The aim of this study was to characterize the PM2.5-bound polycyclic aromatic hydrocarbon (PAH) concentrations and their diagnostic ratios in an area impacted by light-duty vehicles fueled by neat ethanol and ethanol-blended gasoline. Samples were collected using a high-volume sampler, extracted, and analyzed for all 16 EPA-priority PAHs using gas chromatography/mass spectrometry (GC/MS) following the EPA 3550B Method. The most abundant PAHs were benzo[g,h,i]perylene, benzo[b]fluoranthene, benzo[a]pyrene and indeno[1,2,3-c,d]pyrene. The total mean concentration was 3.80 ± 2.88 ng m(-3), and the contribution of carcinogenic species was 58 ± 16 % of the total PAHs. The cumulative health hazard from the PAH mixture was determined, and the carcinogenic equivalents and mutagenic equivalents were 0.80 ± 0.82 and 1.17 ± 1.04 ng m(-3), respectively. Diagnostic ratios and normalized ratios were calculated for the individual samples.