title: Particulate matter and daily mortality: a case-crossover analysis of individual effect modifiers.
abstract: BACKGROUND
  Several time-series studies have established the relationship between particulate matter (PM10) and mortality. We adopted a case-crossover design to evaluate whether individual socio-demographic characteristics and chronic or acute medical conditions modify the PM10-mortality association.
  
  
  METHODS
  We selected all natural deaths (321,024 subjects) occurring among adult (aged 35+ years) residents of 9 Italian cities between 1997 and 2004. We had access to individual information on socio-demographic variables, location of death, and chronic conditions (hospital admissions in the preceding 2-year period). For in-hospital deaths, we collected information on treatment wards at time of death and acute medical conditions. In a case-crossover analysis we adjusted for time, population changes, and meteorological conditions.
  
  
  RESULTS
  PM10 was associated with mortality among subjects age 65 years and older (0.75% increase per 10 microg/m3 [95% confidence interval = 0.42% to 1.09%]), with a more pronounced effect among people age 85 and older. A weaker effect was found among the most affluent people. The effect was present for both out-of-hospital and in-hospital deaths, especially among those treated in general medicine and other less specialized wards. PM10 effects were stronger among people with diabetes (1.03% [0.28% to 1.79%]) and chronic obstructive pulmonary disease (0.84% [0.17% to 1.52%]). The acute conditions with the largest effect estimates were acute impairment of pulmonary circulation (4.56% [0.75% to 8.51%]) and heart failure (1.67% [0.30% to 3.04%]).
  
  
  CONCLUSIONS
  Several factors, including advanced age, type of hospital ward, and chronic and acute health conditions, modify the PM10-related risk of death. Altered pulmonary circulation and heart failure are important effect modifiers, suggesting that cardiac decompensation is a possible mechanism of the fatal PM10 effect.
authors.affiliation: Department of Epidemiology, Rome E Health Authority, Rome, Italy. forastiere@asplazio.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Forastiere
authors.forename: Massimo
authors.initials: M
authors.lastname: Stafoggia
authors.forename: Giovanna
authors.initials: G
authors.lastname: Berti
authors.forename: Luigi
authors.initials: L
authors.lastname: Bisanti
authors.forename: Achille
authors.initials: A
authors.lastname: Cernigliaro
authors.forename: Monica
authors.initials: M
authors.lastname: Chiusolo
authors.forename: Sandra
authors.initials: S
authors.lastname: Mallone
authors.forename: Rossella
authors.initials: R
authors.lastname: Miglio
authors.forename: Paolo
authors.initials: P
authors.lastname: Pandolfi
authors.forename: Magda
authors.initials: M
authors.lastname: Rognoni
authors.forename: Maria
authors.initials: M
authors.lastname: Serinelli
authors.forename: Roberta
authors.initials: R
authors.lastname: Tessari
authors.forename: Mariangela
authors.initials: M
authors.lastname: Vigotti
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Perucci
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis*; D002908:Chronic Disease / Q000453:epidemiology; D018592:Cross-Over Studies; D019992:Databases as Topic; D003710:Demography; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D010316:Particle Size; D018570:Risk Assessment; D014505:Urban Population; D014887:Weather
chemical_list: D000393:Air Pollutants