Comparisons of urban and rural PM10−2.5 and PM2.5 mass concentrations and semi-volatile fractions in northeastern Colorado
Item
Title (Dublin Core)
Comparisons of urban and rural PM10−2.5 and PM2.5 mass concentrations and semi-volatile fractions in northeastern Colorado
Description (Dublin Core)
Coarse (PM<sub>10−2.5</sub>) and fine (PM<sub>2.5</sub>) particulate matter in the atmosphere adversely affect human health and influence climate. While PM<sub>2.5</sub> is relatively well studied, less is known about the sources and fate of PM<sub>10−2.5</sub>. The Colorado Coarse Rural-Urban Sources and Health (CCRUSH) study measured PM<sub>10−2.5</sub> and PM<sub>2.5</sub> mass concentrations, as well as the fraction of semi-volatile material (SVM) in each size regime (SVM<sub>2.5</sub>, SVM<sub>10−2.5</sub>), from 2009 to early 2012 in Denver and comparatively rural Greeley, Colorado. Agricultural operations east of Greeley appear to have contributed to the peak PM<sub>10−2.5</sub> concentrations there, but concentrations were generally lower in Greeley than in Denver. Traffic-influenced sites in Denver had PM<sub>10−2.5</sub> concentrations that averaged from 14.6 to 19.7 µg m<sup>−3</sup> and mean PM<sub>10−2.5</sub> ∕ PM<sub>10</sub> ratios of 0.56 to 0.70, higher than at residential sites in Denver or Greeley. PM<sub>10−2.5</sub> concentrations were more temporally variable than PM<sub>2.5</sub> concentrations. Concentrations of the two pollutants were not correlated. Spatial correlations of daily averaged PM<sub>10−2.5</sub> concentrations ranged from 0.59 to 0.62 for pairs of sites in Denver and from 0.47 to 0.70 between Denver and Greeley. Compared to PM<sub>10−2.5</sub>, concentrations of PM<sub>2.5</sub> were more correlated across sites within Denver and less correlated between Denver and Greeley. PM<sub>10−2.5</sub> concentrations were highest during the summer and early fall, while PM<sub>2.5</sub> and SVM<sub>2.5</sub> concentrations peaked in winter during periodic multi-day inversions. SVM<sub>10−2.5</sub> concentrations were low at all sites. Diurnal peaks in PM<sub>10−2.5</sub> and PM<sub>2.5</sub> concentrations corresponded to morning and afternoon peaks of traffic activity, and were enhanced by boundary layer dynamics. SVM<sub>2.5</sub> concentrations peaked around noon on both weekdays and weekends. PM<sub>10−2.5</sub> concentrations at sites located near highways generally increased with wind speeds above about 3 m s<sup>−1</sup>. Little wind speed dependence was observed for the residential sites in Denver and Greeley. The mass concentration data reported here are being used in ongoing epidemiologic studies for PM in northeastern Colorado.
Creator (Dublin Core)
Clements, Nicholas
Hannigan, Michael P.
Miller, Shelly L.
Peel, Jennifer L.
Milford, Jana B.
Date (Dublin Core)
2018-09-09
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-16-7469-2016
https://acp.copernicus.org/articles/16/7469/2016/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
