title: Short-term associations of cause-specific emergency hospitalizations and particulate matter chemical components in Hong Kong.
abstract: Despite an increasing number of recent studies, the overall epidemiologic evidence associating specific particulate matter chemical components with health outcomes has been mixed. The links between components and hospitalizations have rarely been examined in Asia. We estimated associations between exposures to 18 chemical components of particulate matter with aerodynamic diameter less than 10 μm (PM10) and daily emergency cardiorespiratory hospitalizations in Hong Kong, China, between 2001 and 2007. Carbonaceous particulate matter, sulfate, nitrate, and ammonium accounted for two-thirds of the PM10 mass. After adjustment for time-varying confounders, a 3.4-μg/m(3) increment in 2-day moving average of same-day and previous-day nitrate concentrations was associated with the largest increase of 1.32% (95% confidence interval: 0.73, 1.92) in cardiovascular hospitalizations; elevation in manganese level (0.02 μg/m(3)) was linked to a 0.91% (95% confidence interval: 0.19, 1.64) increase in respiratory hospitalizations. Upon further adjustment for gaseous copollutants, nitrate, sodium ion, chloride ion, magnesium, and nickel remained significantly associated with cardiovascular hospitalizations, whereas sodium ion, aluminum, and magnesium, components abundantly found in coarser PM10, were associated with respiratory hospitalizations. Most positive links were seen during the cold season. These findings lend support to the growing body of literature concerning the health associations of particulate matter composition and provide important insight into the differential health risks of components found in fine and coarse modes of PM10.
authors.forename: Vivian Chit
authors.initials: VC
authors.lastname: Pun
authors.forename: Ignatius Tak-Sun
authors.initials: IT
authors.lastname: Yu
authors.forename: Hong
authors.initials: H
authors.lastname: Qiu
authors.forename: Kin-Fai
authors.initials: KF
authors.lastname: Ho
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Sun
authors.forename: Peter K K
authors.initials: PK
authors.lastname: Louie
authors.forename: Tze Wai
authors.initials: TW
authors.lastname: Wong
authors.forename: Linwei
authors.initials: L
authors.lastname: Tian
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D064751:Ammonium Compounds / Q000009:adverse effects / Q000032:analysis; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D009566:Nitrates / Q000009:adverse effects / Q000032:analysis; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis; D012140:Respiratory Tract Diseases / Q000453:epidemiology / Q000209:etiology*; D013431:Sulfates / Q000009:adverse effects / Q000032:analysis; D014887:Weather
chemical_list: D000393:Air Pollutants; D064751:Ammonium Compounds; D009566:Nitrates; D052638:Particulate Matter; D013431:Sulfates
keywords: air pollution; chemical constituents; hospitalization; particulate matter; time series