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Evaluation of metal contamination in the Mand River delta, Persian Gulf Full text
2017
Pourkerman, Majid | Amjadi, Sedigheh | Beni, Abdolmajid Naderi | Lahijani, Hamid | Mehdinia, Ali
Mand River is one of four permanent rivers flowing into the Persian Gulf. Intense industrial activities have significantly impacted its watershed and estuary. In order to evaluate metal contamination and their provenance nine sediment samples were taken from the Mand Delta. Enrichment factors were employed to detect anthropogenic contributions to levels of metal pollution. We also calculated weathering indices in order to identify the source of the metals, related to geological units. Pollution levels were assessed using the modified degree of contamination. Geological units, oil combustion, aerosols and industrial activities are the main factors controlling the abundance of Cr, As, Ni and Pb. Wave action, coastal currents, grain-size parameters, mineralogy, bio-accommodation and organic matter are the factors affecting the distribution and concentration of metals in the study area. More studies are needed to evaluate the impact of metal pollution on the fisheries industry and public health.
Show more [+] Less [-]Quantifying the particulate matter accumulation on leaf surfaces of urban plants in Beijing, China Full text
2017
Shi, Junna | Zhang, Gang | An, Hailong | Yin, Weilun | Xia, Xinli
Particulate matter is potentially harmful to human health but green tree species act as air filters to adhere these particulates. The elemental composition, number density, and size fractions of particles on leaf surfaces of 14 urban green from Xizhimen overpass and the Olympic Forest Park in Beijing, China were examined by scanning electron microscopy and X-ray energy dispersive spectrometry. Particles that accumulated on leaves were comprised mainly of C, O, Si, Ca, Fe, and Pb. The number density of particles was 50,961.5 mm−2, and 52.9% and 25% of the particles were submicron (<1 μm) and fine (<2.5 μm), respectively. The densities and size fractions of the particles deposited on the adaxial and abaxial side of leaves were significantly different, and 24% of the particles were deposited on the abaxial side of leaves. The densities of the particles in four size fractions differed significantly among the species at the two sampling sites. Salix matsudana, Euonymus japonicus, Magnolia denudate, Sophora japonica, Amygdalus persica, and Salix babylonica efficiently captured all particle sizes on their leaf surfaces. S. matsudana, E. japonicus, M. denudate, S. japonica, Fraxinus chinensis, and Ginkgo biloba efficiently captured submicron and fine particles, which can have serious effects on human health. These differences among species provide more insight into the sink capacity of green tree species, and the efficiencies of plant species for trapping particulates can be used to guide urban tree planning and decrease air pollution.
Show more [+] Less [-]Factors influencing the diurnal atmospheric concentrations and soil-air exchange of PBDEs at an e-waste recycling site in China Full text
2017
Wang, Yan | Hou, Minmin | Zhao, Hongxia | Zhang, Qiaonan | Wu, Xiaowei
Factors influencing the diurnal atmospheric concentrations and soil-air exchange of polybrominated diphenyl ethers (PBDEs) were investigated at an e-waste recycling site in China during winter and summer. Total PBDE concentrations in winter and summer were 11.0–42.4 and 120–431 pg/m3 in the gaseous phase and 13.3–234 and 69.0–208 pg/m3 in the particulate phase, respectively. Total PBDE concentrations in the e-waste contaminated and nearby soils were 869 and 611 ng/g in winter and 2130 and 31 ng/g in summer, respectively. Concentrations in the gaseous phase were significantly higher in summer than in winter, but concentrations in the particle phase were comparable between winter and summer. Because of the influence of occasional accidental inputs, no apparent diurnal variations were found for PBDEs in either the particle or gaseous phase. Both temperatures and local emissions affected air concentrations of PBDEs in this area. The estimated directions of soil-air exchange of PBDEs suggest that the e-waste contaminated soil generally acted as a secondary source of several low brominated PBDEs, while the nearby soil acted as a secondary source of BDE28. The diurnal variation of atmospheric concentrations of PBDEs is not strong enough to alter the soil-air exchange direction.
Show more [+] Less [-]Determination and assessment of phthalate esters content in sediments from Kaohsiung Harbor, Taiwan Full text
2017
Chen, Chih-Feng | Chen, Chiu-Wen | Ju, Yun-Ru | Dong, Cheng-Di
Phthalate esters (PAEs) are known organic endocrine disruptors. The distribution of 10 PAEs in sediments of Kaohsiung Harbor of Taiwan was studied using organic solvents extraction and quantified by gas chromatography/mass spectrometry. The average concentration of total PAEs (ΣPAEs) in the sediment was 8713±11,454ng/g dw with di-(2-ethylhexyl) phthalate (DEHP) (3630ng/g-dw) and diisononyl phthalate (DiNP) (3497ng/g dw) being the major species, which constitutes of 41.7% and 40.1% of ΣPAEs. PAEs concentration was relatively high near the river mouths, especially in Love River mouth, and diminished toward the harbor. Based on the sediment quality guidelines developed from previous studies, several of the observed PAE levels exceeded the Maximum Contaminant Level, especially for DEHP and thus may cause adverse effect in aquatic organisms.
Show more [+] Less [-]Effects of high salinity from desalination brine on growth, photosynthesis, water relations and osmolyte concentrations of seagrass Posidonia australis Full text
2017
Cambridge, M L | Zavala-Perez, A | Cawthray, G R | Mondon, J | Kendrick, G A
Highly saline brines from desalination plants expose seagrass communities to salt stress. We examined effects of raised salinity (46 and 54psu) compared with seawater controls (37psu) over 6weeks on the seagrass, Posidonia australis, growing in tanks with the aim of separating effects of salinity from other potentially deleterious components of brine and determining appropriate bioindicators. Plants survived exposures of 2–4weeks at 54psu, the maximum salinity of brine released from a nearby desalination plant. Salinity significantly reduced maximum quantum yield of PSII (chlorophyll a fluorescence emissions). Leaf water potential (Ψw) and osmotic potential (Ψπ) were more negative at increased salinity, while turgor pressure (Ψp) was unaffected. Leaf concentrations of K+ and Ca2+ decreased, whereas concentrations of sugars (mainly sucrose) and amino acids increased. We recommend leaf osmolarity, ion, sugar and amino acid concentrations as bioindicators for salinity effects, associated with brine released in desalination plant outfalls.
Show more [+] Less [-]Unsustainable human-induced injuries to the Critically Endangered Taiwanese humpback dolphins (Sousa chinensis taiwanensis) Full text
2017
Wang, John Y. | Riehl, Kimberly N. | Yang, Shih-Chu | Araújo-Wang, Claryana
The Critically Endangered Taiwanese humpback dolphin (Sousa chinensis taiwanensis) is endemic to inshore and estuarine waters of central western Taiwan. It numbers fewer than 75 individuals, is declining and faces a myriad of human threats. Data from a long-term photo-identification program on these dolphins allowed major injuries to be examined quantitatively. A large proportion (57.7%) of individuals had suffered major human-induced injuries that likely compromised their health, survivorship or reproductive potential and thus, the future of this subspecies. Considering major injuries as “takes”, the injury rate (1.13 dolphins/year) for the population was 8–8.5 times higher than its Potential Biological Removal rate. Observations of new injuries and fishing gear entanglements on several dolphins showed that fisheries continue to be the predominant cause of these major injuries. Unless immediate action is taken to reduce harmful fisheries, extinction is imminent for Taiwan's only endemic dolphin.
Show more [+] Less [-]An experimental investigation of underwater spread of oil spill in a shear flow Full text
2017
Zhu, Hongjun | You, Jiahui | Zhao, Honglei
The time taken for spilt oil to appear firstly at the sea surface and its location are two key issues for emergency response. The underwater spread of oil spill in a shear flow was studied experimentally in a re-circulating water channel. The high speed imaging technology was employed to record the whole transport process of oil spilt from a leak of a submarine pipe to the surface. Based on the experimental results, three underwater transport types are identified, which are single droplet pattern (model A), linear chain pattern (model B) and oil plume pattern (model C), respectively. The pressure difference inside and outside of the leak determines the underwater transport pattern. For single droplet pattern, the transport of oil droplet has two successive stage, namely the accumulation stage and the buoyant droplet stage. When it comes to linear chain pattern, the first stage changes to be the initial jet stage. Besides the initial jet stage and the buoyant droplet stage, oil plume pattern has an intermediate transition stage, namely the plume development stage. During the whole floating process, the pressure difference dominates the initial stage, while droplet buoyancy is the driven force in the rest. The required time for oil droplets to reach the surface is increased with the decreasing of the initial momentum and the increasing of the shear flow velocity. In the buoyance dominated stage, the floating rate of oil droplets is basically unchanged and the horizontal migration rate is similar with the shear flow velocity. Both the break-up and coalescence of oil droplets have two forms, which are single droplet splitting and droplet-column separation for break-up form and turbulence merging and pursuit merging for coalescence form, respectively.
Show more [+] Less [-]Potential risk assessment of metals in edible fish species for human consumption from the Eastern Aegean Sea Full text
2017
Pazi, Idil | Gonul, L Tolga | Kucuksezgin, Filiz | Avaz, Gulsen | Tolun, Leyla | Unluoglu, Aydın | Karaaslan, Yakup | Gucver, S Mine | Koc Orhon, Aybala | Siltu, Esra | Olmez, Gulnur
The levels of Hg, Cd, Pb, Cr, Cu and Zn were measured in the tissues of four edible fish species namely: Diplodus annularis, Pagellus erythrinus, Merluccius merluccius and Mullus barbatus, collected from the Turkish Coast of the Aegean Sea. Except for D. annularis, the levels of Cd and Pb in all fish tissues sampled in Aliaga Bay in 2009 were above the tolerable limits according to the Food and Agriculture Organization of the United Nations (FAO). Hg in P. erythrinus and M. barbatus were higher than the maximum permitted limits (FAO), while D. annularis and M. merluccius were lower than the limit for biota in the district of Aliaga. Although the Target Hazard Quotient (THQ) values for Cd, Pb, Cu, Cr, Zn in all fish samples were lower than 1.0, the THQ for Hg levels were higher than 1.0 for most of the samples. According to the THQ values, M. merluccius may be consumed in moderation from Aliaga Bay, while the consumption of M. barbatus and P. erythrinus collected from Aliaga Bay are potentially hazardous to human health due to the Hg concentrations. Fish collected from Izmir Bay can be consumed safely.
Show more [+] Less [-]Tree bark as bioindicator of metal accumulation from road traffic and air quality map: A case study of Chiang Mai, Thailand Full text
2017
Janta, Rungruang | Chantara, Somporn
Trees have been recognized as air quality bioindicators, but they have still not been fully implemented in tropical areas. In this study, bark of Cassia fistula was used to inspect accumulation of air pollutants (metals) emitted from road traffic in the city of Chiang Mai, Thailand. The mean concentrations of metal accumulated on tree bark (ng/cm2) in descending order were Al (1,238) > Fe (707) > Zn (162) » Cu (21.1) » Pb (6.37) > Cr (2.14). Correlations of Enrichment Factors: EFTS (metal concentrations on bark compared to those in soil) among metals were relatively strong (r > 0.6) meaning that they were probably generated from the same sources. Moreover, principal component analysis and cluster analysis of EFTS values revealed that Al and Fe were generated from soil resuspension that were attached on vehicle wheels and on road surfaces, while Cr, Cu, Pb and Zn resulted directly from vehicle emissions. The results lead to the conclusion that tree bark is a good bioindicator for air pollutant accumulation in this area. In addition, pollution indices, including total geoaccumulation index (IGEO-tot) and pollution load index (PLI), were applied to generate air quality maps of the city. The maps illustrated that the most polluted areas in the city are the areas that have high traffic volume and building density, in which hospitals and schools are located. The degree of pollution presented in each area was influenced by both road traffic volume and density of buildings in relation to air ventilation capacity.
Show more [+] Less [-]Commuter exposure to particulate matter for different transportation modes in Xi'an, China Full text
2017
Qiu, Zhaowen | Song, Jianhua | Xu, Xiaoqin | Luo, Yaping | Zhao, Ruini | Zhou, Wencai | Xiang, Bihai | Hao, Yanzhao
Toxic air pollution on city streets is a very important issue, as pollutants are associated with adverse health effects, including respiratory and cardiovascular diseases. This study compared commuters' exposures to inhalable suspended particulate matter (PM) for different transportation modes in Xi'an City, China. Four commuting modes—private car, subway, bus and walking—were selected for the study. Commuter exposure concentrations to PM (PM10, PM2.5, PM1.0) were investigated in the following microenvironments: private cars under four ventilation modes, subway trains and station platforms, buses under two different ventilation modes, and pedestrians. Pearson correlation analysis was used to analyze the relationships between commuter PM10, PM2.5 and PM1.0 exposure concentrations under the different commuting modes. A mixed-effect linear model was used to identify the effects of different commuting modes on PM mass and number concentrations in these different traffic microenvironments. The results indicated that the concentration of particulate matter (PM) is significantly influenced by transportation mode as well as by vehicle ventilation systems. Among the four commuting modes, commuters were exposed to the lowest concentrations of PM10 (11.83 ± 7.60 μg m−3), PM2.5 (10.09 ± 6.63 μg m−3) and PM1.0 (9.52 ± 6.17 μg m−3) in a private car with air conditioning recirculation. In contrast, passengers waiting for a train on a subway station platform were exposed to the highest PM concentrations (244.99 ± 43.19 μg m−3). Size fractions of PM differed greatly across PM exposures with the ratio of fine particles to coarser particles (PM2.5/PM10) varying from 45 to 96%.
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