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Biomass burning emissions contaminate winter snowfalls in urban Beijing: A case study in 2012
2015
You, Chao | Gao, Shaopeng | Xu, Chao
Three monosaccharide anhydrides levoglucosan, mannosan and galactosan were detected in winter snowfall samples of 2012 in urban Beijing. Concentrations of three isomers vary from 0.15 to 54.43ngmL−1, with an average value of 10.49ngmL−1. Levoglucosan is the most abundant component. Winter snowfalls are contaminated by biomass burning emissions seriously in urban Beijing. The main sources are softwood and crop residue burnings around Beijing from late autumn to early winter, while long-range transport of biomass burning emissions contribute more during the late winter. Concentrations of monosaccharide anhydrides in snowfall samples may be affected by both topography and the meteorological conditions around urban Beijing.
显示更多 [+] 显示较少 [-]A three-dimensional water quality model to evaluate the environmental capacity of nitrogen and phosphorus in Jiaozhou Bay, China
2015
Li, Keqiang | Zhang, Li | Li, Yan | Zhang, Longjun | Wang, Xiulin
Jiaozhou Bay has recently suffered from serious problems with pollution and eutrophication. Thus, land-based pollutant load must be reduced through a national control program. In this study, we developed a 3D water quality model to determine the environmental capacity of nitrogen and phosphorus in Jiaozhou Bay. A 3D hydrodynamic model (the estuarine, coastal, and ocean modeling system with sediments) was coupled with a water quality model, which was adapted from the dynamic model of nitrogen and phosphorus for a mesocosm near Jiaozhou Bay. The water quality model is divided into seven components: dissolved inorganic nitrogen, phosphate, phytoplankton, zooplankton, detritus, dissolved organic nitrogen, and dissolved organic phosphorus. Furthermore, it was calibrated based on data collected from Jiaozhou Bay in 2003. The proposed model effectively reproduced the spatiotemporal variability in nutrient concentration, thus suggesting that a reasonable numerical representation of the prototype system must be developed for further evaluation of environmental capacity.
显示更多 [+] 显示较少 [-]Study of chemical characteristics of particulate matter concentrations in Riyadh, Saudi Arabia
2015
Alharbi, Badr | Shareef, Mohammed Mujtaba | Husain, Tahir
Particulate matter samples were collected from several locations during September 2011 and September 2012 in Riyadh, Saudi Arabia. In addition to determining particulate matter (as PM10) concentrations, the samples were analyzed for several metals and ions. PM concentration was approximately 3 times higher than the Country’s ambient air quality standards respectively. Metals and ions contributed to about 21.5% and 16.2% of the PM concentrations respectively. Summer vs. winter comparison showed that PM concentrations were approximately 84% higher in summer and the crustal matter species such as Fe, Mn, Ti, Ca+2, Mg+2 increased several folds in summer, primarily attributed to dust storms. The weekdays PM concentrations were 17% more than the weekend concentrations, indicating weekday activities contribute to the concentrations. The dust storms lead to over 200% increase in the PM and some elements primarily Al, Fe, Mg and Ca. Spatial comparison at industrial and residential locations revealed about 60% increase in PM concentrations and substantial increase in Zn, Mn, B, Mg, Fe, and Al and the ions K+, SO4--, and Cl- at industrial locations. Bivariate correlations among the metals and ions demonstrated that strong correlation existed between Al, Fe, Mg, K and Mn suggesting a common origin for these species i.e. the crustal mineral aerosols. The correlations among cations and anions implied the presence of compounds in the atmosphere such as CaSO4, (NH4)2SO4, KCl, KSO4, and also to some extent MgSO4. An investigation of ionic ratios revealed that ratios SO4-2/NO3-, Ca+2/K+, and Ca+2/Na+ could be possible indicators to identify scenarios industrial over residential locations, storm days over no storm days and summer over winter periods respectively.
显示更多 [+] 显示较少 [-]Residents’ perception of air quality, pollution sources, and air pollution control in Nanchang, China
2015
Liao, Xiong | Tu, Hong | Maddock, Jay E. | Fan, Si | Lan, Guilin | Wu, Yanyan | Yuan, Zhao Kang | Lu, Yuanan
To assess the public's understanding of the main sources of air pollution in Nanchang and factors influencing their perceptions of Nanchang's air quality status, a face–to–face survey data was collected at the provincial children's hospital and four kindergarten classes in Nanchang. A total of 989 parents with children between the ages of 2 to 10 years old participated in the survey. Among which 69% of respondents believed that the current air quality was worse than three years ago. This study reveals that parents who were under 40 years old of age with higher education level and international travel experience, had higher level awareness of air pollution. Men tend to have lower knowledge of air pollution as compared to women. The top three selected sources of air pollution were motor vehicles (78.5%), waste burning (56.3%) and industrial facilities (53.7%). In addition, 79.8% of respondents believed that the government did not spend enough on environmental protection and 96.8% suggested to increase government funding to improve air quality. The majority of respondents (>90%) strongly urges the Nanchang government to prioritize environmental protection. The findings from this study suggest the need for the government to improve the awareness of the main sources of air pollution, especially to residents of rural areas with lower levels of education, to more effectively and efficiently control air pollution in Nanchang.
显示更多 [+] 显示较少 [-]AERONET data–based determination of aerosol types
2015
Tan, Fuyi | Lim, Hwee San | Abdullah, Khiruddin | Yoon, Tiem Leong | Holben, Brent
Aerosols are among the most interesting topics investigated by researchers because of their complicated characteristics and poor quantification. Moreover, significant uncertainties are associated with changes in the Earth's radiation budget. Previous studies have shown numerous difficulties and challenges in quantifying aerosol influences. In addition, the heterogeneity from aerosol loading and properties, including spatial, temporal, size, and composition features, presents a challenge. In this study, we investigated aerosol characteristics over two regions with different environmental conditions and aerosol sources. The study sites are Penang and Kuching in Malaysia, where a ground–based AErosol RObotic NETwork (AERONET) sun–photometer was deployed. The types of aerosol, such as biomass burning, urban/industrial, marine, and dust aerosols, for both study sites were identified by analyzing aerosol optical depth and angstrom exponent. Seasonal monsoon variation results in different aerosol optical properties, characteristics, and types of aerosols that are dominant in Penang and Kuching. Seasonal monsoon flow trend patterns from a seven–day back–trajectory frequency plotted by the Hybrid Single–Particle Lagrangian Integrated Trajectory model illustrated the distinct origins of trans–boundary aerosol sources. Finally, we improved our findings in Malaysian sites using the AERONET data from Singapore and Indonesia. Similarities in the optical properties of aerosols and the distribution types (referred to as homogeneous aerosol) were observed in the Penang–Singapore and the Kuching–Pontianak sites. The dominant aerosol distribution types were completely different for locations in the western (Penang–Singapore) and eastern (Kuching–Pontianak) parts of the South China Sea. This is a result of spatial and temporal heterogeneity. The spatial and temporal heterogeneities for the western and eastern portions of South China Sea provide information on the natural or anthropogenic processes that take place.
显示更多 [+] 显示较少 [-]Integrating science education and marine conservation through collaborative partnerships
2015
Martin, Jeannie Miller | Higgins, Katie | Lee, Kristin | Stearns, Kira | Hunt, Lori
The Georgia Sea Turtle Center has a mission of conservation based rehabilitation, research, and education. Marine debris is a serious threat to marine species. In an effort to educate local students, the GSTC obtained a grant to provide educational opportunities to local third graders. Third and fourth grade classes in Glynn County, Georgia were offered a Garbage in the Water program and 964 students were reached. After programming, students showed a statistically significant (p<.0001) increase in test scores between the pre and posttests. This success led to repeat funding for additional programming for first grades as well as a formalized relationship with the Glynn County School District. As part of this relationship the Georgia Sea Turtle Center is now the official field trip location for all third grades in the district.
显示更多 [+] 显示较少 [-]Composition and potential origin of marine debris stranded in the Western Indian Ocean on remote Alphonse Island, Seychelles
2015
Duhec, Aurélie V. | Jeanne, Richard F. | Maximenko, Nikolai | Hafner, Jan
The abundance, composition, and potential sources of marine debris were investigated on remote Alphonse Island, during the austral winter 2013. A total of 4743 items, weighing 142kg, were removed from 1km of windward beach, facing the prevailing southeasterly trade winds. Our study demonstrates the prevalence of plastic debris as a world-wide marine contaminant. Characteristics of the debris suggest it originated primarily from land-based sources. To determine their potential geographic sources we used the Surface Current from Diagnostic model of near-surface ocean currents, forced by satellite sea level and wind data. While preliminary evidence indicated the Southeast Asia to be the main source of the flotsam, the model highlighted Somalia as another potential primary source. Our study concludes that most of the collected debris entered the sea as a result of inadequate waste management and demonstrates how anthropogenic waste can negatively impact even the most remote environments.
显示更多 [+] 显示较少 [-]Mercury (Hg) speciation in coral reef systems of remote Oceania: Implications for the artisanal fisheries of Tutuila, Samoa Islands
2015
Morrison, R John | Peshut, Peter J. | West, Ronald J. | Lasorsa, Brenda K.
We investigated Hg in muscle tissue of fish species from three trophic levels on fringing reefs of Tutuila (14°S, 171°W), plus water, sediment and turf alga. Accumulation of total Hg in the herbivore Acanthurus lineatus (Acanthuridae, lined surgeonfish, (n=40)) was negligible at 1.05 (±0.04) ngg−1 wet-weight, (∼65% occurring as methyl Hg). The mid-level carnivore Parupeneus spp. (Mullidae, goatfishes (n=10)) had total Hg 29.8 (±4.5) ngg−1 wet-weight (∼99% as methyl Hg). Neither A. lineatus or Parupeneus spp. showed a propensity to accumulate Hg based on body size. Both groups were assigned a status of “un-restricted” for monthly consumption limits for non-carcinogenic health endpoints for methyl Hg. The top-level carnivore Sphyraena qenie (Sphyraenidae, blackfin barracuda, n=3) had muscle tissue residues of 105, 650 and 741ngg−1 wet-weight (100% methyl Hg, with increasing concentration with body mass, suggesting that S. qenie >15kg would have a recommendation of “no consumption”.
显示更多 [+] 显示较少 [-]Relative bioavailability and toxicity of fuel oils leaking from World War II shipwrecks
2015
Faksness, Liv-Guri | Daling, Per | Altin, Dag | Dolva, Hilde | Fosbæk, Bjørn | Bergstrøm, Rune
The Norwegian Authorities have classified 30 WWII shipwrecks to have a considerable potential for pollution to the environment, based on the location and condition of the wreck and the types and amount of fuel. Oil thus far has been removed from eight of these shipwrecks. The water accommodated fractions of oils from two British wrecks and two German wrecks have been studied with special emphasis on chemistry and biological effects (algae growth (Skeletonema costatum) and copepod mortality (Calanus finmarchicus)). Chemical analyses were also performed on three additional German wreck oils. The results from these studies show that the coal based oils from German WWII shipwrecks have higher toxicity to marine organisms than the mineral oils from the British shipwrecks. The potential for higher impact on the marine environment of coal based oils has resulted in an altering of the priority list for oil recovery from WWII wrecks by the authorities.
显示更多 [+] 显示较少 [-]Influence of atmospheric circulation patterns on urban air quality during the winter
2015
Grundstrom, Maria | Tang, Lin | Hallquist, Mattias | Nguyen, Hung | Chen, Deliang | Pleijel, Håkan
Relationships between urban nitrogen dioxide (NO2) and atmospheric circulation at two spatial scales were studied for Southern Sweden. Lamb Weather Types (LWT) describe the circulation (scale: thousands of kilometers) including non–directional (cyclonic and anticyclonic) and directional types depending on the wind direction. LWTs with low wind speeds (anticyclonic, NW and N) were associated with strongly elevated [NO2], between 46–52% of the daily averages of NO2 exceeded the 60μg m−3 air quality standard (AQS) when occurring during these LWTs. The lowest fractions of exceedances of NO2 AQS were generally observed for LWTs E, S, SW and W. A larger scale circulation (several thousands of kilometers) was represented by the North Atlantic Oscillation (NAO) affecting meteorology over middle and high latitudes in the Northern Hemisphere. While a negative NAO index (NAOI) favors stagnant high pressure weather over Northern Europe, a positive NAOI is often associated with windy conditions. High [NO2] was found to be frequent under negative NAOI. Additionally, larger fractions of exceedances of NO2 AQS were observed for the majority of LWTs occurring at negative NAOI. It’s concluded that both LWTs and NAOI had partly independent effects on the urban air quality in a North European city. These circulation indices can be useful tools for air pollution risk assessment and forecasting.
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