title: Impact of fine and ultrafine particles on emergency hospital admissions for cardiac and respiratory diseases.
abstract: BACKGROUND
  Little is known about the short-term effects of ultrafine particles.
  
  
  METHODS
  We evaluated the effect of particulate matter with an aerodynamic diameter <or=10 microm (PM10), <or=2.5 microm (PM2.5), and ultrafine particles on emergency hospital admissions in Rome 2001-2005. We studied residents aged >or=35 years hospitalized for acute coronary syndrome, heart failure, lower respiratory tract infections, and chronic obstructive pulmonary disease (COPD). Information was available for factors indicating vulnerability, such as age and previous admissions for COPD. Particulate matter data were collected daily at one central fixed monitor. A case-crossover analysis was performed using a time-stratified approach. We estimated percent increases in risk per 14 microg/m PM10, per 10 microg/m PM2.5, and per 9392 particles/mL.
  
  
  RESULTS
  An immediate impact (lag 0) of PM2.5 on hospitalizations for acute coronary syndrome (2.3% [95% confidence interval = 0.5% to 4.2%]) and heart failure (2.4% [0.3% to 4.5%]) was found, whereas the effect on lower respiratory tract infections (2.8% [0.5% to 5.2%]) was delayed (lag 2). Particle number concentration showed an association only with admissions for heart failure (lag 0-5; 2.4% [0.2% to 4.7%]) and COPD (lag 0; 1.6% [0.0% to 3.2%]). The effects were generally stronger in the elderly and during winter. There was no clear effect modification with previous COPD.
  
  
  CONCLUSIONS
  We found sizeable acute health effects of fine and ultrafine particles. Although differential reliability in exposure assessment, in particular of ultrafine particles, precludes a firm conclusion, the study indicates that particulate matter of different sizes tends to have diverse outcomes, with dissimilar latency between exposure and health response.
authors.affiliation: Department of Epidemiology, Rome E Health Authority, Rome, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Belleudi
authors.forename: Annunziata
authors.initials: A
authors.lastname: Faustini
authors.forename: Massimo
authors.initials: M
authors.lastname: Stafoggia
authors.forename: Giorgio
authors.initials: G
authors.lastname: Cattani
authors.forename: Achille
authors.initials: A
authors.lastname: Marconi
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Perucci
authors.forename: Francesco
authors.initials: F
authors.lastname: Forastiere
mesh_terms: D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006331:Heart Diseases / Q000453:epidemiology*; D006801:Humans; D038801:International Classification of Diseases; D007558:Italy; D008875:Middle Aged; D010316:Particle Size; D010343:Patient Admission / Q000639:trends*; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology*; D012141:Respiratory Tract Infections / Q000453:epidemiology*
chemical_list: D000393:Air Pollutants