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991.
Yoo Jung Kim Jung-Hun Woo Young-Il Ma Suhyang Kim Jung Sik Nam Hakyoung Sung Ki-Chul Choi Jihyun Seo Jeong Su Kim Chang-Hee Kang Gangwoong Lee Chul-Un Ro Duk Chang Young Sunwoo 《Atmospheric environment (Oxford, England : 1994)》2009,43(34):5556-5566
In this study, background concentration sites of Deokjeok and Gosan, which were deemed suitable for monitoring the impact of long-range transported air pollutants, were selected. An investigation of the source types of pollutants, their locations, and relative quantitative contributions to the particulate concentrations at both sites using appropriate methodologies to make initial estimations was conducted. Episodic measurements of PM2.5, PM10, and size distribution, along with its ion and carbon components were performed from 2005 to 2007, and a comprehensive analysis of the results was conducted utilizing back trajectory analysis. As for frequency of wind direction, it was quite apparent that the two sites are heavily influenced by air masses originating from the eastern and northern regions of China. For PM2.5 and PM10, the mass concentrations from north and east China were higher than other cases, originating from the ocean. In the northerly-wind case, meteorological properties for Deokjeok and Gosan and the influence of carbon emissions from northwest Korea resulted in a changing of air mass properties during transport. As was the case with mass concentration, the highest contribution for ionic and carbon components of PM2.5 and PM10 for both sites appeared for the westerly wind case. A specially high relative contribution, greater than 1.4 times, was apparent in the secondary aerosol case because of a large influence of long-range transported pollutants from east China. Carbon components exhibited different behaviors for the northerly and westerly wind cases compared with secondary aerosol. The major reason for this discrepancy appears to be the carbon emissions from northwest Korea. 相似文献
992.
This article develops a dynamic model of efficient use of exhaustible marine sand resources in the context of marine mining externalities. The classical Hotelling extraction model is applied to sand mining in Ongjin, Korea and extended to include the estimated marginal external costs that mining imposes on marine fisheries. The socially efficient sand extraction plan is compared with the extraction paths suggested by scientific research. If marginal environmental costs are correctly estimated, the developed efficient extraction plan considering the resource rent may increase the social welfare and reduce the conflicts among the marine sand resource users. The empirical results are interpreted with an emphasis on guidelines for coastal resource management policy. 相似文献
993.
Nguyen Thi Kim Oanh Prapat Pongkiatkul Nabin Upadhyay Phillip P. Hopke 《Atmospheric environment (Oxford, England : 1994)》2009,43(21):3334-3344
Particulate matter (PM) receptor modeling requires specific intensive input data that is always a challenge to produce cost effectively. A well-designed monitoring program is important to collect such PM ambient data in urban areas with diverse and densely distributed sources. This paper presents a general framework for designing such a monitoring program while emphasizing appropriate quality assurance and quality control elements that are particularly applicable where limited resources are available. Topics for discussion include selection of monitoring sites, sampling and analytical techniques, and the uncertainty estimation for ambient concentration input data. The design framework is illustrated by a case study of a monitoring program for PM source apportionment in the Bangkok Metropolitan Region in which 24-h fine and coarse PM samples were collected using two collocated dichotomous samplers. Comparison between black carbon measurements by Smoke Stain reflectometry and Thermal Optical Transmittance method is highlighted. 相似文献
994.
Effects of radiative forcing by black carbon aerosol on spring rainfall decrease over Southeast Asia
The effects of black carbon (BC) aerosol radiative forcing on spring rainfall in Southeast Asia are studied using numerical simulations with the NASA finite-volume General Circulation Model (fvGCM) forced with monthly varying three-dimensional aerosol distributions from the Goddard Ozone Chemistry Aerosol Radiation and Transport model (GOCART).During the boreal spring, March–April–May (MAM), BC from local emissions accumulates over Southeast Asia. The BC aerosol layer, which extends from the surface to higher elevation above planetary boundary layer (PBL), absorbs solar radiation and heats the mid-troposphere through a semi-direct effect over regions of large aerosol optical thickness (AOT) and thereby significantly perturbs large-scale and meridional circulations. Results show that anomalous precipitation patterns and associated large-scale circulations induced by radiative forcing by BC aerosol can explain observed precipitation reductions, especially over Southeast Asia. Therefore, BC aerosol forcing may be one of the important factors affecting the spring rainfall trend over Southeast Asia. 相似文献
995.
The overall survey on indoor radon concentration was conducted at all subway stations in a major city, Daejeon in the central part of Korea. It was quarterly performed from September 2007 to August 2008. The annual arithmetic mean of indoor radon concentration of all the stations was 34.1 ± 14.7 Bq m−3, and the range of values was from 9.4 to 98.2 Bq m−3. The radon concentrations in groundwater (average 31.0 ± 0.8 Bq m−3) were not significantly high in most stations, but the concentration (177.9 ± 2.3 Bq L−1) of one station was over the level of 148 Bq L−1 in drinking water proposed by U.S. EPA. Based on indoor survey results, the approximate average of the annual effective dose by radon inhalation to the employees and passengers were 0.24 mSv y−1, and 0.02 mSv y−1, respectively. Although the effective dose based on the UNSCEAR report was potentially estimated, for more accurate assessment, the additional survey on the influence by indoor radon will be necessary. 相似文献
996.
This article examines challenges to food security in areas especially vulnerable to the effects of climate variability and
change, and the potential contribution of seasonal climate forecasting. Drawing on long-term study of the way environmental
information is developed and circulates, and on recent fieldwork in Western Kenya, the article describes how climate variability
exacerbates food insecurity; the kinds of climate information that are now being developed; and the kinds of technologies,
organizations, and expertise that will be needed if new forms of climate information are to benefit vulnerable populations.
Findings indicate that new forms of expertise need to be developed at all scales, and that linkage among stakeholders and
between organizations functioning at different scales will be a considerable challenge. 相似文献
997.
Jake E. Mowrer Paula Sedlacek Jihyuk Kim Casey Ritz 《Journal of environmental science and health. Part. B》2016,51(2):126-131
A study was conducted to evaluate the effects of dietary nitrocompounds on bird performance, ammonia volatilization, and changes in manure nitrogen (N). A total of 200 one-day-old male chicks (Cobb 500) were used for this study. The chicks were raised in electrically heated battery brooders for 18 days. On day 1, birds were allocated into five treatment groups with four replicated pens: (T1) control, a corn and soybean meal diet (3,100 kcal kg?1 metabolizable energy (ME) and 21% Crude Protein (CP)); (T2) 16.7 mg kg?1 nitroethanol (NEL); (T3) 33.3 mg kg?1 NEL; (T4) 16.7 mg kg?1 nitropropanol (NPL); and (T5) 33.3 mg kg?1 NPL. The body weight gain, feed intake and feed efficiency were measured on days 7, 14 and 18. Volatized ammonia (VA) and other N forms were measured at collection and following 2 weeks of incubation at 30°C. Broiler growth was not adversely affected by the nitrocompounds at concentrations up to 33.3 mg kg?1. The results show that initial manure pH was reduced by adding nitroethanol (NEL) and nitropropanol (NPL) to the diet by 0.2 and 0.5 pH units, respectively. Total VA after 2 weeks was unaffected by dietary treatment. The amounts of uric acid decomposed and ammonia produced were closely balanced in the control sample. However, this balance was significantly different among the manures produced by birds receiving nitrocompound treatments. The inclusion of NEL and NPL resulted in the presence of measurable amounts of Xanthine not found in the control group. This study indicates that supplementation of nitroethanol or nitropropanol into broiler diets up to 33.3 mg kg?1 influences uric acid degradation and ammonia production in broiler manure while maintaining optimal growth performance. 相似文献
998.
999.
Dahye Yoon Siwon Kim Minji Lee Changshin Yoon 《Journal of environmental science and health. Part. B》2016,51(12):824-831
A 1H-nuclear magnetic resonance (NMR) spectroscopy with multivariate analysis was applied to detect the toxicity of antiacetylcholinesterase insecticides, methomyl (methyl (1E)-N-(methylcarbamoyloxy)ethanimidothioate) and methidathion (3-(dimethoxyphosphinothioyl sulfanylmethyl)-5-methoxy-1,3,4-thiadiazol-2-one), using zebrafish (Danio rerio) and Chinese bleak (Aphyocypris chinensis). Generally, methomyl and methidathion have been believed not to highly accumulate in fish tissues. However, these pesticides showed their toxicity by altering patterns of whole-body metabolites in neurotransmitter balance, energy metabolism, oxidative stress, and muscle maintenance in low concentrations. We used Pearson correlation analysis to contextualize the metabolic markers in pesticide treated groups. We observed that the positive correlations of choline with acetate and betaine in untreated control were shifted to null correlations showing acetylcholinesterase specific toxicity. This research demonstrated the applicability and potential of NMR metabolomics in detecting toxic effects of insecticide with a modicum of concentrations in aquatic environment. 相似文献
1000.