Abstract
Hourly averaged PM2.5 and optical black carbon (OBC) were measured from 30 September to 10 October 2003 at roadside of Route 23 in Nagoya City. The average PM2.5 concentration was 76.5 μg/m3 (n=234). The average OBC concentration was 15.5μg/m3 (n=241). OBC average contribution to PM2.5 mass was 22.3%. There was a strong correlation between OBC and the traffic volume for heavy-duty vehicle when a roadside site was downwind of Route 23 and wind velocity was above 3m/s. EC emission factor was estimated at 368mg/km·vehicle for heavy-duty vehicle using NOx emission facto and 261mg/km·vehicle for heavy-duty vehicle based on dispersion calculation.
Daily averaged PM2.5 and elemental carbon (EC) were measural from January 2005 to December 2006 at an urban site in Nagoya city. The average PM2.5 concentrations in 2005 and 2006 were 23.1μg/m3 (n= 193), and 24.6μg/m3 (n=182), respectively. The average EC concentrations in 2005 and 2006 were both 32μg/m3. Average contributions of EC to PM2.5 in 2005 and 2006 were 15% and 14%, respectively. The average EC concentrations on weekday and on Sunday were 3.5μg/m3 and 2.0μg/m3, respectively, and EC on Sunday was 40% lower than that on weekday. The calculated concentrations of monthly average EC by ADMER (Atmospheric Dispersion Model for Exposure and Risk Assessment) at the urban site was similar to the observed concentrations.
