title: Air pollution exposure, cause-specific deaths and hospitalizations in a highly polluted Italian region.
abstract: BACKGROUND
  The Lombardy region in northern Italy ranks among the most air polluted areas of Europe. Previous studies showed air pollution short-term effects on all-cause mortality. We examine here the effects of particulate matter with aerodynamic diameter ≤10µm (PM10) and nitrogen dioxide (NO2) exposure on deaths and hospitalizations from specific causes, including cardiac, cerebrovascular and respiratory diseases.
  
  
  METHODS
  We considered air pollution, mortality and hospitalization data for a non-opportunistic sample of 18 highly polluted and most densely populated areas of the region in the years 2003-2006. We obtained area-specific effect estimates for PM10 and NO2 from a Poisson regression model on the daily number of total deaths or cause-specific hospitalizations and then combined them in a Bayesian random-effects meta-analysis. For cause-specific mortality, we applied a case-crossover analysis. Age- and season-specific analyses were also performed. Effect estimates were expressed as percent variation in mortality or hospitalizations associated with a 10µg/m(3) increase in PM10 or NO2 concentration.
  
  
  RESULTS
  Natural mortality was positively associated with both pollutants (0.30%, 90% Credibility Interval [CrI]: -0.31; 0.78 for PM10; 0.70%, 90%CrI: 0.10; 1.27 for NO2). Cardiovascular deaths showed a higher percent variation in association with NO2 (1.12%, 90% Confidence Interval [CI]: 0.14; 2.11), while the percent variation for respiratory mortality was highest in association with PM10 (1.64%, 90%CI: 0.35; 2.93). The effect of both pollutants was more evident in the summer season. Air pollution was also associated to hospitalizations, the highest variations being 0.77% (90%CrI: 0.22; 1.43) for PM10 and respiratory diseases, and 1.70% (90%CrI: 0.39; 2.84) for NO2 and cerebrovascular diseases. The effect of PM10 on respiratory hospital admissions appeared to increase with age. For both pollutants, effects on cerebrovascular hospitalizations were more evident in subjects aged less than 75 years.
  
  
  CONCLUSIONS
  Our study provided a sound characterization of air pollution exposure and its potential effects on human health in the most polluted, and also most populated and productive, Italian region, further documenting the need for effective public health policies.
authors.affiliation: Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Via San Barnaba, 8, 20122 Milan, Italy. Electronic address: michele.carugno@unimi.it.
authors.forename: Michele
authors.initials: M
authors.lastname: Carugno
authors.affiliation: Epidemiology Unit, Department of Preventive Medicine, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Via San Barnaba, 8, 20122 Milan, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Consonni
authors.affiliation: Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Via San Barnaba, 8, 20122 Milan, Italy.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Randi
authors.affiliation: Department of Statistics, Informatics and Applications "G. Parenti," University of Florence, Viale Morgagni, 59, 50134 Florence, Italy; Biostatistics Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo Il Vecchio, 2, 50139 Florence, Italy.
authors.forename: Dolores
authors.initials: D
authors.lastname: Catelan
authors.affiliation: Department of Statistics, Informatics and Applications "G. Parenti," University of Florence, Viale Morgagni, 59, 50134 Florence, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Grisotto
authors.affiliation: Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Via San Barnaba, 8, 20122 Milan, Italy; Epidemiology Unit, Department of Preventive Medicine, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Via San Barnaba, 8, 20122 Milan, Italy.
authors.forename: Pier Alberto
authors.initials: PA
authors.lastname: Bertazzi
authors.affiliation: Department of Statistics, Informatics and Applications "G. Parenti," University of Florence, Viale Morgagni, 59, 50134 Florence, Italy; Biostatistics Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo Il Vecchio, 2, 50139 Florence, Italy.
authors.forename: Annibale
authors.initials: A
authors.lastname: Biggeri
authors.affiliation: Department of Statistics, Informatics and Applications "G. Parenti," University of Florence, Viale Morgagni, 59, 50134 Florence, Italy; Biostatistics Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo Il Vecchio, 2, 50139 Florence, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Baccini
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D009026:Mortality; D009585:Nitrogen Dioxide / Q000633:toxicity; D052638:Particulate Matter / Q000633:toxicity
chemical_list: D052638:Particulate Matter; D009585:Nitrogen Dioxide
keywords: Air pollution; Bayesian analysis; Hospital admissions; Mortality; Nitrogen dioxide; Particulate matter