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Your search keyword '"Hu, Xuefei"' showing total 4 results
Start Over Author "Hu, Xuefei" Journal environmental health perspectives
4 results on '"Hu, Xuefei"'

1. Satellite-Based Spatiotemporal Trends in PM2.5 Concentrations: China 2004-2013

Author

Ma, Zongwei, Hu, Xuefei, Sayer, Andrew M, Levy, Robert, Zhang, Qiang, Xue, Yingang, Tong, Shilu, Bi, Jun, Huang, Lei, and Liu, Yang

Subjects
Earth Resources And Remote Sensing
Abstract

Three decades of rapid economic development is causing severe and widespread PM2.5(particulate matter (is) less than 2.5 ) pollution in China. However, research on the health impacts of PM2.5 exposure has been hindered by limited historical PM2.5 concentration data. We estimated ambient PM2.5 concentrations from 2004 to 2013 in China at 0.1 deg resolution using the most recent satellite data and evaluated model performance with available ground observations. We developed a two-stage spatial statistical model using the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 aerosol optical depth (AOD) and assimilated meteorology, land use data, and PM2.5 concentrations from China's recently established ground monitoring network. An inverse variance weighting (IVW) approach was developed to combine MODIS Dark Target and Deep Blue AOD to optimize data coverage. We evaluated model predicted PM2.5 concentrations from 2004 to early 2014 using ground observations. The overall model cross-validation R(sup 2) and relative prediction error were 0.79 and 35.6%, respectively. Validation beyond the model year (2013) indicated that it accurately predicted PM(sub 2.5) concentrations with little bias at the monthly (R(sup 2) = 0.73), regression slope = 0.91) and seasonal (R(sup 2) = 0.79), regression slope = 0.92) levels. Seasonal variations revealed that winter was the most polluted season and that summer was the cleanest season. Analysis of predicted PM2.5 levels showed a mean annual increase of 1.97 micro-g/cu cm between 2004 and 2007 and a decrease of 0.46 micro-g/cu cm between 2008 and 2013. Our satellite-driven model can provide reliable historical PM2.5 estimates in China at a resolution comparable to those used in epidemiologic studies on the health effects of long-term PM2.5 exposure in North America. This data source can potentially advance research on PM2.5 health effects in China.

Published
2016
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2. Pediatric emergency visits and short-term changes in [P.M.sub.2.5] concentrations in the U.S. State of Georgia

Author

Strickland, Matthew J., Hao, Hua, Hu, Xuefei, Chang, Howard H., Darrow, Lyndsey A., and Liu, Yang

Subjects
Air quality -- Evaluation, Air pollution -- Research -- Health aspects, Particles -- Research -- Influence, Environmental issues, Health
Abstract

Background: Associations between pediatric emergency department (ED) visits and ambient concentrations of particulate matter [less than or equal to] 2.5 µm in diameter ([PM.sub.2.5]) have been reported in previous studies, although few were performed in nonmetropolitan areas. OBJECTIVE: We estimated associations between daily [PM.sub.2.5] concentrations, using a two-stage model that included land use parameters and satellite aerosol optical depth measurements at 1-km resolution, and ED visits for six pediatric conditions in the U.S. state of Georgia by urbanicity classification. METHODS: We obtained pediatric ED visits geocoded to residential ZIP codes for visits with nonmissing [PM.sub.2.5] estimates and admission dates during 1 January 2002-30 June 2010 for 2- to 18-year-olds for asthma or wheeze (n = 189,816), and for 0- to 18-year-olds for bronchitis (n = 76,243), chronic sinusitis (n = 15,745), otitis media (n = 237,833), pneumonia (n = 52,946), and upper respiratory infections (n = 414,556). Daily ZIP code-level estimates of 24-hr average [PM.sub.2.5] were calculated by averaging concentrations within ZIP code boundaries. We used time-stratified case-crossover models stratified on ZIP code, year, and month to estimate odds ratios (ORs) between ED visits and same-day and previous-day [PM.sub.2.5] concentrations at the ZIP code level, and we investigated effect modification by county-level urbanicity. RESULTS: A 10-µg/[m.sup.3] increase in same-day [PM.sub.2.5] concentrations was associated with ED visits for asthma or wheeze (OR = 1.013; 95% CI: 1.003, 1.023) and upper respiratory infections (OR = 1.015; 95% CI: 1.008, 1.022); associations with previous-day [PM.sub.2.5] concentrations were lower. Differences in the association estimates across levels of urbanicity were not statistically significant. CONCLUSION: Pediatric ED visits for asthma or wheeze and for upper respiratory infections were associated with [PM.sub.2.5] concentrations in Georgia. http://dx.doi.org/10.1289/ehp.1509856., Introduction Efforts to model ambient air quality have progressed rapidly in recent years. One area that has been advanced is the estimation of particulate matter ≤ 2.5 µm in diameter [...]

Published
2016
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