DOI: 10.1016/j.atmosenv.2018.02.042
Scopus记录号: 2-s2.0-85043979194
论文题名: Evaluation of missing value methods for predicting ambient BTEX concentrations in two neighbouring cities in Southwestern Ontario Canada
作者: Miller L ; , Xu X ; , Wheeler A ; , Zhang T ; , Hamadani M ; , Ejaz U
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2018
卷: 181 起始页码: 126
结束页码: 134
语种: 英语
英文关键词: Air quality
; Benzene
; BTEX
; Imputation
; Inter-specie ratios
; Missing values
; VOCs
Scopus关键词: Air quality
; Autocorrelation
; Benzene
; Inverse problems
; Toluene
; Volatile organic compounds
; Benzene , toluene , ethylbenzene , and xylenes
; BTEX
; Imputation
; Inter-specie ratios
; Inverse distance weighting
; Missing values
; Pollutant concentration
; Spatial concentration
; Quality control
; air quality
; benzene
; BTEX
; concentration (composition)
; environmental assessment
; industrial emission
; numerical method
; pollution monitoring
; prediction
; urban pollution
; volatile organic compound
; Canada
; Ontario [Canada]
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: High density air monitoring campaigns provide spatial patterns of pollutant concentrations which are integral in exposure assessment. Such analysis can assist with the determination of links between air quality and health outcomes, however, problems due to missing data can threaten to compromise these studies. This research evaluates four methods; mean value imputation, inverse distance weighting (IDW), inter-species ratios, and regression, to address missing spatial concentration data ranging from one missing data point up to 50% missing data. BTEX (benzene, toluene, ethylbenzene, and xylenes) concentrations were measured in Windsor and Sarnia, Ontario in the fall of 2005. Concentrations and inter-species ratios were generally similar between the two cities. Benzene (B) was observed to be higher in Sarnia, whereas toluene (T) and the T/B ratios were higher in Windsor. Using these urban, industrialized cities as case studies, this research demonstrates that using inter-species ratios or regression of the data for which there is complete information, along with one measured concentration (i.e. benzene) to predict for missing concentrations (i.e. TEX) results in good agreement between predicted and measured values. In both cities, the general trend remains that best agreement is observed for the leave-one-out scenario, followed by 10% and 25% missing, and the least agreement for the 50% missing cases. In the absence of any known concentrations IDW can provide reasonable agreement between observed and estimated concentrations for the BTEX species, and was superior over mean value imputation which was not able to preserve the spatial trend. The proposed methods can be used to fill in missing data, while preserving the general characteristics and rank order of the data which are sufficient for epidemiologic studies. © 2018 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/82908
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: Department of Civil and Environmental Engineering, University of Windsor, Ontario, Windsor, Canada; Air Health Science Division, Health Canada, Ontario, Ottawa, Canada; Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
Recommended Citation:
Miller L,, Xu X,, Wheeler A,et al. Evaluation of missing value methods for predicting ambient BTEX concentrations in two neighbouring cities in Southwestern Ontario Canada[J]. Atmospheric Environment,2018-01-01,181