title: Coarse particulate matter associated with increased risk of emergency hospital admissions for pneumonia in Hong Kong.
abstract: BACKGROUND
  Epidemiological research on the effects of coarse particles (PMc, particulate matter between 2.5 and 10 μm in aerodynamic diameter) on respiratory morbidity is sparse and inconclusive. Pneumonia is an inflammatory condition of lung caused by infections, which may be triggered and exacerbated by PMc exposure.
  
  
  OBJECTIVE
  To estimate the effect of PMc on emergency hospital admissions for pneumonia after controlling for PM(2.5) and gaseous pollutants.
  
  
  METHODS
  PMc concentrations were estimated by subtracting PM(2.5) from PM(10) measurements in each of the 10 air monitoring stations from January 2011 to December 2012 in Hong Kong and then citywide daily average concentrations of PMc were computed from the 10 stations. Generalised additive Poisson models were used to examine the relationship between PMc and daily emergency hospital admissions for pneumonia, adjusting for PM(2.5) and gaseous pollutants (NO(2), SO(2) and O(3)). Subgroup analyses by gender and age were also performed to identify the most susceptible subpopulations.
  
  
  RESULTS
  PMc and PM(2.5) were significantly associated with emergency pneumonia hospitalisations. Every 10 μg/m(3) increment of PMc in the past 4 days (lag0-lag3) was associated with a 3.33% (95% CI 1.54% to 5.15%) increase in emergency hospitalisations for pneumonia. The effect estimates of PMc were robust to the adjustment of PM(2.5), NO(2) or SO(2), but attenuated on the inclusion of O(3) in the model. Women, children and older people might be more vulnerable to PMc exposure.
  
  
  CONCLUSIONS
  Short-term PMc exposure is associated with emergency hospitalisations for pneumonia in Hong Kong. Air quality regulation specifically for PMc might be considered.
authors.affiliation: The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, ShaTin, Hong Kong.
authors.forename: Hong
authors.initials: H
authors.lastname: Qiu
authors.affiliation: The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, ShaTin, Hong Kong Shenzhen Municipal Key Laboratory for Health Risk Analysis, Shenzhen Research Institute of the Chinese University of Hong Kong, Shenzhen, China.
authors.forename: Lin Wei
authors.initials: LW
authors.lastname: Tian
authors.affiliation: The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, ShaTin, Hong Kong.
authors.forename: Vivian C
authors.initials: VC
authors.lastname: Pun
authors.affiliation: The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, ShaTin, Hong Kong Shenzhen Municipal Key Laboratory for Health Risk Analysis, Shenzhen Research Institute of the Chinese University of Hong Kong, Shenzhen, China.
authors.forename: Kin-Fai
authors.initials: KF
authors.lastname: Ho
authors.affiliation: The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, ShaTin, Hong Kong.
authors.forename: Tze Wai
authors.initials: TW
authors.lastname: Wong
authors.affiliation: The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, ShaTin, Hong Kong.
authors.forename: Ignatius T S
authors.initials: IT
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000009:adverse effects*; D010343:Patient Admission / Q000639:trends*; D011014:Pneumonia / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter