Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2009-9-24
pubmed:abstractText
The air quality in Beijing and surrounding area is influenced by local emission and regional transport. To study the characteristics of regional pollution, PM (particulate matter) samples were collected simultaneously at 4 sites including Tsinghua University (TH) and Miyun reservoir (MY) in Beijing, Renqiu (RQ, Hebei Province), and Shangdu (SD, Inner Mongolia) during August, 2007, and temporal/spatial distributions of PM2.5 mass concentrations along with 22 elements in TSP were characterized. PM2.5 mass concentrations were quite different at 4 sites, following the sequence as RQ > TH > MY > SD. The highest concentrations of pollution-derived elements S, Zn, Pb, Cu, As, Sb, Ni, Cd, In, Se were found in RQ, showing the most intensive anthropogenic influence around this region, and their lowest variation indicated that the pollution mostly came from local sources. Controlled by the meteorological factors, highest daily variations of these elements were found at SD with relative lower concentrations. The correlation coefficients of S, Pb, Cd, In, As, Zn concentrations between TH and MY were all higher than 0.70, which implies similar sources for these elements at the 2 sites in Beijing. At the beginning and the end of the Sawtooth pollution episode in Beijing, concentrations of most elements in Miyun were comparable with the lowest concentrations at Shangdu observed during the sampling period, which means Miyun could well represent the regional characteristics of clean air mass from the northwest. Uniform spatial distribution of high sulfate was found (about 10 microg/m3) at the peaks of Sawtooth episode, which implies the important contribution from secondary aerosol during the regional pollution. Variable sources of PM at each site and their regional influence were discussed based on the different characteristics of elemental enrichment factors.
pubmed:language
chi
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0250-3301
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1873-80
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
[Regional PM pollution in Beijing and surrounding area during summertime].
pubmed:affiliation
Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. zhaoq@mails.thu.edu.cn
pubmed:publicationType
Journal Article, English Abstract, Research Support, Non-U.S. Gov't