Long-range atmospheric transport of polycyclic aromatic hydrocarbons: a global 3-D model analysis including evaluation of Arctic sources

Environ Sci Technol. 2012 Sep 4;46(17):9501-10. doi: 10.1021/es301904d. Epub 2012 Aug 17.

Abstract

We use the global 3-D chemical transport model GEOS-Chem to simulate long-range atmospheric transport of polycyclic aromatic hydrocarbons (PAHs). To evaluate the model's ability to simulate PAHs with different volatilities, we conduct analyses for phenanthrene (PHE), pyrene (PYR), and benzo[a]pyrene (BaP). GEOS-Chem captures observed seasonal trends with no statistically significant difference between simulated and measured mean annual concentrations. GEOS-Chem also captures variability in observed concentrations at nonurban sites (r = 0.64, 0.72, and 0.74, for PHE, PYR, and BaP). Sensitivity simulations suggest snow/ice scavenging is important for gas-phase PAHs, and on-particle oxidation and temperature-dependency of gas-particle partitioning have greater effects on transport than irreversible partitioning or increased particle concentrations. GEOS-Chem estimates mean atmospheric lifetimes of <1 day for all three PAHs. Though corresponding half-lives are lower than the 2-day screening criterion for international policy action, we simulate concentrations at the high-Arctic station of Spitsbergen within four times observed concentrations with strong correlation (r = 0.70, 0.68, and 0.70 for PHE, PYR, and BaP). European and Russian emissions combined account for ~80% of episodic high-concentration events at Spitsbergen.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Air Pollutants / analysis*
  • Arctic Regions
  • Atmosphere / analysis*
  • Benzo(a)pyrene / analysis
  • Computer Simulation
  • Environmental Monitoring*
  • Models, Chemical
  • Oxidation-Reduction
  • Phenanthrenes / analysis
  • Polycyclic Aromatic Hydrocarbons / analysis*
  • Pyrenes / analysis
  • Seasons
  • Volatilization

Substances

  • Air Pollutants
  • Phenanthrenes
  • Polycyclic Aromatic Hydrocarbons
  • Pyrenes
  • Benzo(a)pyrene
  • phenanthrene
  • pyrene