title: Long-term exposure to fine particulate matter: association with nonaccidental and cardiovascular mortality in the agricultural health study cohort.
abstract: BACKGROUND
  Few studies have examined the relationship between long-term exposure to ambient fine particulate matter (PM2.5) and nonaccidental mortality in rural populations.
  
  
  OBJECTIVE
  We examined the relationship between PM2.5 and nonaccidental and cardiovascular mortality in the U.S. Agricultural Health Study cohort.
  
  
  METHODS
  The cohort (n = 83,378) included farmers, their spouses, and commercial pesticide applicators residing primarily in Iowa and North Carolina. Deaths occurring between enrollment (1993-1997) and 30 December 2009 were identified by record linkage. Six-year average (2001-2006) remote-sensing derived estimates of PM2.5 were assigned to participants' residences at enrollment, and Cox proportional hazards models were used to estimate hazard ratios (HR) in relation to a 10-μg/m(3) increase in PM2.5 adjusted for individual-level covariates.
  
  
  RESULTS
  In total, 5,931 nonaccidental and 1,967 cardiovascular deaths occurred over a median follow-up time of 13.9 years. PM2.5 was not associated with nonaccidental mortality in the cohort as a whole (HR = 0.95; 95% CI: 0.76, 1.20), but consistent inverse relationships were observed among women. Positive associations were observed between ambient PM2.5 and cardiovascular mortality among men, and these associations were strongest among men who did not move from their enrollment address (HR = 1.63; 95% 0.94, 2.84). In particular, cardiovascular mortality risk in men was significantly increased when analyses were limited to nonmoving participants with the most precise exposure geocoding (HR = 1.87; 95% CI: 1.04, 3.36).
  
  
  CONCLUSIONS
  Rural PM2.5 may be associated with cardiovascular mortality in men; however, similar associations were not observed among women. Further evaluation is required to explore these sex differences.
authors.affiliation: Health Canada, Air Health Sciences Division, Ottawa, Ontario, Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Weichenthal
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Villeneuve
authors.forename: Richard T
authors.initials: RT
authors.lastname: Burnett
authors.forename: Aaron
authors.initials: A
authors.lastname: van Donkelaar
authors.forename: Randall V
authors.initials: RV
authors.lastname: Martin
authors.forename: Rena R
authors.initials: RR
authors.lastname: Jones
authors.forename: Curt T
authors.initials: CT
authors.lastname: DellaValle
authors.forename: Dale P
authors.initials: DP
authors.lastname: Sandler
authors.forename: Mary H
authors.initials: MH
authors.lastname: Ward
authors.forename: Jane A
authors.initials: JA
authors.lastname: Hoppin
mesh_terms: D000328:Adult; D000383:Agriculture / Q000706:statistics & numerical data; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D002318:Cardiovascular Diseases / Q000401:mortality*; D015331:Cohort Studies; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007484:Iowa / Q000453:epidemiology; D008297:Male; D009026:Mortality; D009657:North Carolina / Q000453:epidemiology; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D012307:Risk Factors; D012424:Rural Population; D012737:Sex Factors
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter