title: Impact of ambient fine particulate matter carbon measurement methods on observed associations with acute cardiorespiratory morbidity.
abstract: Elemental carbon (EC) and organic carbon (OC) represent a substantial portion of particulate matter <2.5 μm in diameter (PM2.5), and have been associated with adverse health effects. EC and OC are commonly measured using the National Institute of Occupational Safety and Health (NIOSH) method or the Interagency Monitoring of Protected Visual Environments (IMPROVE) method. Measurement method differences could have an impact on observed epidemiologic associations. Daily speciated PM2.5 data were obtained from the St Louis-Midwest Supersite, and St Louis emergency department (ED) visit data were obtained from the Missouri Hospital Association for the period June 2001 to April 2003. We assessed acute associations between cardiorespiratory ED visits and EC and OC from NIOSH and IMPROVE methods using Poisson generalized linear models controlling for temporal trends and meteorology. Associations were generally similar for EC and OC from the different measurement methods. The most notable difference between methods was observed for congestive heart failure and EC (for example, warm season rate ratios (95% confidence intervals) per interquartile range change in EC concentration were: NIOSH=1.06 (0.99-1.13), IMPROVE=1.01 (0.96-1.07)). Overall, carbon measurement method had little impact on acute associations between EC, OC, and ED visits. Some specific differences were observed, however, which may be related to particle composition.
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Winquist
authors.affiliation: Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Jamie J
authors.initials: JJ
authors.lastname: Schauer
authors.affiliation: Environmental and Chemical Engineering, Washington University, St Louis, Missouri, USA.
authors.forename: Jay R
authors.initials: JR
authors.lastname: Turner
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
authors.forename: Mitch
authors.initials: M
authors.lastname: Klein
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
authors.forename: Stefanie Ebelt
authors.initials: SE
authors.lastname: Sarnat
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis; D002244:Carbon / Q000009:adverse effects* / Q000032:analysis; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D004636:Emergency Service, Hospital; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards; D006801:Humans; D016014:Linear Models; D008171:Lung Diseases / Q000453:epidemiology / Q000209:etiology*; D008923:Missouri / Q000453:epidemiology; D009314:National Institute for Occupational Safety and Health, U.S.; D010316:Particle Size; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis; D015203:Reproducibility of Results; D012621:Seasons; D014481:United States
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D002244:Carbon