title: Worldwide associations between air quality and health end-points: are they meaningful?
abstract: OBJECTIVE
  The World Health Organization (WHO) provides data on national indices of health, environment and economy. When we were asked, why air pollution is negatively correlated with cancer mortality, our first response (presumably the mortality data are not age-adjusted) was not sufficient to explain the paradox.
  
  
  METHODS
  A table including all-cause, cancer and childhood mortality, life expectancy, gross national product per person, smoking prevalence, physician density and particulate matter (PM10) per country (N = 193) was developed. For explorative purposes weighted cross-sectional multiple linear regressions models were built.
  
  
  RESULTS
  Air pollution is positively correlated with infant and overall mortality and negatively with life expectancy. This might not only depict a true causal effect of PM10 because air quality is also an indicator of a country's prosperity and general state of environment. Cancer mortality is negatively correlated with PM10. However, this association turns positive when economic or health system indicators are controlled.
  
  
  CONCLUSIONS
  The World Health Organization's world-wide data sets demonstrate the large disparity of our world. A careful and professional approach is needed as interpretation is difficult, especially for lay persons. Therefore, with publicly available data WHO should also provide interpretation and guidance.
authors.affiliation: Institute of Environmental Health, Medical University Vienna, Vienna, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Wallner
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Hutter
authors.forename: Hanns
authors.initials: H
authors.lastname: Moshammer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis*; D002648:Child; D046688:Child Mortality / Q000639:trends; D002675:Child, Preschool; D004781:Environmental Exposure / Q000032:analysis; D004784:Environmental Monitoring; D005260:Female; D014943:Global Health; D006801:Humans; D007223:Infant; D007226:Infant Mortality / Q000639:trends; D007231:Infant, Newborn; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000401:mortality*; D052638:Particulate Matter / Q000032:analysis; D010820:Physicians / Q000600:supply & distribution; D015995:Prevalence; D012907:Smoking / Q000453:epidemiology; D014944:World Health Organization
chemical_list: D052638:Particulate Matter