title: Atmospheric fine particulate matter and breast cancer mortality: a population-based cohort study.
abstract: Atmospheric fine particulate matter (PM2.5) has multiple adverse effects on human health. Global atmospheric levels of PM2.5increased by 0.55 μg/m3/year (2.1%/year) from 1998 through 2012. There is evidence of a causal relationship between atmospheric PM2.5and breast cancer (BC) incidence, but few studies have investigated BC mortality and atmospheric PM2.5. We investigated BC mortality in relation to atmospheric PM2.5levels among patients living in Varese Province, northern Italy.
  
  
  
  We selected female BC cases, archived in the local population-based cancer registry, diagnosed at age 50-69 years, between 2003 and 2009. The geographic coordinates of each woman's place of residence were identified, and individual PM2.5exposures were assessed from satellite data. Grade, stage, age at diagnosis, period of diagnosis and participation in BC screening were potential confounders. Kaplan-Meir and Nelson-Aalen methods were used to test for mortality differences in relation to PM2.5quartiles. Multivariable Cox proportional hazards modelling estimated HRs and 95% CIs of BC death in relation to PM2.5exposure.
  
  
  
  Of 2021 BC cases, 325 died during follow-up to 31 December 2013, 246 for BC. Risk of BC death was significantly higher for all three upper quartiles of PM2.5exposure compared to the lowest, with HRs of death: 1.82 (95% CI 1.15 to 2.89), 1.73 (95% CI 1.12 to 2.67) and 1.72 (95% CI 1.08 to 2.75).
  
  
  
  Our study indicates that the risk of BC mortality increases with PM2.5exposure. Although additional research is required to confirm these findings, they are further evidence that PM2.5exposure is harmful and indicate an urgent need to improve global air quality.
authors.affiliation: Cancer Registry Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Tagliabue
authors.affiliation: Environmental Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Borgini
authors.affiliation: Cancer Registry Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Tittarelli
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: van Donkelaar
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada.|Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA.
authors.forename: Randall V
authors.initials: RV
authors.lastname: Martin
authors.affiliation: Environmental Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Bertoldi
authors.affiliation: Cancer Registry Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Fabiano
authors.affiliation: Cancer Registry Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Maghini
authors.affiliation: Cancer Registry Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Codazzi
authors.affiliation: Environmental Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Scaburri
authors.affiliation: Environmental Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Imma
authors.initials: I
authors.lastname: Favia
authors.affiliation: Environmental Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cau
authors.affiliation: Cancer Registry Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Barigelletti
authors.affiliation: Local Health Unit, Province of Sondrio, Sondrio, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Tessandori
authors.affiliation: Environmental Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Contiero
mesh_terms: D000368:Aged; D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000009:adverse effects*; D001272:Atmosphere; D001943:Breast Neoplasms / Q000139:chemically induced / Q000401:mortality*; D004781:Environmental Exposure / Q000009:adverse effects*; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008875:Middle Aged; D052638:Particulate Matter / Q000009:adverse effects*; D016016:Proportional Hazards Models; D012189:Retrospective Studies
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: cancer registry; environment; particulate matter; prognosis; survival