEs on oxidized biochar surface is a cumulative influence of hydrophobic interactions and pi–pi electron donor–acceptor interactions. Our results suggest that imminent aging of biochar upon environmental exposure may change their sorbent properties.
显示更多 [+] 显示较少 [-]Organophosphorus flame retardants and plasticizers in the aquatic environment: A case study of the Elbe River, Germany 全文
2015
Wolschke, Hendrik | Sühring, Roxana | Xie, Zhiyong | Ebinghaus, Ralf
This study reports the occurrence and distribution of organophosphorus flame retardants and plasticizers (OPEs) in the Elbe and Rhine rivers. A special focus of this investigation concerns the potential impacts of a major flood event in 2013 on the OPE patterns and levels in the Elbe River. In this river, 6 of 13 OPEs were detected, with tris-ethyl-phosphate (TEP, 168 ± 44 ng/L), tris-1,3-dichloro-2-propyl-phosphate (TDCPP, 155 ± 14 ng/L) and tris-1-chloro-2-propyl phosphate (TCPP, 126 ± 14 ng/L) identified as the dominant compounds. Relative to previous studies, an increase in the concentrations and relative contributions of TDCPP to the total level of OPEs was observed, which was likely caused by its increased use as a replacement for the technical pentaBDE formulation. During the flood event, the concentrations of OPEs were similar to the normal situation, but the mass fluxes increased by a factor of approximately ten (∼16 kg/d normal versus ∼160 kg/d flood peak). No input hotspots were identified along the transects of the Elbe and Rhine rivers, and the mass flux of OPEs appeared to be driven by water discharge.
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