Measurements and Analysis of Polycyclic Aromatic Hydrocarbons near a Major Interstate

Abstract

Polycyclic aromatic hydrocarbons were measured near Interstate 40, just east of Research Triangle Park, North Carolina. One hundred seven 8-h integrated samples were collected on 20 sampling days over a 2 month period in Fall 2014. The 8-h samples were collected by low flow (16.7 L/min) fine particulate samplers. The samples were analyzed using gas chromatography-mass spectrometry. Temporal distribution of the PAHs (0.1-21.6 ng/m 3 ± 9.0 std) were compared to meteorological and pollutant data collected at the near roadway station. There is a weak but significant correlation between the sum of the measured PAHs with ozone, nitrogen dioxide and nitric oxide, with the R 2 values being 0.0049, 0.0187 and 0.0788 respectively. However the p-values (α = 0.05) were 0.044, 0.002 and 0.044, which are significant. Wind rose analysis illustrated the morning hours which were predominantly southern winds, while the afternoon hours illustrated southerly and easterly winds, which suggests that the automobile traffic as the main source of PAHs. The nighttime hours wind rose shows winds from northerly and easterly direction, which are predominantly from the RDU International Airport. PAH concentration found in this study compare favorably to other research studies (0.1 to 193.6 ng/m 3 ) both nationally and internationally.