title: Does air pollution trigger infant mortality in Western Europe? A case-crossover study.
abstract: BACKGROUND
  Numerous studies show associations between fine particulate air pollutants [particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀)] and mortality in adults.
  
  
  OBJECTIVE
  We investigated short-term effects of elevated PM₁₀ levels on infant mortality in Flanders, Belgium, and studied whether the European Union (EU) limit value protects infants from the air pollution trigger.
  
  
  METHODS
  In a case-crossover analysis, we estimated the risk of dying from nontraumatic causes before 1 year of age in relation to outdoor PM₁₀ concentrations on the day of death. We matched control days on temperature to exclude confounding by variations in daily temperature.
  
  
  RESULTS
  During the study period (1998-2006), PM₁₀ concentration averaged 31.9 ± 13.8 μg/m³. In the entire study population (n = 2,382), the risk of death increased by 4% [95% confidence interval (CI), 0-8%; p = 0.045] for a 10-μg/m³ increase in daily mean PM₁₀. However, this association was significant only for late neonates (2-4 weeks of age; n = 372), in whom the risk of death increased by 11% (95% CI, 1-22%; p = 0.028) per 10-μg/m³ increase in PM₁₀. In this age class, infants were 1.74 (95% CI, 1.18-2.58; p = 0.006) times more likely to die on days with a mean PM₁₀ above the EU limit value of 50 μg/m3 than on days below this cutoff.
  
  
  CONCLUSIONS
  Even in an affluent region in Western Europe, where infant mortality is low, days with higher PM air pollution are associated with an increased risk of infant mortality. Assuming causality, the current EU limit value for PM₁₀, which may be exceeded on 35 days/year, does not prevent PM₁₀ from triggering mortality in late neonates.
authors.affiliation: Department of Public Health, Occupational and Environmental Medicine, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Hans
authors.initials: H
authors.lastname: Scheers
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Mwalili
authors.forename: Christel
authors.initials: C
authors.lastname: Faes
authors.forename: Frans
authors.initials: F
authors.lastname: Fierens
authors.forename: Benoit
authors.initials: B
authors.lastname: Nemery
authors.forename: Tim S
authors.initials: TS
authors.lastname: Nawrot
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D001530:Belgium / Q000453:epidemiology; D018592:Cross-Over Studies; D004781:Environmental Exposure; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D016014:Linear Models; D016017:Odds Ratio; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D018570:Risk Assessment; D012959:Socioeconomic Factors
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter