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1.
Nitrogen oxides emissions in Asia during the period 1990–2020 due to anthropogenic activity are presented. These estimates are based on the RAINS-ASIA methodology (Foell et al., 1995, Acid Rain and Emission Reduction in Asia, World Bank), which includes a dynamic model for energy forecasts, and information on 6 energy sectors and 9 fuel types. The energy forecasts are combined with process emission factors to yield NOx emission estimates at the country level, the regional level, and on a 1 degree by 1 degree grid. In 1990 the total NOx emissions are estimated to be ∼19 Tg NO2, with China (43%), India (18%) and Japan (13%) accounting for 75% of the total. Emissions by fuel are dominated by burning of hard coal and emissions by economic activity are dominated by the power, transport, and industrial sectors. These new estimates of NOx emissions are compared with those published by Hameed and Dignon (1988, Atmospheric Environment 22, 441–449) and Akimoto and Narita (1994, Atmospheric Environment 28, 213–225). Future emissions under a no-further-control scenario are also presented. During the period 1990–2020 the NOx emissions increase by 350%, to ∼86 Tg NO2. The increase in NOx emissions by sector and end-use varies between countries, but in all countries this increase is strongest in the power and transport sectors. These results highlight the dynamic nature of energy use in Asia, and the need to take the rapid growth in NOx emissions in Asia into account in studies of air pollution and atmospheric chemistry.  相似文献   

2.
Selected organonitrogen, organophosphorus and organochlorine pesticides have been determined in precipitation samples collected at 10 sites in the Gdańsk region (northern Poland) over a period of one year (1998). Compounds which were detected most often included simazine (0.11-5.80 ng/l), fenitrothion (0.1-2.10 ng/l), chlorfenvinfos (0.1-1.30 ng/l), gamma-HCH (0.012-5.06 ng/l), heptachlor epoxide (0.05-3.28 ng/l) and aldrin (0.02-3.28 ng/l). The pesticide concentrations in precipitation samples revealed seasonal fluctuations, with higher concentrations observed during the application periods (June and July). The concentrations observed were also affected by the inflow of polluted air masses from the southwest. The total pesticide concentration in the precipitation samples was strongly related to the abundance of green areas in the vicinity of the sampling sites. A weak correlation was also found between the total concentration of organonitrogen and organophosphorus pesticides, and the total concentration of organochlorine pesticides in the samples collected.  相似文献   

3.
Environmental Science and Pollution Research - Sandy cropland ecosystems are major terrestrial ecosystems in semi-arid regions of northern China’s Horqin Sandy Land, where they play an...  相似文献   

4.
Jiang S  Liu X  Chen Q 《Chemosphere》2011,83(8):1108-1116
The toxicities and bioavailabilities of total mercury (THg) and methylmercury (MeHg) in aquatic systems have made them the subjects of recent research. In this study, we collected a lake sediment core from Ny-Ålesund in Svalbard and analyzed the distributions of THg and MeHg in the sediments. The increased trend of THg was caused by anthropogenic contamination since the 14th century through long-range transportation, especially after the industrial era. However, the peak values of Hg in surface sediment samples could be explained by the increased algal scavenging process in recent decades. All the biogeochemical proxies (e.g., pigments and diatom biomass) revealed recent sharp increases in aquatic primary production due to the current climate warming. Rock-Eval analyses indicated that algal-derived organic matter took up a large portion, and quantitative calculation showed that 89.6-95.8% of the Hg in post-1950 could be explained by scavenging. The distribution of MeHg has a close relationship with total Hg and organic matter. The oxidation-reduction condition is one of the possible factors affecting the methylation rates in H2 lake sediments. Higher algal productivity and organic matter actually led to the increased trend of methylation in the uppermost sediment. This study supports some new key hypotheses on climate-driven factors affecting Hg and MeHg cycling in High Arctic lake sediments.  相似文献   

5.
This study focused on establishing trends in the period 1988–2001 in PM2.5, PM10 and ozone concentrations in Santiago, Chile, and linking those to population exposure. There is strong seasonality in the concentration levels, driven by prevailing meteorological conditions, with the concentration of particulates peaking at the beginning of winter, whereas the ozone concentration is highest during the summer. The levels of PM2.5 and PM10 have substantially decreased since the late 1980s and so has the population exposure. Nevertheless, the majority of the population is still exposed to annual average levels that are above standard values. The situation with ozone exposure is different; no substantial decrease can be observed in the data. If anything, certain parts of Santiago, notably the south-east, have shown increased levels of ozone. Overall population exposure indicates that the average person was more at risk of ozone in the year 2000 than they were in 1993.  相似文献   

6.
Environmental Science and Pollution Research - The fact is that output volatility and carbon dioxide (CO2) emissions move together over the period. This empirical study examines the dynamic effect...  相似文献   

7.

Introduction  

The concentration of a pharmaceutical found in the environment is determined by the amount used by the patient, the excretion and metabolism pattern, and eventually by its persistence. Biological degradation or persistence of a pharmaceutical is experimentally tested rather late in the development of a pharmaceutical, often shortly before submission of the dossier to regulatory authorities.  相似文献   

8.
Residues of pesticides were surveyed in 132 samples of cow milk collected from bulk transports (38 samples of raw milk) and market (94 samples of pasteurised milk). These samples were analysed by the multiresidue analytical method DFG S19 for pesticide contamination. More than 70 active substances were studied and the identification and quantification were made by gas chromatographic technique. The results showed that 0.76% of samples were contaminated with HCH (alpha isomer) and 10.60% with endosulfan (alpha and beta isomers). Both pesticides, endosulfan and HCH, found in milk samples, indicated their use in agriculture practices, although legislation in Brazil does not permit the use of HCH since 1985 and endosulfan can be used only in a few crops. These compounds should not be present in milk because there are implications on human health. Organophosphorus, carbamates, pyrethroids, herbicides, and fungicides were not detected in cow's milk samples.  相似文献   

9.
Annual and seasonal trends were discussed for precipitation chemistry in Japan on the basis of a nationwide monitoring network by Japan Environment Agency. For this analysis, 17 sites, selected from the 23 network sites after evaluation of data completeness for the present purpose, were grouped into four areas in terms of the sea which could characterize each area: the Pacific Ocean, the Japan Sea, the Seto Inland Sea and the East China Sea areas. Major ion concentrations at each site were subjected to least-squares multiple regression analysis, and discussion was principally focused on the area-groups. Each area showed significant (p<0.05) decreasing trends in non-sea-salt sulfate (nss-SO42−) concentrations with the annual mean change rate of −3.0% yr−1, whereas no significant trends were detected for NO3 at 59% of the sites. Ammonium (NH4+) showed significant increasing trends for 35%, and decreasing trends for 18% of the sites; and, the maximum change rate of 3.8% yr−1 was recorded in the Pacific Ocean area. Non-sea-salt calcium (nss-Ca2+) concentrations significantly decreased in northern and some industrialized areas. Both the annual cycle-amplitudes and effects of precipitation amounts were significant for the four ions at almost all sites. The maximum concentrations of nss-SO42− and -Ca2+ occurred from winter to spring at most sites. The seasons when the maximum concentrations of NO3 and NH4+ occurred, were found to differ from area to area. Furthermore, the trends in precipitation nss-SO42−, and NO3 were qualitatively consistent with those of anthropogenic emissions of SO2, and NOx in Japan, respectively.  相似文献   

10.
Ozone concentrations were measured at two (urban and a rural) sites near the city of Málaga (Spain). The aim of this study was to determine the daily, monthly and seasonal variation patterns of ozone concentrations at both sites and to study the possible regional influences. The daily variations mostly have the usual features with the afternoon maximum and the night minimum being more pronounced in the urban area. The average monthly concentrations throughout the year start to increase in March reaching their maximum values in July for the urban site. However, in the rural area, the monthly variations are smaller reaching their maximum value in June. The hourly evolution of the ozone concentrations in both sampling sites is well defined in spring and summer and not so well defined in autumn and winter. Taking into account the four seasons, the rural concentrations are higher than the urban ones. Summer is the season when there are similar concentrations at both sampling sites. Average hourly summer afternoon ozone for the hours 12:00-20:00 LST exceeded the 110 microg m(-3) European Union guidelines for human health for 8 h ozone exposure at the urban and rural sites.  相似文献   

11.
The study of mercury (Hg) cycle in Arctic regions is a major subject of concern due to the dramatic increases of Hg concentrations in ecosystem in the last few decades. The causes of such increases are still in debate, and an important way to improve our knowledge on the subject is to study the exchanges of Hg between atmosphere and snow during springtime. We organized an international study from 10 April to 10 May 2003 in Ny-Ålesund, Svalbard, in order to assess these fluxes through measurements and derived calculations.Snow-to-air emission fluxes of Hg were measured using the flux chamber technique between ∼0 and 50 ng m−2 h−1. A peak in Gaseous Elemental Mercury (GEM) emission flux from the snow to the atmosphere has been measured just few hours after an Atmospheric Mercury Depletion Event (AMDE) recorded on 22 April 2004. Surprisingly, this peak in GEM emitted after this AMDE did not correspond to any increase in Hg concentration in snow surface. A peak in GEM flux after an AMDE was observed only for this single event but not for the four other AMDEs recorded during this spring period.In the snow pack which is seasonal and about 40 cm depth above permafrost, Hg is involved in both production and incorporation processes. The incorporation was evaluated to ∼5–40 pg m2 h. Outside of AMDE periods, Hg flux from the snow surface to the atmosphere was the consequence of GEM production in the air of snow and was about ∼15–50 ng m−2 h−1, with a contribution of deeper snow layers evaluated to ∼0.3–6.5 ng m−2 h−1. The major part of GEM production is then mainly a surface phenomenon. The internal production of GEM was largely increasing when snow temperatures were close to melting, indicating a chemical process occurring in the quasi-liquid layer at the surface of snow grains.  相似文献   

12.
Emission reductions were mandated in the Clean Air Act Amendments of 1990 with the expectation that they would result in major reductions in the concentrations of atmospherically transported pollutants. This paper investigates the form and magnitude of trends from 1989 to 1995 in atmospheric concentrations of sulfur dioxide, sulfate, and nitrogen at 34 rural sites in the eastern US. Across all sites, there is strong evidence of statistically significant declining trends in sulfur dioxide (median change of -35%) and sulfate concentrations (median change of -26%). In general, trends in nitrogen concentrations were not as pronounced (median change of -8%) as trends in the sulfur compounds. A regional estimate of trend for a cluster of sites in the Ohio River valley showed close correspondence between declining sulfur dioxide concentrations (-35%) and changes in sulfur dioxide emissions (-32%) in this region.  相似文献   

13.
Pina JM  Moraes RM 《Chemosphere》2007,66(7):1310-1314
Psidium guajava 'Paluma' was evaluated under field conditions as a tropical bioindicator species of ozone (O(3)). Three exposures of 90 days each were performed (June 21, 2004-March 19, 2005). In each one of them, saplings of 'Paluma' (n=30) were exposed to ambient air at a site in S?o Paulo (Brazil) with high ozone concentrations, and in a greenhouse with charcoal-filtered air. Ozone-like visible foliar injuries were observed during the winter, spring and summer exposures, when AOT40 reached 6166ppbh, 3504ppbh and 4828ppbh, respectively. No injuries were observed in the plants kept under filtered air. The injuries consisted in red stippling on adaxial leaf surfaces. They did not cover the veins and appeared first in older leaves, becoming more intense as the exposure period increased. Injury incidence, severity, and the cumulative exposure threshold at injury onset varied among the exposure periods. AOT40 explained partly the incidence, severity and leaf injury index LII (r(2)=0.52, 0.39, 0.38, respectively, p=0.002). The results confirm the potential of the species as an O(3)-sensitive bioindicator.  相似文献   

14.

Background

Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited.

Methods

The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender?Cage matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2??-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed.

Results

Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 ??g/l; well water: 14.20 vs. 0.79 ??g/l, pond water: 135.68 vs. 0.37 ??g/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p?p?p?Conclusions The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers.  相似文献   

15.
16.
Sustainable development has become a key aspect in society, economics and environment. Therefore, experts dealing with questions relating to people, the environment and its resources are more and more requested. This paper presents the concept and first experiences of a specialised Master's Degree in Sustainable Development (MSD). This is a pioneer course as it is equally anchored in three faculties (Human science, Natural science, Business and Economy) at the University of Basel, Switzerland. It aims to transmit knowledge, teach methodology and enable practical work experience in the field of sustainable development. This interdisciplinary master's degree is composed of several modules. At first, the attendance of modules providing a basic understanding in the disciplines not yet covered by the former Bachelor degree, is mandatory. In optional modules, the acquired knowledge of the compulsory modules is further enhanced, focussing on four different topics and are titled as: Agglomeration and Ecosystems; Conservation and Utilisation of Natural Resources; Environment, Values, Societal Transformation and Health; and Environmental Problems in a Globalised World. In another optional module, students may complete an internship in which they can apply theoretical and thematic knowledge. To work independently on a problem in the context of, interdisciplinary projects are a central request in the MSD. Finally, the master thesis has to be planned and realized by a plying the scientific methods and skills acquired in the previous modules. Since the beginning of the programme in the winter of 2005/2006, 45 students have enrolled. They received degrees at 25 different universities, 13 of which are from abroad. Some already have several years of working experience, while others have only just completed their Bachelor's degrees. A analysis has shown that the graduates will have excellent chances in the employment market, since they are well qualified to take over sought-after positions in the business world, in administration, in consultancy, national or international organisations, or to follow academic careers.  相似文献   

17.
Sodium metabisulfite is used in marine shrimp harvesting to prevent the occurrence of black spots. Shrimps are soaked in a sodium metabisulfite solution in ice, which is disposed of in sewages that run into marine canals, creating an environmental hazard. This study evaluates the toxicity and mutagenicity caused by sodium metabisulfite in sea waters and sediments collected in a shrimp farm in Cajueiro da Praia (Luis Correia), state of Piauí, Brazil, using the Allium cepa assay. Water and sediment samples were collected in the dry and in the rainy seasons, in three sites: upstream the shrimp farm (Site 1), at the point sodium metabisulfite is discharged (Site 2), and 100 m downstream the farm (Site 3). Three sample dilutions were used (50%, 25% and 10%) for all samples. A negative control (well water) and a positive control (copper sulfate 0.0006 mg mL−1) were used in each experiment. At the end of the 72-h exposure period, onion roots were measured and removed. Mutagenicity analysis included the determination of mitotic index, chromosomal aberrations and the detection of micronuclei; analysis of root size and mitotic index were used as an index of toxicity. The A. cepa assay revealed that the water and sediments samples collected in the Piauí coast contaminated with sodium metabisulfite induce toxicity. The results demonstrate that the assay may be used as a regular tool in the analysis of water parameters in shrimp farms in the coast of Piauí state, and in strategies to preserve the region’s marine ecosystem.  相似文献   

18.
Chongqing, a city with a population of >2.5 million, constitutes the biggest industrial and commercial centre in southwest China. Recent industrialization has led to an increasing air pollutant problem which is exacerbated by the topography and prevailing climate of the region. To date, interest has remained firmly focused on the levels of traditional air pollutants (sulphur dioxide [SO2], oxides of nitrogen [NOx], smoke and suspended particulate matter [SPM]), with little attention paid to photochemical oxidants such as ozone (O3). This paper reports the first assessment of ambient O3 levels in southwest China. Measurements were made in and around Chongqing using a combination of UV-absorption (at a site located in the northern sector of the city) and passive samplers (at 20 sites located in and around the city) between 1993 and 1996. The 7-h daily mean O3 concentrations ranged between 2 and 16 ppb (x10(9)) during the winter months, increasing to 18-41 ppb during the summer (June-August), when peak hourly mean O3 concentrations of 93 ppb were attained. Ozone exposures across the region commonly approached (or exceeded) UN-ECE and WHO short-term guidelines for the protection of crops. In addition, controlled chamber studies, in which 11 cultivars of Chinese crops commonly grown in the Chongqing region were screened for relative O3 sensitivity, indicated the potential for subtle effects on the growth of a number of crop plants, if ambient O3 levels continue to rise in the region. Employing ozone exposures somewhat higher than those experienced in the field, several cultivars of commonly grown Chinese cereal, vegetable and salad crops were found to be sensitive to O3 in terms of growth, but this was not always associated with the appearance of visible symptoms of injury and, in contrast to what was generally expected, only three species showed significant O3-induced reductions in root:shoot partitioning. There is a clear and urgent need for a comprehensive study of ambient air quality and its impact on crops and natural vegetation in this, as in other, rapidly developing regions of China.  相似文献   

19.
The constancy, both temporal and spatial, of the profile of polycyclic aromatic hydrocarbons (PAHs) relative to benzo[a]pyrene (BaP) is a prerequisite to using the BaP-indicator approach in the carcinogenic risk assessment for PAHs. The principal aim of this study was to provide a contribution to validate this approach, by studying the variability of the profile at a typical urban site through a multi-year data set and by comparing the profiles available for different cities. Seven carcinogenic PAHs (benz[a]anthracene, benzo[b+j+k]fluoranthenes, BaP, indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene) were determined in PM10 24-h samples collected every third day at a road site; moreover, benzo[e]pyrene was determined as a reference PAH due to its stability. The profile was found stable from year to year. Besides, it was similar to those recently found in other European cities (observed differences within a factor of four) and to those elaborated from earlier (1970s–1980s) investigations. The substantial similarity of profiles, both temporal (on an annual basis) and spatial, supports the validity of the BaP-indicator approach. Large PAH-to-PAH differences were, however, found in the seasonal pattern of profile: they were explained by the different atmospheric degradability of PAHs, whose effect is enhanced under the meteoclimatic conditions typical of the European Mediterranean countries. PAH annual means showed a slight declining trend since 1994. In the last sampling year, mean concentration of BaP was 1.2 ng m−3. Within-year differences among monthly averaged PAH concentrations were observed, as large as up to 44-fold for BaP, underlining the need for whole-year monitoring.  相似文献   

20.
In order to characterize atmospheric aerosol in the São Paulo Metropolitan Area, aerosols were sampled during the winter months of August 1999 and August 2000. A micro-orifice uniform deposit impactor (MOUDI) was used. Samples were submitted to gravimetry, as well as to proton-induced X-ray emission (PIXE), carbon (black and organic) and ion-chromatography analysis. These analyses supplied information about mass concentrations and physicochemical properties of the particles. Due to the higher humidity, which can increase soluble particles diameters, and reduced atmospheric stagnation seen in 2000, average PM10 concentrations were higher (105 μg m−3) in the winter of 1999 than in the winter of 2000 (60 μg m−3). The PIXE analysis revealed metals and metal compounds, soil-derived elements, Si-rich particles, sulfates, carbonates, chlorides and other anthropogenic air-borne particles, supposing molecules in their usual composition. Mass balance for PM2.5 revealed significant participation of organic and black carbon, probably resulting from diesel burning by the heavy-duty fleet.  相似文献   

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