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Characteristics and source apportionment of VOCs in the suburban area of Beijing, China
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.
显示更多 [+] 显示较少 [-]Assessment of concentration, bioaccumulation and sources of polycyclic aromatic hydrocarbons in zooplankton of Chabahar Bay
2016
Ziyaadini, Morteza | Mehdinia, Ali | Khaleghi, Leila | Nassiri, Mahmoud
The amounts and sources of polycyclic aromatic hydrocarbons (PAHs) and their bioaccumulation factors (BAFs) in the zooplankton community of Chabahar Bay were investigated. The highest amounts of total PAHs (tPAHs) in the water and zooplankton samples were 62.2ngL−1 and 1478.6ngg−1 dry weights, in near the Shahid Beheshti Port and desalination, respectively. The greatest amount of BAF (51,780) was obtained in the entry of Bay, and it was related to the phenanthrene accumulation. Using molecular ratio, the results showed that the major input source of PAH compounds in zooplankton of Chabahar Bay was pyrolytic (fuel) source.
显示更多 [+] 显示较少 [-]Geochemistry and bioavailability of mudflats and mangrove sediments and their effect on bioaccumulation in selected organisms within a tropical (Zuari) estuary, Goa, India
2016
Dias, Heidy Q. | Nayak, G.N.
Metals are non-degradable in the aquatic environment and play a vital role in estuarine biogeochemistry but could also be detrimental to associated biota. A comparative evaluation of the trace metal concentrations (Fe, Mn, Zn, Cu, Ni, and Co) was carried out in the Zuari estuary, Goa during the post-monsoon season of 2013 at six locations, each representing three mangrove and three mudflat regions. In addition, fractionation of trace metals in sediments was performed to provide information on the mobility, distribution, bioavailability and toxicity. Special attention was paid to the marine mollusks viz. bivalves and gastropods that are extensively used as bio-indicators in coastal pollution. Considering the percentage of metals in the sequentially extracted fractions, the order of mobility from most to least bioavailable forms was Mn > Zn > Cu > Ni > Co > Fe. Mn maintained high bioavailability (average around 60%) in Fe–Mn oxide and carbonate bound forms indicating that Mn is readily available for biota uptake. The bioavailability of Fe was on an average of around 6% whereas other metals like Cu, Zn, Ni and Co were around 19% to 34%. When the bioavailable values were compared with standard Screening Quick Reference Table (SQUIRT), Zn showed higher toxicity level and bioavailability in the lower estuary. On the basis of calculated Bio Sediment Accumulation Factors (BSAF's), overall trend in bioaccumulation was in the order of Cu > Zn > Mn > Ni > Co > Fe. Metal Pollution Index (MPI) computed was higher for gastropods than bivalves.
显示更多 [+] 显示较少 [-]Localised and limited impact of a dredging operation on coral cover in the northwestern lagoon of New Caledonia
2016
Adjeroud, Mehdi | Gilbert, Antoine | Facon, Mathilde | Foglia, Marion | Moreton, Benjamin | Heintz, Tom
We report here an interannual survey (2006–2012) of coral cover in the northwestern lagoon of New Caledonia, to assess the impact of an important dredging operation (August 2008–February 2010) associated with the construction of the largest nickel mining site in the Pacific. A BACI (Before-After Control-Impact) analysis failed to detect any significant interaction between period (before, during, and after dredging) and the category of the stations (impact vs. control). Among the 31 stations surveyed, only seven showed decreasing coral cover during the study period, mainly due to a decline in Acroporidae. However, the relationship between the dredging and this decrease was highly plausible only for one station, situated 0.9km from the dredging site. High hydrodynamism in the study area, the abundance of resistant corals and efficient protective measures during the dredging operation might explain these localised and limited impacts.
显示更多 [+] 显示较少 [-]Green Marine: An environmental program to establish sustainability in marine transportation
2016
Walker, Tony R.
European maritime companies have adopted programs to limit operational impacts on the environment. For maritime companies in North America, the Green Marine Environmental Program (GMEP) offers a framework to establish and reduce environmental footprints. Green Marine (GM) participants demonstrate annual improvements of specific environmental performance indicators (e.g., reductions in air pollution emissions) to maintain certification. Participants complete annual self-evaluations with results determining rankings for performance indicators on a 1-to-5 scale. Self-evaluations are independently verified every two years to ensure rigor and individual results are made publicly available annually to achieve transparency. GM benefits the marine industry across North America by encouraging sustainable development initiatives. GM's credibility is reflected through a diverse network of environmental groups and government agencies that endorse and help shape the program. Merits of this relatively new maritime certification (not previously described in the academic literature), are discussed.
显示更多 [+] 显示较少 [-]Occurrence and distribution of synthetic musks and organic UV filters from riverine and coastal sediments in the Pearl River estuary of China
2016
Huang, Weixia | Xie, Zhiyong | Yan, Wen | Mi, Wenying | Xu, Weihai
This study reports the occurrence and distribution of synthetic musks (SMs) and organic UV filters (UVFs) in sediment samples collected in 8 riverine runoffs from the Pearl River and Pearl River estuary (PRE). Here, 6 of the 8 target compounds were detected in all sediments with concentrations ranging from 0.35ngg−1 to 456ngg−1. Higher concentrations of SMs and UVFs were evident in the eastern outlets compared to the western suggesting greater input of these contaminants from the Pearl River Delta (PRD) region. All the compounds showed a decreasing trend toward the seaward side which confirming that riverine runoff was the most important source of SMs and UVFs to the coastal environment. Notably, high levels of SMs and UVFs were detected in two fishing harbors in the PRE area. In comparison to UVFs, the SM compounds exhibited a significant correlation with TOC content in the sediments.
显示更多 [+] 显示较少 [-]Environmental effects of the Deepwater Horizon oil spill: A review
2016
Beyer, Jonny | Trannum, Hilde C. | Bakke, Torgeir | Hodson, Peter V. | Collier, Tracy K.
The Deepwater Horizon oil spill constituted an ecosystem-level injury in the northern Gulf of Mexico. Much oil spread at 1100–1300m depth, contaminating and affecting deepwater habitats. Factors such as oil-biodegradation, ocean currents and response measures (dispersants, burning) reduced coastal oiling. Still, >2100km of shoreline and many coastal habitats were affected. Research demonstrates that oiling caused a wide range of biological effects, although worst-case impact scenarios did not materialize. Biomarkers in individual organisms were more informative about oiling stress than population and community indices. Salt marshes and seabird populations were hard hit, but were also quite resilient to oiling effects. Monitoring demonstrated little contamination of seafood. Certain impacts are still understudied, such as effects on seagrass communities. Concerns of long-term impacts remain for large fish species, deep-sea corals, sea turtles and cetaceans. These species and their habitats should continue to receive attention (monitoring and research) for years to come.
显示更多 [+] 显示较少 [-]Optimisation for assay of fluorescein diacetate hydrolytic activity as a sensitive tool to evaluate impacts of pollutants and nutrients on microbial activity in coastal sediments
2016
Jiang, Shan | Huang, Jing | Lu, Haoliang | Liu, Jingchun | Yan, Chongling
Fluorescein diacetate (FDA) assay has been widely applied in coastal research to quantify microbial activity in sediments. However, the present FDA assay procedures embodied in sediment studies potentially include operational errors since the protocol was established for studies of terrestrial soil. In the present study, we optimised the procedure of FDA assay using sandy and cohesive sediments to improve experiential sensitivity and reproducibility. The optimised method describes quantitative measurement of the fluorescein produced when 1.0g of fresh sediment is incubated with 50mM phosphate buffer solution (pH: 7.3) and glass beads (2g) at 35°C for 1h under a rotation of 50rpm. The covariation coefficient of the optimised method ranged from 1.9% to 3.8% and the method sensitivity ranged from 0.25 to 1.57. The improved protocol provides a more reliable measurement of the FDA hydrolysis rate over a wide range of sediments compared to the original method.
显示更多 [+] 显示较少 [-]Characteristics and sources of PM in seasonal perspective – A case study from one year continuously sampling in Beijing
2016
Shen, Rongrong | Schäfer, Klaus | Schnelle-Kreis, Jürgen | Shao, Longyi | Norra, Stefan | Kramar, Utz | Michalke, Bernhard | Abbaszade, Gülcin | Streibel, Thorsten | Fricker, Mathieu | Chen, Yuan | Zimmermann, Ralf | Emeis, Stefan | Schmid, Hans-Peter
Daily mass concentrations and chemical compositions (elemental carbon, organic carbon, water soluble ions, chemical elements and organic species) of PM were measured continuously in Beijing for one year from June 2010 to June 2011 (365 samples). The seasonal variation of PM mass concentration followed the order of spring 2011 > winter 2010 > summer 2010 > autumn 2010. Organic matter (OM) and secondary inorganic aerosol components (SNA: SO42−, NO3− and NH4+) were the two major fractions of PM during the whole year. Source apportionment by PMF performed on the basis of a full year of data, including both inorganic and organic species, showed that biomass burning, secondary sulfate and nitrate formation, mineral dust, industry, coal combustion and traffic were the main sources of PM in Beijing during 2010–2011. Specifically, comparison among the four seasons shows that the contribution of secondary sulfate and biomass burning, secondary nitrate formation, mineral dust, and coal combustion were the dominating sources of PM in summer, autumn, spring and winter, respectively. The contributions of industry to PM was distributed evenly in four seasons, while traffic contributed more in summer and autumn than in winter and spring. Backward trajectory analysis was applied in combination with PMF and showed that air flow from the South contributed mostly to high PM mass concentrations in Beijing. Meteorological parameters (temperature, wind speed, wind direction, precipitation and mixing layer height) influence such a variation. In general, high relative humidity and low mixing layer height can raise PM mass concentration, while high wind speed and precipitation can reduce pollutants. In addition, wind direction also plays a key role in influencing PM because different wind directions can bring different pollutants to Beijing from different regions.
显示更多 [+] 显示较少 [-]Determination of ambient air concentrations and personal exposure risk levels of outdoor workers to carbonyl compounds and BTEX in the inner city of Bangkok, Thailand
2016
Kanjanasiranont, Navaporn | Prueksasit, Tassanee | Morknoy, Daisy | Tunsaringkarn, Tanasorn | Sematong, Saowanee | Siriwong, Wattasit | Zapaung, Kalaya | Rungsiyothin, Anusorn
The ambient and personal air concentrations of benzene, toluene, ethylbenzene and xylenes (BTEX) and carbonyl compounds (CCs) were investigated in Pathumwan district, Bangkok (Thailand), a congested area with a high level of traffic-related air pollution. The potential health risk of three representative groups of street workers (street vendors, motorcycle taxi driver and security guards) exposed to these substances was estimated. The personal air exposure and ambient air samples were collected in the rainy (September 2012) and summer (March 2013) seasons. The 8-h average formaldehyde and acetaldehyde exposure levels for both personal and ambient air concentrations were found to be the major CCs. The highest mean ambient air level of formaldehyde (20.1 μg/m3) was found at the roadside at a busy intersection next to department stores. The highest level of acetaldehyde (9.17 μg/m3) was found in a location with a high traffic load close to the hospital and university. For BTEX, the greatest average concentration was observed around the site located near a bus stop (45.5 μg/m3). In terms of the personal exposure concentrations of CCs and BTEX, no statistically significant differences were found among all sampled locations for street vendors and motorcycle taxi drivers. With respect to the health risk assessment, at a 95% confidence interval (CI) of cancer risk, benzene posed the highest risk followed by formaldehyde and then acetaldehyde (5.36E-06–1.48E-05, 5.58E-06–1.91E-05 and 1.03E-05–5.93E-05 for street vendors, motorcycle taxi driver and security guards) while the 95% CI non-cancer risk values were at an acceptable level. Nevertheless, there were no significant differences in the total cancer risk among the different groups of workers. From the health risk assessment, benzene and formaldehyde were the major traffic related air pollutants that likely affected the human health in this area.
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