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941.
部分城市空气中颗粒物的元素组成比较 总被引:7,自引:0,他引:7
通过对数浓度图和分歧系数对中国广义、武汉、兰州和重庆4座城市空气中粗细颗粒物的42种元素组成进行了比较。结果表明,与人类活动有关的污染元素主要富集在细颗粒物中,而粗颗粒物中元素相对于细颗粒物来说更多的来自于土壤;同一座城市内城区同郊区相比,元素污染更严重,城郊之间细颗粒物中元素在短距离和有利地形下传输作用十分明显。同时还比较了城市之间的元素污染程度。结果表明,兰州城区相对于其它采校点位颗粒物中元素污染较为 相似文献
942.
943.
沈阳市大气细菌与真菌粒子的关系 总被引:3,自引:1,他引:3
用ANDERSEN生物粒子采样器对沈阳市大气细菌和真菌粒子的密度、密度分布、粒度分布及两者关系进行了观察和。结果表明,沈阳市大气年平均密度细菌粒子为7228个/m^3,真菌粒子为1797个/m^3,细菌为真菌的4.1倍。细菌粒子密度和粒度均呈正偏态分布,真菌粒子密度和粒度均呈对数正态分布。〈8.2μm的可吸入粒子,细菌为4326个/m^3,占其总数的61.4%;真菌为1583个/m^3,占其总数的 相似文献
944.
四川中东部地区2009年大气硫沉降模拟 总被引:1,自引:1,他引:1
采用第三代公共多尺度空气质量模型Models-3/CMAQ,对四川中东部地区2009年1月、4月、7月和10月SO2排放所产生的硫沉降分布进行数值模拟研究,并且将该模型输出的ρ(SO2)、SO42-湿沉降量分别与地面层的ρ(SO2)、降水中SO42-湿沉降量实测值进行相关分析,探讨硫沉降的季节、区域分布特征及湿沉降变化. 结果表明:ρ(SO2)模拟值与实测值的R(相关系数)为0.445,SO42-湿沉降量模拟值与实测值的R为0.510;四川中东部地区夏季硫沉降量为2.2×104 t,高于其他三季,冬季最小,为1.0×104 t;硫沉降呈三大片区分布,宜宾、乐山、泸州为高值分布区,资阳、遂宁、南充、广安和达州均属于硫沉降低值区,成都、德阳、绵阳片区属硫沉降次高值区;干沉降中SO2沉降量在各季所占比例均在85%以上,湿沉降中各季SO42-沉降量所占比例均在99%以上. 相似文献
945.
为了研究区域输送对河南省PM2.5重污染的影响,利用中国科学院大气物理研究所自主研发的NAQPMS(嵌套网格空气质量预报)模式模拟了河南省2014年1月12─19日的一次污染事件. 污染期间,河南省所有城市ρ(PM2.5)小时均值最大值均超过250 μg/m3,达到了严重污染水平. 利用基于NAQPMS的污染源来源追踪方法评估了本地排放和区域输送的影响. 结果表明:研究期间,本地排放和区域输送对河南省ρ(PM2.5)的平均贡献率分别达到了50.6%和49.4%. 在区域输送方面,安徽省对河南省ρ(PM2.5)的贡献率(10.0%)最高,山西省(9.2%)、陕西省(8.5%)次之,河北省(仅2.1%)最低. 分地区来看,河南省中部地区以本省累积(贡献率为61.4%,下同)为主,东部地区以安徽省(30.4%)输送为主,南部地区以本省累积(45.1%)、湖北省(14.1%)及安徽省 (13.7%)输送为主,西部地区以陕西省(35.4%)输送为主,北部地区则主要以本省累积(58.1%)及山西省(20.7%)输送为主. 研究表明,尽管河南省各地区同时出现高污染,但其来源不同,有必要采取区域联防联控措施. 相似文献
946.
南京市环境监测中心站在全国率先开展空气质量周报,之后又开展了空气质量日报,向市民公布空气质量状况,使环境监测成果走向社会,服务于百姓,增强了全社会的环境保护意识,提高了市民关心环境,保护环境的自觉性,并推动了空气污染防治工作,促进了环境监测工作,体现了 相似文献
947.
张泓 《环境监测管理与技术》1999,11(6):34-36
空气中氧化硫的测定对实验室测定条件比较敏感。通过实验表明显色时间,显色温度,盐酸副玫瑰苯胺纯度,蒸馏水质量等试验条件均对其校准曲线有影响,故在分析过程中,必须严格把握操作条件,遵循操作步骤。 相似文献
948.
Yannopoulos PC 《Environmental science and pollution research international》2007,14(3):172-175
Background The development of the city of Patras, including harbour relocation, in conjunction with the protection of the regional ecosystems,
requires air quality assessment and management. For this reason, a model applicable in the Patras area is necessary and valuable.
The goal of this study was to validate a model suitable for predicting the dispersion of sulfur dioxide (SO2), based on particular activity, topography and weather conditions.
Methods We used the US-EPA ISCLT3 integral dispersion model to predict SO2 concentrations for Patras, Greece. We assumed that the major contribution to Patras air pollution came from central heating,
harbour and traffic. We calculated traffic emissions using COPERTIII.
Results and Discussion Assigning suitable values of the mixing height, the model predicted the local and spatial distribution of the mean monthly
SO2 concentrations in downtown Patras, as well computed the contribution of the SO2 emissions originating from each particular source at each receptor location on a seasonal and annual basis. The comparison
between predictions and measurements shows that the model performance for estimating the SO2 concentrations and period pattern is satisfactory.
Conclusion The mixing height was the critical parameter for calibrating the model. Model validation promises satisfactory predictions
for SO2 pollution levels on monthly basis.
Recommendations and Outlook The model could be used in predicting SO2 concentrations and source contribution for several downtown Patras receptors using pertinent meteorological and emission
information. It could be also extended to predict the dispersion of other primary air pollutants. The calibrated model predictions
could be used to fill gaps in monitoring data, saving money and time, and help in assess and manage air quality as Patras
develops. 相似文献
949.
Smith LA Stock TH Chung KC Mukerjee S Liao XL Stallings C Afshar M 《Environmental monitoring and assessment》2007,128(1-3):369-379
In the summer of 2003, ambient air concentrations of volatile organic compounds (VOCs) were measured at 12 sites within a
3-km radius in Deer Park, Texas near Houston. The purpose of the study was to assess local spatial influence of traffic and
other urban sources and was part of a larger investigation of VOC spatial and temporal heterogeneity influences in selected
areas of Houston. Seventy 2-h samples were collected using passive organic vapor monitors. Most measurements of 13 VOC species
were greater than the method detection limits. Samplers were located at 10 residential sites, a regulatory air monitoring
station, and a site located at the centroid of the census tract in which the regulatory station was located. For residential
sites, sampler placement locations (e. g., covered porch vs. house eaves) had no effect on concentration with the exception
of methyl tertiary-butyl ether (MTBE). Relatively high correlations (Pearson r > 0.8) were found between toluene, ethylbenzene, and o,m,p-xylenes suggesting petroleum-related influence. Chloroform was not correlated with these species or benzene (Pearson r < 0.35) suggesting a different source influence, possibly from process-related activities. As shown in other spatial studies,
wind direction relative to source location had an effect on VOC concentrations. 相似文献
950.
Delhi is an instructive location for studying the impact of air pollution since it is a rapidly expanding centre of government,
trade commerce and industry. We have made an attempt to (1) determine the association between environmental pollution and
respiratory morbidity in Delhi for the period 1998–2004, (2) assess the impact on hospital admission of the implementation
of recent governmental regulations and (3) calculate the relative risk of hospitalization due to respiratory ailments caused
by air pollutants. Seven hospitals from different parts of Delhi were selected. The pollution profiles of these areas were
assessed and subsequently Poisson regression model was performed for the patient population. There was a remarkable decrease
in monthly average concentration of sulphur dioxide (from 17.9 to 11.1 μg m−3) and increase in monthly average concentration of nitrogen dioxide (from 34.2 to 49.1 μg m−3) after the newly introduced regulations. Particulates were observed to have marginal fall in their concentration but still
remained above the permissible limits. Gaseous pollutants, in spite of being at a level lower than the permissible level,
showed more consistent significant association with respiratory admissions. The relative risks of hospitalization due to respiratory
diseases were in the range of 1.07–2.82 in residential cum commercial areas. Comparative study of pre and post new stringent
governmental regulation showed significant positive association of NO2 with respiratory disorders in southern (RR: 1.10; CI: 1.09–1.12) and northern regions (RR: 1.33; CI: 1.27–1.39), both mixed
use areas. In spite of the improvement in the air quality, the associated health effects were found to be substantial. 相似文献