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41.
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Naszradi T Badacsonyi A Keresztényi I Podar D Csintalan Z Tuba Z 《Environmental monitoring and assessment》2007,134(1-3):279-285
Moss transplants of Tortula ruralis were used as active biomonitoring organisms as part of a monitoring study to assess the metals (Al, Cd, Cu, Cr, Fe, Ni, Pb, V and Zn) associated with ambient particles on mosses in Budapest, the capital town of Hungary. The moss samples were collected in a nature conservation area from a semi-arid sand grassland (Festucetum vaginatae danubiale), less than 1 month before transplantation. Moss cushions were exposed to pollution in Budapest during October–November 1993 and February–March 1994. In the study area, 16 sites were marked out as measuring sites, in accordance with the structure of the city. A similar stand was established in the Botanical Gardens of the Szent István University in Gödöll? as a control site. ICP-AES analysis of moss for metals showed the ability of Tortula ruralis to accumulate the metals under study. Control site showed lower impact in comparison to the other sites. 相似文献
43.
An air quality sampling program was designed and implemented to collect the baseline concentrations of respirable suspended
particulates (RSP = PM10), non-respirable suspended particulates (NRSP) and fine suspended particulates (FSP = PM2.5). Over a three-week period, a 24-h average concentrations were calculated from the samples collected at an industrial site
in Southern Delhi and compared to datasets collected in Satna by Envirotech Limited, Okhla, Delhi in order to establish the
characteristic difference in emission patterns. PM2.5, PM10, and total suspended particulates (TSP) concentrations at Satna were 20.5 ± 6.0, 102.1 ± 41.1, and 387.6 ± 222.4 μg m−3 and at Delhi were 126.7 ± 28.6, 268.6 ± 39.1, and 687.7 ± 117.4 μg m−3. Values at Delhi were well above the standard limit for 24-h PM2.5 United States National Ambient Air Quality Standards (USNAAQS; 65 μg m−3), while values at Satna were under the standard limit. Results were compared with various worldwide studies. These comparisons
suggest an immediate need for the promulgation of new PM2.5 standards. The position of PM10 in Delhi is drastic and needs an immediate attention. PM10 levels at Delhi were also well above the standard limit for 24-h PM10 National Ambient Air Quality Standards (NAAQS; 150 μg m−3), while levels at Satna remained under the standard limit. PM2.5/PM10 values were also calculated to determine PM2.5 contribution. At Satna, PM2.5 contribution to PM10 was only 20% compared to 47% in Delhi. TSP values at Delhi were well above, while TSP values at Satna were under, the standard
limit for 24-h TSP NAAQS (500 μg m−3). At Satna, the PM10 contribution to TSP was only 26% compared to 39% in Delhi. The correlation between PM10, PM2.5, and TSP were also calculated in order to gain an insight to their sources. Both in Satna and in Delhi, none of the sources
was dominant a varied pattern of emissions was obtained, showing the presence of heterogeneous emission density and that nonrespirable
suspended particulate (NRSP) formed the greatest part of the particulate load. 相似文献
44.
The size of particles in urban air varies over four orders of magnitude (from 0.001 μm to 10 μm in diameter). In many cities
only particle mass concentrations (PM10, i.e. particles <10 μm diameter) is measured. In this paper we analyze how differences
in emissions, background concentrations and meteorology affect the temporal and spatial distribution of PM10 and total particle
number concentrations (PNC) based on measurements and dispersion modeling in Stockholm, Sweden. PNC at densely trafficked
kerbside locations are dominated by ultrafine particles (<0.1 μm diameter) due to vehicle exhaust emissions as verified by
high correlation with NOx. But PNC contribute only marginally to PM10, due to the small size of exhaust particles. Instead
wear of the road surface is an important factor for the highest PM10 concentrations observed. In Stockholm, road wear increases
drastically due to the use of studded tires and traction sand on streets during winter; up to 90% of the locally emitted PM10
may be due to road abrasion. PM10 emissions and concentrations, but not PNC, at kerbside are controlled by road moisture.
Annual mean urban background PM10 levels are relatively uniformly distributed over the city, due to the importance of long
range transport. For PNC local sources often dominate the concentrations resulting in large temporal and spatial gradients
in the concentrations. Despite these differences in the origin of PM10 and PNC, the spatial gradients of annual mean concentrations
due to local sources are of equal magnitude due to the common source, namely traffic. Thus, people in different areas experiencing
a factor of 2 different annual PM10 exposure due to local sources will also experience a factor of 2 different exposure in
terms of PNC. This implies that health impact studies based solely on spatial differences in annual exposure to PM10 may not
separate differences in health effects due to ultrafine and coarse particles. On the other hand, health effect assessments
based on time series exposure analysis of PM10 and PNC, should be able to observe differences in health effects of ultrafine
particles versus coarse particles. 相似文献
45.
采用设置在上海市中心城区交通主干道旁空气质量自动监测站2018年1—12月的观测数据,分析黑碳气溶胶(BC)污染特征及其与PM_(2.5)、SO_2、NO_x、CO、O_3、苯、甲苯、乙苯、二甲苯和气象参数的相关性。结果表明,观测期间内,BC小时均值为(3 038±22) ng/m~3,ρ(BC)在ρ(PM_(2. 5))中占比为(11. 48±0. 12)%。日内ρ(BC)变化呈双峰型,各月份之间ρ(BC)变化不大。ρ(BC)与风速呈负相关,与PM_(2. 5)、NO_x、CO、苯、甲苯、乙苯和二甲苯呈正相关。 相似文献
46.
Bison and cattle grazing management,bare ground coverage,and links to suspended sediment concentrations in grassland streams 下载免费PDF全文
Bartosz P. Grudzinski Melinda D. Daniels Kyle Anibas David Spencer 《Journal of the American Water Resources Association》2016,52(1):16-30
This study quantified the impact of bison and cattle grazing management practices on bare ground coverage at the watershed, riparian, and forested riparian scales within the Flint Hills ecoregion in Kansas. We tested for correlations between bare ground coverage and fluvial suspended sediment concentrations during base‐flow and storm‐flow events. We used remotely sensed imagery combined with field surveys to classify ground cover and quantify the presence of bare ground. Base‐flow water samples were collected bi‐monthly during rain‐free periods and 24 h following precipitation events. Storm‐flow water samples were collected on the rising limb of the hydrograph, using single‐stage automatic samplers. Ungrazed treatments contained the lowest coverage of bare ground at the watershed, riparian, and forested riparian scales. Bison treatments contained the highest coverage of bare ground at the watershed scale, while high‐density cattle treatments contained the highest coverage of bare ground at the riparian and forested riparian scales. In bison and cattle‐grazed treatments, a majority of bare ground was located near fence lines, watershed boundaries, and third‐ and fourth‐order stream segments. Inorganic sediment concentrations at base flow were best predicted by riparian bare ground coverage, while storm‐flow sediment concentrations were best predicted by watershed scale bare ground coverage. 相似文献
47.
综合运用变异系数、泰尔指数及ESDA-GIS多种方法,在充分考虑传统经济影响因子的基础上,尝试引入经济发展生态成本指标,分析长江中游城市群经济综合发展水平与生态成本的空间匹配及演化模式。研究表明:经济综合发展水平高低聚集特征明显,空间极化现象是导致区域经济发展不平衡的主要原因;生态成本空间集聚现象以高高集聚和低低集聚为主,且呈现出高高集聚减少、低低集聚增多的现象,生态成本消耗有所改善;2001~2012年长江中游城市群市域经济综合发展水平与生态成本表现出越来越显著的差异化空间格局,呈现出由低经济综合发展水平-低生态成本过渡到高经济综合发展水平-高生态成本,进而发展到高经济综合发展水平-低生态成本的空间匹配模式的阶段性特征;高经济综合发展水平-高生态成本的经济发展模式仍在大部分城市中存在,经济与生态空间协调发展的潜力仍然很大。 相似文献
48.
能源短缺和环境污染已成为中国推行全面协调可持续发展的重要制约因素,作为能源消耗的主体和环境污染的控制重点,在城市层面推动能源发展战略的转变和强化环境保护是发展的基本要求.鉴于能源与环境之间的高度关联性,在管理方面要求对能源发展和环境保护进行统筹考虑和综合管理,充分强调能源经济效率和环境制约因素在能源发展中的作用.通过制定合理的产业能效标准和排放绩效标准,为城市经济、能源和环境的可持续性发展提供科学性、系统性决策支持. 相似文献
49.
50.
通过对大连城市环境系统的考察,设立了完整的评价指标体系,运用模糊优选理论建立模糊评价模型,对大连城市环境进行了定量研究,并结合经济和城市化情况进行了分析。研究结果表明:城市环境质量总体上是在逐年提高的,但从2002年以来发展较为平缓。经济和城市化情况有较大发展,但仍有不足之处。 相似文献