title: PM2.5 in Beijing - temporal pattern and its association with influenza.
abstract: BACKGROUND
  Air pollution in Beijing, especially PM2.5, has received increasing attention in the past years. Despite Beijing being one of the most polluted cities in the world, there has still been a lack of quantitative research regarding the health impact of PM2.5 on the impact of diseases in Beijing. In this study, we aimed to characterize temporal pattern of PM2.5 and its potential association with human influenza in Beijing.
  
  
  METHODS
  Based on the data collected on hourly ambient PM2.5 from year 2008 to 2013 and on monthly human influenza cases from 2008 and 2011, we investigated temporal patterns of PM2.5 over the five-year period and utilized the wavelet approach to exploring the potential association between PM2.5 and influenza.
  
  
  RESULTS
  Our results found that ambient PM2.5 pollution was severe in Beijing with PM2.5 concentrations being significantly higher than the standards of the World Health Organization, the US EPA, and the Chinese EPA in the majority of days during the study period. Furthermore, PM2.5 concentrations in the winter heating seasons were higher than those in non-heating seasons despite high variations. We also found significant association between ambient PM2.5 peak and human influenza case increase with a delayed effect (e.g. delayed effect of PM2.5 on influenza).
  
  
  CONCLUSIONS
  Ambient PM2.5 concentrations were significantly associated with human influenza cases in Beijing, which have important implications for public health and environmental actions.
authors.forename: Yijia
authors.initials: Y
authors.lastname: Liang
authors.forename: Liqun
authors.initials: L
authors.lastname: Fang
authors.forename: Hui
authors.initials: H
authors.lastname: Pan
authors.forename: Kezhong
authors.initials: K
authors.lastname: Zhang
authors.forename: Haidong
authors.initials: H
authors.lastname: Kan
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Brook
authors.affiliation: Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 424 Cunz Hall, 1841 Neil Avenue, Columbus, OH 43210, USA. sun.224@osu.edu.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Sun
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002681:China / Q000453:epidemiology; D002947:Cities / Q000453:epidemiology; D004784:Environmental Monitoring; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter