Finely Resolved On-Road PM 2.5 and Estimated Premature Mortality in Central North Carolina

Risk Anal. 2017 Dec;37(12):2420-2434. doi: 10.1111/risa.12775. Epub 2017 Feb 28.


To quantify the on-road PM2.5 -related premature mortality at a national scale, previous approaches to estimate concentrations at a 12-km × 12-km or larger grid cell resolution may not fully characterize concentration hotspots that occur near roadways and thus the areas of highest risk. Spatially resolved concentration estimates from on-road emissions to capture these hotspots may improve characterization of the associated risk, but are rarely used for estimating premature mortality. In this study, we compared the on-road PM2.5 -related premature mortality in central North Carolina with two different concentration estimation approaches-(i) using the Community Multiscale Air Quality (CMAQ) model to model concentration at a coarser resolution of a 36-km × 36-km grid resolution, and (ii) using a hybrid of a Gaussian dispersion model, CMAQ, and a space-time interpolation technique to provide annual average PM2.5 concentrations at a Census-block level (∼105,000 Census blocks). The hybrid modeling approach estimated 24% more on-road PM2.5 -related premature mortality than CMAQ. The major difference is from the primary on-road PM2.5 where the hybrid approach estimated 2.5 times more primary on-road PM2.5 -related premature mortality than CMAQ due to predicted exposure hotspots near roadways that coincide with high population areas. The results show that 72% of primary on-road PM2.5 premature mortality occurs within 1,000 m from roadways where 50% of the total population resides, highlighting the importance to characterize near-road primary PM2.5 and suggesting that previous studies may have underestimated premature mortality due to PM2.5 from traffic-related emissions.

Keywords: Air pollution; PM2.5; R-LINE; fine-resolution modeling; traffic-related mortality.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Air Pollution / adverse effects
  • Air Pollution / analysis
  • Female
  • Health Impact Assessment / statistics & numerical data
  • Humans
  • Male
  • Middle Aged
  • Models, Statistical
  • Mortality, Premature*
  • North Carolina / epidemiology
  • Particulate Matter / analysis
  • Particulate Matter / toxicity*
  • Risk Assessment / statistics & numerical data
  • Vehicle Emissions / analysis
  • Vehicle Emissions / toxicity*


  • Particulate Matter
  • Vehicle Emissions