title: Effects of particulate matter exposure on multiple sclerosis hospital admission in Lombardy region, Italy.
abstract: BACKGROUND
  Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating disease of the central nervous system, characterized by recurrent relapses of inflammation that cause mild to severe disability. Exposure to airborne particulate matter (PM) has been associated with acute increases in systemic inflammatory responses and neuroinflammation. In the present study, we hypothesize that exposure to PM<10μm in diameter (PM10) might increase the occurrence of MS-related hospitalizations.
  
  
  METHODS
  We obtained daily concentrations of PM10 from 53 monitoring sites covering the study area and we identified 8287 MS-related hospitalization through hospital admission-discharge records of the Lombardy region, Italy, between 2001 and 2009. We used a Poisson regression analysis to investigate the association between exposure to PM10 and risk of hospitalization.
  
  
  RESULTS
  A higher RR of hospital admission for MS relapse was associated with exposure to PM10 at different time intervals. The maximum effect of PM10 on MS hospitalization was found for exposure between days 0 and 7: Hospital admission for MS increased 42% (95%CI 1.39-1.45) on the days preceded by one week with PM10 levels in the highest quartile. The p-value for trend across quartiles was<0.001.
  
  
  CONCLUSIONS
  These data support the hypothesis that air pollution may have a role in determining MS occurrence and relapses. Our findings could open new avenues for determining the pathogenic mechanisms of MS and potentially be applied to other autoimmune diseases.
authors.affiliation: EPIGET-Epidemiology, Epigenetics and Toxicology Lab - Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Via San Barnaba 8, 20122 Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Angelici
authors.affiliation: Neurology Unit, Azienda Ospedaliera Fatebenefratelli e Oftalmico, Milano, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: Piola
authors.affiliation: EPIGET-Epidemiology, Epigenetics and Toxicology Lab - Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Via San Barnaba 8, 20122 Milan, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Cavalleri
authors.affiliation: EPIGET-Epidemiology, Epigenetics and Toxicology Lab - 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: Epidemiology Unit, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cortini
authors.affiliation: Multiple Sclerosis Center, Department of Clinical Neurology, Neurological Institute 'C. Mondino', Pavia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Bergamaschi
authors.affiliation: Exposure, Epidemiology and Risk Program, Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Baccarelli
authors.affiliation: EPIGET-Epidemiology, Epigenetics and Toxicology Lab - Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Via San Barnaba 8, 20122 Milan, Italy; Epidemiology Unit, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Pier Alberto
authors.initials: PA
authors.lastname: Bertazzi
authors.affiliation: EPIGET-Epidemiology, Epigenetics and Toxicology Lab - Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Via San Barnaba 8, 20122 Milan, Italy; Epidemiology Unit, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Angela Cecilia
authors.initials: AC
authors.lastname: Pesatori
authors.affiliation: EPIGET-Epidemiology, Epigenetics and Toxicology Lab - Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Via San Barnaba 8, 20122 Milan, Italy; Epidemiology Unit, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy. Electronic address: valentina.bollati@unimi.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Bollati
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis* / Q000633:toxicity; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects / Q000032:analysis*; D007558:Italy; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000209:etiology; D010316:Particle Size; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis*; D016012:Poisson Distribution; D012306:Risk; D012621:Seasons; D013383:Suburban Population / Q000706:statistics & numerical data; D014505:Urban Population / Q000706:statistics & numerical data; D014887:Weather
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Air pollution; Lombardy region; MS hospitalization; Multiple Sclerosis; PM(10)