The Long-term Characteristics of PM10 and PM2.5 in Bangkok, Thailand
Supanan Chirasophon, P. Pochanart
Abstract
Abstract The long-term characteristics of non-roadside (residential) PM 10 and PM 2.5 in Bangkok, Thailand was analyzed by using hourly concentrations of PM 10 and PM 2.5 which had been collected from 10 monitoring stations by the Pollution Control Department (PCD) of Thailand from 2006 to 2016. The results showed that most of the stations showed either the decreasing trend or no trend characters. The PM 2.5 and PM 10 during weekdays and dry season were higher than during weekends and wet season, respectively. The diurnal variations of both PM 2.5 and PM 10 exhibited multi-peaks characteristic, mostly 2 peaks during a day for PM 2.5 and 2 to 3 peaks depending on the locations for PM 10 . The PM 2.5 to PM 10 ratio of our residential monitoring stations was 0.61 in average which was in the same range as the PM 2.5 /PM 10 ratio from the roadside monitoring stations. This shows that the common sources of PM 2.5 and PM 10 at both types of monitoring station were similar, probably mainly from the traffic and transportations. However, it was found that PM 2.5 /PM 10 ratio during wet season was lower than during dry season indicating the role of emission sources and removal process in each season.