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Characteristics and source apportionment of VOCs in the suburban area of Beijing, China Texte intégral
2016
Wang, Gang | Cheng, Shuiyuan | Wei, Wei | Zhou, Ying | Yao, Sen | Zhang, Hanyu
The measurement of volatile organic compounds (VOCs) was conducted during November 2014 in the suburban area of Beijing, China, covering the period of the Asia-Pacific Economic Cooperation (APEC) meeting period. The VOCs characteristics and source apportionment were analyzed. The average mass concentrations of VOCs were 27.6 ± 19.7 μg/m3 during the sampling period, and aromatics and alkanes were the most abundant VOCs species in atmospheric environment in Beijing which were 12.2 ± 10.3 μg/m3 and 11.3 ± 7.5 μg/m3, respectively. The hourly variation of VOCs was found, with the highest concentration occurring at 8:00 to 9:30 and lowest at 12:30 to 14:00. The sampling period was divided into two periods: period Ⅰ represent the period without emission-reduction measures, and period Ⅱ represent the period with reduction measures. The VOCs concentrations during the period Ⅱ was 31.0% lower than period Ⅰ. The Maximum Incremental Reactivity (MIR) method was applied to analysis the ozone formation potential (OFP). The OFP of VOCs from period Ⅰ was 1.6 times higher than period Ⅱ, and the majority of VOCs species were alkenes and aromatics. Positive matrix factorization was applied to estimate contributions of potential VOCs sources. The vehicle exhaust emission was the major source of VOCs during the two periods, and the contribution to VOCs was 5.7% lower during period Ⅱ than period Ⅰ due to the emission-reduction of vehicle operation.
Afficher plus [+] Moins [-]Microplastics in personal care products: Exploring perceptions of environmentalists, beauticians and students Texte intégral
2016
Anderson, A.G. | Grose, J. | Pahl, S. | Thompson, R.C. | Wyles, K.J.
Microplastics enter the environment as a result of larger plastic items breaking down (‘secondary’) and from particles originally manufactured at that size (‘primary’). Personal care products are an important contributor of secondary microplastics (typically referred to as ‘microbeads’), for example in toothpaste, facial scrubs and soaps. Consumers play an important role in influencing the demand for these products and therefore any associated environmental consequences. Hence we need to understand public perceptions in order to help reduce emissions of microplastics. This study explored awareness of plastic microbeads in personal care products in three groups: environmental activists, trainee beauticians and university students in South West England. Focus groups were run, where participants were shown the quantity of microbeads found in individual high-street personal care products. Qualitative analysis showed that while the environmentalists were originally aware of the issue, it lacked visibility and immediacy for the beauticians and students. Yet when shown the amount of plastic in a range of familiar everyday personal care products, all participants expressed considerable surprise and concern at the quantities and potential impact. Regardless of any perceived level of harm in the environment, the consensus was that their use was unnatural and unnecessary. This research could inform future communications with the public and industry as well as policy initiatives to phase out the use of microbeads.
Afficher plus [+] Moins [-]Natural mitigation factor adjustment for re-suspended particulate matter emissions inventory for Bogotá, Colombia Texte intégral
2016
Pérez, María Paula | Henderson, Barron H. | Nedbor-Gross, Robert | Pachón, Jorge E.
This work improves atmospheric emissions of particulate matter in Bogotá Colombia, and provides a tool applying this technique around the world. Bogotá's air pollution is largely impacted by particulate matter, and specifically by re-suspended particulate matter (RPM). RPM sources include paved and unpaved roads, agricultural tilling, construction activities, mining and quarrying. RPM emissions are frequently estimated using annual emission factors, time-varying vehicle traffic activity, a time/space invariant meteorological scaling factor, and a time/space invariant correction factor. This work updates the meteorological factors to be hour-specific, and replacing the correction factor with land use-specific local deposition factors. These techniques are codified in a flexible Python tool based on EPA's AP42 methods and the broader emission literature.Meteorology inhibits RPM emission directly via precipitation scavenging and indirectly by accumulation of road surface moisture. The effects of precipitation and surface moisture are parameterized as mitigation factors differently for paved and unpaved roads due to their porosity and drainage characteristics.These estimates of hourly mitigation factors (on average for paved roads: 0.86 and for unpaved roads: 0.61) agree well with annual factors previously used (paved: 0.90; unpaved: 0.60), however hourly factors have clear diurnal patterns that reduce emissions more significantly latter in the day for paved roads (00–12: 0.95; 12–24: 0.78), and to a lesser extent for unpaved roads (00–12: 0.64; 12–24: 0.58).Emissions are also significantly reduced by vehicle induced turbulence and local deposition. The transportable fraction (0.59 ± 0.22), parameterized based on land use, significantly reduced emissions and correlates with unpaved roads (r = 0.30) more so than with paved roads (r = 0.02). These fractions were used to construct a new inventory, which might improve air pollution predictions compared to the raw inventory, as well as new efforts to simulate exposure fields in Bogotá and our understanding of local particulate sources and sinks.
Afficher plus [+] Moins [-]Research on carbon emissions embodied in trade between China and South Korea Texte intégral
2016
Yang, Yu | Fei-fan, Chen
With the signature of the free trade agreement, trade ties will develop rapidly between China and South Korea. Based on input–output model, this paper calculates and decomposes the embodied carbon emissions in the trade between China and South Korea from 2000 to 2010, analyses the reasons and gives some future advices. This paper suggests that the embodied carbon emissions surplus is not caused by trade surplus. It further points out that textile and leather industries, chemical manufacturing industries and metal manufacturing industries are three main sectors contributing to imported and exported embodied carbon emissions. In addition, the trade diversion between China and South Korea helps a lot in reducing the global carbon emissions and eases the pressure of carbon emissions in China. This paper also proposes that China should learn advanced technologies from South Korea and reduce carbon-intensive energy consumption in the future.
Afficher plus [+] Moins [-]The invasive lionfish, Pterois volitans, used as a sentinel species to assess the organochlorine pollution by chlordecone in Guadeloupe (Lesser Antilles) Texte intégral
2016
Charlotte, Dromard R. | Yolande, Bouchon-Navaro | Cordonnier, Sebastien | Claude, Bouchon
In Guadeloupe, many marine organisms are affected by an organochlorine pollution used in the past by the banana industry to fight against the banana weevil. In the present study, we evaluated the level of contamination of the invasive Indo-Pacific lionfish, Pterois volitans, all around the island. Concentrations of chlordecone varied from 3 to 144μg.kg−1 wet weight. The highest concentrations were recorded when samples were captured in the marine zones located downstream of the previous banana plantations. This contamination seemed to decrease rapidly with the distance from the coast. Mean concentration of chlordecone in Pterois volitans was higher than that of five other fish species collected in similar sites. Due to its position at the top of the trophic web, lionfish was affected by bioaccumulation of chlordecone and can be used as a sentinel species to assess and control the level of contamination of the marine environment by chlordecone.
Afficher plus [+] Moins [-]Lead, cadmium and mercury in the blood of the blue-footed booby (Sula nebouxii) from the coast of Sinaloa, Gulf of California, Mexico Texte intégral
2016
Lerma, Miriam | Castillo-Guerrero, José Alfredo | Ruelas-Inzunza, Jorge | Fernández, Guillermo
We used blood samples of the Blue-footed Booby, considering sex (female and male) and age-class (adult and chick) of individuals at different breeding stages during two breeding seasons (2010–2011 and 2011–2012) in Isla El Rancho, Sinaloa, to determine lead, cadmium, and mercury concentrations. Lead and cadmium concentrations were below our detection limit (0.05 and 0.36ppm, respectively). A higher concentration of mercury was found in early stages of breeding, likely related to changes in mercury environmental availability. Mercury concentrations in adults did not relate with their breeding output. Males and adults had higher mercury concentration than females and chicks. We provide information of temporal, sex and age-related variations in the concentrations of mercury in blood of the Blue-footed Booby.
Afficher plus [+] Moins [-]Biases and best approaches for assessing debris ingestion in sea turtles, with a case study in the Mediterranean Texte intégral
2016
Casale, Paolo | Freggi, Daniela | Paduano, Valentina | Oliverio, Marco
In a sample of 567 loggerhead turtles (Caretta caretta) from the central Mediterranean, debris occurrence varied according to methods and turtle source, and was up to 80% in pelagic turtles. Frequencies of plastic types, size and color are also reported. These results and a critical review of 49 studies worldwide indicate that: (i) the detected occurrence of plastic (% turtles) is affected by several factors (e.g., necropsy/feces, ecological zone, type and date of finding, captivity period for feces collection), (ii) mixed dataset and opportunistic approaches provide results which are biased , not comparable, and ultimately of questionable value, (iii) only turtles assumed to have had a normal feeding behaviour at the time of capture or death should be considered, (iv) turtle foraging ecology and possible selectivity may undermine the use of turtles as indicator species for monitoring marine litter, as recently proposed for the Mediterranean.
Afficher plus [+] Moins [-]The phenomena of spreading ambient ozone at the west coast air basin of Taiwan Texte intégral
2016
Liang, Chen-Jui | Xue, Yang-Shen | Liang, Jeng-Jong
The total air pollution model (TAPM, www.cmar.csiro.au/research/tapm) was used to explore the phenomena of spreading ambient ozone in the complex 196 km × 196 km terrain of the west coast air basin of Taiwan (including ocean area). The altitude in the air basin ranges from 0 m (sea level) to 3000+ m (high mountain). The data of 2010–2014 from 21 air-quality monitoring stations were used to ensure the accuracy of the simulation results in accordance with an average index of agreement (IOA) > 0.61. Four ozone-spreading phenomena were observed among the air basin: the north–south spreading on the offshore (N–S SOO), north–south spreading around the coast (N–S SAC), east–west spreading from the ocean (E–W SFO), and east–west spreading around the mountain front (E–W SAMF). The results indicate that when two prevailing flows meet and interact at their boundaries, they form a convergence zone. The convergence zone presents distinctive weather conditions and accumulates air pollutants. More than wind direction, the ozone concentration is dependent on the topography and surrounding conditions. The results clearly show that the ozone-spreading phenomena follow certain rules. The N–S SOO, N–S SAC, E–W SFO, and E–W SAMF phenomena are during the northeaster, fore-southwester, southwester, and fore-northeaster monsoon months, respectively. Wind fields are a major factor in the high concentration of ozone and ozone spreading, especially downdraft and onshore winds. The diversion of river valleys and the mountainous barrier between the basin/hill and mountains exert obvious influences on the local wind field, strongly affecting the ozone-spreading phenomena.
Afficher plus [+] Moins [-]Metal contamination and its ecological risk assessment in the surface sediments of Anzali wetland, Caspian Sea Texte intégral
2016
Jamshidi, Siamak | Bastami, Kazem Darvish
In this study, the accumulation of metals, including Al, Fe, Zn, V, Ni, Cu, Cr, Cd, Co, As, and Pb, in sediments of Anzali wetland in the southwest region of the Caspian Sea was investigated. For this purpose, the sediments were collected from 17 sampling sites in Anzali wetland, Caspian Sea. The samples were then analyzed using inductively coupled plasma–optical emission spectrometry (ICP-OES). Pearson correlation coefficient showed significant and positive correlation between concentration of all metals (except As and Cd). Furthermore, the results implied that Al and Fe are probably responsible for the transportation of heavy metals into the sediments of Anzali wetland. According to mean effects range-median quotient (mean ERM quotient), the sediments from Anzali wetland had a 21% probability of toxicity.
Afficher plus [+] Moins [-]Impact of sea-land breezes on 210Pb in southern Iberian Peninsula – Feasibility study on using submicron-sized aerosol particles to analyze 210Pb hourly patterns Texte intégral
2016
Hernández-Ceballos, M.A. | Sorribas, M. | San Miguel, E.G. | Cinelli Calvoli, Giovanni | Adame, J.A. | Bolívar, J.P.
This work addresses the impact of mesoscale circulations on 210Pb concentrations in southwestern Iberian Peninsula by analysing the 210Pb database at El Arenosillo station during 2004–2011 (128 periods with a time scale of 48 h).The analysis of surface winds during each one of these periods has revealed the positive impact of the two sea-land breeze patterns (pure and non-pure), previously identified in this region, on 210Pb activity concentrations. An average value of 0.80 ± 0.09 mBq m−3 was obtained for the pure pattern (34 periods), 0.54 ± 0.09 mBq m−3 for the non-pure pattern (23 periods) and 0.46 ± 0.04 mBq m−3 for the rest (71 periods).The analysis of one representative period of each sea-land breeze patterns is also presented. To perform this analysis we have used: hourly surface wind observations, surface wind fields simulated by the WRF mesoscale model and the hourly database of sub-micron-particle size range in the accumulation mode (NACC). The use of this type of particles to investigate the hourly temporal variability of 210Pb is based on the high correlation, obtained in the present work, between 210Pb activity and particles in the accumulation mode (R = 0.90).The analysis reveals that the highest concentrations of NACC, and hence, 210Pb, are obtained when the sampling area is under the influence of the pure breeze, due to it favours the accumulation of particles previously transported by Mediterranean flows along the Guadalquivir valley. In the case of the non-pure pattern, the increase in the concentration of particles is related to the arrival of background synoptic winds from the continental areas of western Iberian Peninsula. In the latest, the increment of NACC is faster and around 400 particles cm−3, while in the case of the pure pattern, it is progressive up to 1400 particles cm−3.
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