The simulation results by the AERMOD modeling system were next compared with the monitoring results by
the receptors. At the receptors 2 and 6 about 1 to 5 km
from the reference point, the simulation results for the
dry season showed peaks of higher NO2 concentration
compared with the receptor 11 located 7.5 km away from
the reference point. The monitoring and simulation results
showed almost the same trend. In case of wet season,
NO2 concentration peaks were found at the receptor 6
but a few at the receptors 2 and 11. According to safety
thresholds for 1-hr average, NO2 concentrations issued
by the NAAQS (320 μg/m3; PCD, 1995) and by the
Guidelines of WHO (200 μg/m3; WHO, 2005), most of
NO2 emissions from the cement complex, as indicated both
by measurement and the AERMOD simulation, showed
no significant impact on nearby communities. However,
it is worth noting that the NO2 emissions and monitoring