AMBIENT PM₁₀ AND PM₂.₅ CONCENTRATIONS AT DIFFERENT HIGH TRAFFIC-RELATED STREET CONFIGURATIONS IN BANGKOK, THAILAND.

This study investigated the potential exposure levels of PM₁₀ and PM₂.₅ at two different road configuration sites in Bangkok, Thailand: covered and open roadside areas. One hundred samples were collected together with the meteorological data: temperature, relative humidity, wind speeds, and solar radiation. Spearman rank correlation was used to analyze the relationships between these factors, and PM₁₀ and PM₂.₅ levels at different roadside areas. The PM₁₀ and PM₂.₅ levels at the covered area were 1.72 and 1.60 times more than those levels at open area were. The mean levels were found to be 154.59 and 94.42 µg/m³ at the covered areas, and 89.43 and 58.69 µg/m³ at the open areas. These results suggested that a higher potential risk for workers, such as street vendors, was the exposure to particulate matters at the covered areas compared to open areas. Wind speeds and relative humidity were significantly negative-related influencing factors on PM₁₀ and PM₂.₅ levels at the open area, but not significantly related for the covered areas.