23 resultados para Air pollution
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
IEECAS SKLLQG
Elemental carbon in urban soils and road dusts in Xi'an, China and its implication for air pollution
Resumo:
Total air suspended particles (PM 100) collected from an urban location near a traffic line in Wuhan, China, were examined for estrogen using a recombinant yeast bioassay. Wuhan, located at the central part of China, is the fourth biggest city in China with 7 million populations. Today, Wuhan has developed into the biggest city and the largest traveling center of central China, becoming one of the important bases of industry, education and research. Wuhan is right at the confluent point of Yangzi River, the third longest river in the world, and its largest distributary Hanjiang, with mountains and more than 100 takes in downtown area. Therefore, by its unique landscape, Wuhan has formed clear four seasons with relatively long winter and summer and short spring and autumn. Foggy weather usually happen in early spring. The yeast line used in this assay stably expresses human estrogen receptor-alpha. Weak but clear estrogenic activities were detected in the organic phase of crude extracts of air particle materials (APM) in both sunny and foggy weather by 0.19-0.79 mug E2/gPM(100) which were statistically significantly elevated relative to the blank control responding from 20% to 50% of the maximum E2 response, and the estrogenic activity was much higher in foggy weather than in sunny weather. The estrogenic activities in the sub-fractions from chromatographic separation of APM sampled in foggy days were also determined. The results indicated that the responses of the fractions were obviously higher than the crude extracts. Since there is no other large pollution source nearby, the estrogenic material was most likely from vehicle emissions, house heating sources and oil fumes of house cooking. The GC/MS analysis of the PM100 collected under foggy weather showed that there were many phenol derivatives, oxy-PAHs and resin acids which have been reported as environmental estrogens. These results of the analysis of estrogenic potency in sunny and foggy weather in a subtropical city of China indicate that further studies are required to investigate the actual risks for the associated health and atmospheric system. (C) 2004 Elsevier Ltd. All rights reserved.
Resumo:
本文研究了木本植物的不同部位即叶片、枝条和树皮以及植物的生理指标如气孔阻力对大气S02、TSP和重金属污染的指示和监测作用,并用树木年轮指示大气污染的历史和程度。结果认为: 承德市大气污染自1703年城市化以来开始出现,但达到严重污染水平则出现在本世纪50年代以来尤其是最近10-20年城市化与工业化的加剧,主要污染物以S02为主,从避暑山庄修建前的<0.1μg m-3达到目前的30μg m-3,重金属污染Fe自1927-45大庙铁矿开采后出现,Mn、Ni、Pb等出现在工业化以来的最近40-50年中,上述污染物含量在木质部年轮中明显升高,如S增加了10倍以上,Pb增加了560% (P<0.00l)。 不同城市功能区树皮pH和气孔阻力不同,主要与大气中的S02和TSP有关,据此可监测大气S02和TSP污染。前者以榆树、加拿大杨、垂柳和国槐最佳,相关系数分别可达-0.8384 (P<0.0l),-0.7447、-0.6904和-0.6552 (P<0.05);后者则以白腊和旱柳下表皮最好,相关系数达0.9968和0.9951 (P<0.00l)。在扫描电镜下发现气孔受大气TSP影响出现不同程度的堵塞现象,主要有2种途径,小型颗粒物(<5μm)进入气孔腔,大型颗粒物(>30μm)可将气孔封盖。 植物不同器官部位污染物含量以树皮为最高,其次是枝条或叶,因而适宜的指示或监测部位是叶或枝条。主分量分析认为:承德市大气污染物以S为主,重金属Fe、Zn、Mn也有一定的贡献,Pb仅出现在繁忙道路区。不同季节污染物含量变化以休眠期最高,生长初期次之,生长旺盛期最低,如S和Pb分别从0.75 mg g-1和0.7 mg g-1上升到1.5 mg g-1和2.0 mg g-1(P<0.001)。植物不同季节污染物含量的变化反应了大气污染物季节变化特点,因而可以指示或监测大气污染尤其是S02污染。其中刺槐多部位复相关模型监测效果最佳,复相关系数可达0.987;某些植物单一部位的监测作用也较好,叶以珍珠梅最佳,相关系数为0.8695 (P<0.001),枝以油松、珍珠梅、垂柳为好(r≥0.8,P <0.001),树皮以刺槐为佳,r=0.8615 (P<0.0l)。植物不同部位的污染物含量还可用来评价大气环境质量,其中复合污染指数可以 评价总的大气环境质量,S污染指数和重金属污染指数可以评价S02、重金属和TSP污染,与直接利用污染物浓度法基本一致。油松不同部位对于大气S02的指示作用可表现为年轮对大气污染历史的指示或监测,针叶对现状S02污染的预测,并利用针叶对于S02的监测结果,绘制了大气S02污染分布图。 总之,本文利用古松年轮和现状城市植物的枝条、叶和树皮中的污染物含量以及树皮酸度等不同方面的指标,对承德市大气污染的历史和现状进行了指示与监测,即承德市大气污染从过去到现在均以S02为主,植物不同部位可以非常有效地进行大气S02污染的监测与评价,其中多部位的复相关模型预测效果极佳。另外,由植物监测而绘制的大气S02分布图,较准确地揭示了承德市大气S02现状分布规律。
Resumo:
Exposure to indoor air pollution (IAP) from the combustion of biomass fuels is an important cause of morbidity and mortality in developing countries. In the work discussed in this paper we evaluated the endocrine activity of soot particles from biomass fuels by using yeast bioassay. These pollutants could have beta-galactosidase activity with a relative potency (RP) about 10(-7)-10(-9) that of estradiol. Soot particles from wood and straw combustion only partially induced beta-galactosidase activity whereas others produced fully inductive activity in the yeast assay system. These pollutants did not have estrogen antagonist and progesterone agonist activity within the defined concentration range. However, these pollutants require 2-4 orders of magnitude higher IC50 to inhibit the activity of progesterone in a similar dose-response manner to mifepristone. We therefore propose that the endocrine activity of some environmental pollutants may be because of inhibition of the progesterone receptor (hPR). GC-MS results showed that substituted polycyclic aromatic hydrocarbon (PAH) compounds, substituted phenolic compounds and derivatives, aromatic carbonyl compounds, and phytosteroids in these soot particles may be mimicking endogenous hormones.