title: Public health impacts of secondary particulate formation from aromatic hydrocarbons in gasoline.
abstract: BACKGROUND
  Aromatic hydrocarbons emitted from gasoline-powered vehicles contribute to the formation of secondary organic aerosol (SOA), which increases the atmospheric mass concentration of fine particles (PM2.5). Here we estimate the public health burden associated with exposures to the subset of PM2.5 that originates from vehicle emissions of aromatics under business as usual conditions.
  
  
  METHODS
  The PM2.5 contribution from gasoline aromatics is estimated using the Community Multiscale Air Quality (CMAQ) modeling system and the results are compared to ambient measurements from the literature. Marginal PM2.5 annualized concentration changes are used to calculate premature mortalities using concentration-response functions, with a value of mortality reduction approach used to monetize the social cost of mortality impacts. Morbidity impacts are qualitatively discussed.
  
  
  RESULTS
  Modeled aromatic SOA concentrations from CMAQ fall short of ambient measurements by approximately a factor of two nationwide, with strong regional differences. After accounting for this model bias, the estimated public health impacts from exposure to PM2.5 originating from aromatic hydrocarbons in gasoline lead to a central estimate of approximately 3800 predicted premature mortalities nationwide, with estimates ranging from 1800 to over 4700 depending on the specific concentration-response function used. These impacts are associated with total social costs of $28.2B, and range from $13.6B to $34.9B in 2006$.
  
  
  CONCLUSIONS
  These preliminary quantitative estimates indicate particulates from vehicular emissions of aromatic hydrocarbons demonstrate a nontrivial public health burden. The results provide a baseline from which to evaluate potential public health impacts of changes in gasoline composition.
authors: Harvard Center for Risk Analysis, 401 Park Drive, Landmark 404J, Boston, MA 02215, USA. kvon@hsph.harvard.edu
authors: Katherine
authors: K
authors: von Stackelberg
authors: Jonathan
authors: J
authors: Buonocore
authors: Prakash V
authors: PV
authors: Bhave
authors: Joel A
authors: JA
authors: Schwartz
mesh_terms: D000336:Aerosols / Q000032:analysis / Q000633:toxicity*; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D006841:Hydrocarbons, Aromatic / Q000032:analysis / Q000633:toxicity*; D008962:Models, Theoretical; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity; D011634:Public Health; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D006841:Hydrocarbons, Aromatic; D052638:Particulate Matter; D001335:Vehicle Emissions