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Toxicities of oils, dispersants and dispersed oils to algae and aquatic plants: Review and database value to resource sustainability 全文
2013
Lewis, Michael | Pryor, Rachel
Phytotoxicity results are reviewed for oils, dispersants and dispersed oils. The phytotoxicity database consists largely of results from a patchwork of reactive research conducted after oil spills to marine waters. Toxicity information is available for at least 41 crude oils and 56 dispersants. As many as 107 response parameters have been monitored for 85 species of unicellular and multicellular algae, 28 wetland plants, 13 mangroves and 9 seagrasses. Effect concentrations have varied by as much as six orders of magnitude due to experimental diversity. This diversity restricts phytotoxicity predictions and identification of sensitive species, life stages and response parameters. As a result, evidence-based risk assessments for most aquatic plants and petrochemicals and dispersants are not supported by the current toxicity database. A proactive and experimentally-consistent approach is recommended to provide threshold toxic effect concentrations for sensitive life stages of aquatic plants inhabiting diverse ecosystems.
显示更多 [+] 显示较少 [-]Source contributions to carbonaceous species in PM2.5 and their uncertainty analysis at typical urban, peri-urban and background sites in southeast China 全文
2013
Niu, Zhenchuan | Wang, Sen | Chen, Jinsheng | Zhang, Fuwang | Chen, Xiaoqiu | He, Chi | Lin, Lifeng | Yin, Liqian | Xu, Lingling
Determination of 14C and levoglucosan can provide insights into the quantification of source contributions to carbonaceous aerosols, yet there is still uncertainty on the partitioning of organic carbon (OC) into biomass burning OC (OCbb) and biogenic emission OC (OCbio). Carbonaceous species, levoglucosan and 14C in PM2.5 were measured at three types of site in southeast China combined with Latin hypercube sampling, with the objectives to study source contributions to total carbon (TC) and their uncertainties, and to evaluate the influence of levoglucosan/OCbb ratios on OCbb and OCbio partitioning. It was found reliably that fossil fuel combustion is the main contributor (62.90–72.23%) to TC at urban and peri-urban sites. Biogenic emissions have important contribution (winter, 52.98%; summer, 45.71%) to TC at background site. With the increase in levoglucosan/OCbb ratios, the contribution of OCbio is increased while OCbb is decreased in a pattern of approximate natural logarithm at a given range.
显示更多 [+] 显示较少 [-]Distributions, sources and pollution status of 17 trace metal/metalloids in the street dust of a heavily industrialized city of central China 全文
2013
Li, Zhonggen | Feng, Xinbin | Li, Guanghui | Bi, Xiangyang | Zhu, Jianming | Qin, Haibo | Dai, Zhihui | Liu, Jinling | Li, Qiuhua | Sun, Guangyi
A series of representative street dust samples were collected from a heavily industrialized city, Zhuzhou, in central China, with the aim to investigate the spatial distribution and pollution status of 17 trace metal/metalloid elements. Concentrations of twelve elements (Pb, Zn, Cu, Cd, Hg, As, Sb, In, Bi, Tl, Ag and Ga) were distinctly amplified by atmospheric deposition resulting from a large scale Pb/Zn smelter located in the northwest fringe of the city, and followed a declining trend towards the city center. Three metals (W, Mo and Co) were enriched in samples very close to a hard alloy manufacturing plant, while Ni and Cr appeared to derive predominantly from natural sources. Other industries and traffic had neglectable effects on the accumulation of observed elements. Cd, In, Zn, Ag and Pb were the five metal/metalloids with highest pollution levels and the northwestern part of city is especially affected by heavy metal pollution.
显示更多 [+] 显示较少 [-]Diasteroisomer and enantiomer-specific profiles of hexabromocyclododecane and tetrabromobisphenol A in an aquatic environment in a highly industrialized area, South China: Vertical profile, phase partition, and bioaccumulation 全文
2013
He, Ming-Jing | Luo, Xiao-Jun | Yu, Le-Huan | Wu, Jiang-Ping | Chen, She-Jun | Mai, Bi-Xian
Tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) were determined in water, sediments, sediment cores, and three fish species from a river running through a highly industrialized area in South China. TBBPA concentrations exceeded those of HBCDs in the sediment and the dissolved phase of water and its levels in fish were at the high end of worldwide figures. 26% of HBCDs and 99% of TBBPA were found in dissolved phase of water. Plecostomus occupying high trophic level exhibited higher HBCD levels and higher abundance of α-HBCD than mud carp and nile tilapia which occupy low trophic level. An enrichment of (+)-α-HBCD in three fish species but (−)-α-HBCD in sediment was observed. As for γ-HBCD, most of sediment exhibited racemic while a species-dependence in fish sample was found. No clear trend was found for vertical distribution of enantiomeric profile for γ-HBCD, suggesting that the enantioselectivity of degradation of γ-HBCD is limited.
显示更多 [+] 显示较少 [-]Enhancing the biodegradation of oil in sandy sediments with choline: A naturally methylated nitrogen compound 全文
2013
Mortazavi, Behzad | Horel, Agota | Anders, Jennifer S. | Mirjafari, Arsalan | Beazley, Melanie J. | Sobecky, Patricia A.
We investigated how additions of choline, a naturally occurring methylated nitrogen-containing compound, accelerated hydrocarbon degradation in sandy sediments contaminated with moderately weathered crude oil (4000 mg kg−1 sediment). Addition of lauroylcholine chloride (LCC) and tricholine citrate (TCC) to oil contaminated sediments resulted in 1.6 times higher hydrocarbon degradation rates compared to treatments without added choline derivatives. However, the degradation rate constant for the oil contaminated sediments amended with LCC was similar to that in contaminated sediments amended with inorganic nitrogen, phosphorus, and glucose. Additions of LLC and TCC to sediments containing extensively weathered oil also resulted in enhanced mineralization rates. Cultivation-free 16S rRNA analysis revealed the presence of an extant microbial community with clones closely related to known hydrocarbon degraders from the Gammaproteobacteria, Alphaproteobacteria, and Firmicutes phyla. The results demonstrate that the addition of minimal amounts of organic compounds to oil contaminated sediments enhances the degradation of hydrocarbons.
显示更多 [+] 显示较少 [-]Placental IGF-1 and IGFBP-3 expression correlate with umbilical cord blood PAH and PBDE levels from prenatal exposure to electronic waste 全文
2013
Xu, Xijin | Yekeen, Taofeek Akangbe | Xiao, Qiongna | Wang, Yuangping | Lu, Fangfang | Huo, Xia
Electronic waste recycling produces Polycyclic Aromatic Hydrocarbons (PAHs) and Polybrominated Diphenyl Ethers (PBDEs) which may affect fetal growth and development by altering the insulin-like-growth factor (IGF) system. Questionnaires were administered to pregnant women (Guiyu, an e-waste site, n = 101; control, n = 53), and umbilical cord blood (UCB) and placentas were collected upon delivery. PBDEs and PAHs in UCB and placental IGF-1 and IGFBP-3 mRNA levels were analyzed using GC–MS and real-time PCR, respectively. Infant birth length and Apgar scores were lower in Guiyu. All PAHs (except Fl, Chr, IP, BbF and BP), total 16-PAHs, total/individual PBDEs, placental IGF-1 (median 0.23 vs 0.19; P < 0.05) and IGFBP-3 (median 1.91 vs 0.68; P < 0.001) levels were significantly higher in Guiyu. Spearman correlation showed that BDE-154, BDE-209 and ∑5ring-PAHs positively correlate with IGF-1 while PBDEs, 4 rings and total PAHs correlate with IGFBP-3 expression. Increased placental IGF-1 level might indirectly affect fetal growth and development.
显示更多 [+] 显示较少 [-]Measurement of humic-like substances in aerosols: A review 全文
2013
Zheng, Guangjie | He, Kebin | Duan, Fengkui | Cheng, Yuan | Ma, Yongliang
Aerosol-phase humic-like substances (HULIS) have received increasingly attention due to their universal ambient presence, active participation in atmospheric chemistry and important environmental and health effects. In last decade, intensive field works have promoted development of quantification and analysis method, unearthed spatio-temporal variation, and proved evidence for source identification of HULIS. These important developments were summarized in this review to provide a global perspective of HULIS. The diverse operational HULIS definitions were gradually focused onto several versions. Although found globally in Europe, Asia, Australasia and North America, HULIS are far more typical in continental and near-ground aerosols. HULIS concentrations varied from <1 μg/m3 to >13 μg/m3, with their carbon fraction making up 9%–72% of water soluble organic carbon. Dominant HULIS source was suggested as secondary processes and biomass burning, with the detailed formation pathways suggested and verified in laboratory works.
显示更多 [+] 显示较少 [-]Photosynthetic traits of Siebold's beech and oak saplings grown under free air ozone exposure in northern Japan 全文
2013
Watanabe, Makoto | Hoshika, Yasutomo | Inada, Naoki | Wang, Xiaona | Mao, Qiaozhi | Koike, Takayoshi
We set up a free-air ozone (O3) exposure system for determining the photosynthetic responses of Siebold's beech (Fagus crenata) and oak (Quercus mongolica var. crispula) to O3 under field conditions. Ten-year-old saplings of beech and oak were exposed to an elevated O3 concentration (60 nmol mol−1) during daytime from 6 August to 11 November 2011. Ozone significantly reduced the net photosynthetic rate in leaves of both species in October, by 46% for beech and 15% for oak. In beech there were significant decreases in maximum rate of carboxylation, maximum rate of electron transport in photosynthesis, nitrogen content and photosynthetic nitrogen use efficiency, but not in oak. Stomatal limitation of photosynthesis was unaffected by O3. We therefore concluded photosynthesis in beech is more sensitive to O3 than that in oak, and the O3-induced reduction of photosynthetic activity in beech was due not to stomatal closure, but to biochemical limitation.
显示更多 [+] 显示较少 [-]Identifying potential sources of variability between vegetation carbon storage estimates for urban areas 全文
2013
Davies, Zoe G. | Dallimer, Martin | Edmondson, Jill L. | Leake, Jonathan R. | Gaston, Kevin J.
Although urbanisation is a major cause of land-use change worldwide, towns and cities remain relatively understudied ecosystems. Research into urban ecosystem service provision is still an emerging field, yet evidence is accumulating rapidly to suggest that the biological carbon stores in cities are more substantial than previously assumed. However, as more vegetation carbon densities are derived, substantial variability between these estimates is becoming apparent. Here, we review procedural differences evident in the literature, which may be drivers of variation in carbon storage assessments. Additionally, we quantify the impact that some of these different approaches may have when extrapolating carbon figures derived from surveys up to a city-wide scale. To understand how/why carbon stocks vary within and between cities, researchers need to use more uniform methods to estimate stores and relate this quantitatively to standardised ‘urbanisation’ metrics, in order to facilitate comparisons.
显示更多 [+] 显示较少 [-]Reduction in the earthworm metabolomic response after phenanthrene exposure in soils with high soil organic carbon content 全文
2013
McKelvie, Jennifer R. | Åslund, Melissa Whitfield | Celejewski, Magda A. | Simpson, Andre J. | Simpson, Myrna J.
We evaluated the correlation between soil organic carbon (OC) content and metabolic responses of Eisenia fetida earthworms after exposure to phenanthrene (58 ± 3 mg/kg) spiked into seven artificial soils with OC contents ranging from 1 to 27% OC. Principal component analysis of 1H nuclear magnetic resonance (NMR) spectra of aqueous extracts identified statistically significant differences in the metabolic profiles of control and phenanthrene-exposed E. fetida in the 1% OC soil only. Partial least squares analysis identified a metabolic response in the four soils with OC values ≤11% which was well correlated to estimated phenanthrene porewater concentrations. The results suggest that the higher sorption capability of high OC soils decreased the bioavailability of phenanthrene and the subsequent metabolic response of E. fetida.
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