Abstract:
Fine particulate matters, PM₁₀ and PM₂ ̣₅ at Bangkok mass transit system (BTS) stations: Phayathai, Phakanong and Chongnonthee were sampled with personal air sampler attached impactor cascade heads. The particulate concentrations were measured by Gravimetric method using an electronic microbalance. The co-measurements were conducted parallely with β ̵ attenuation (for PM₁₀) and R&P single channel sampler (for PM₂ ̣₅) at PCD monitoring station. The result at Dindaeng station showed significant correlation with equation: PM₁₀ (Cascade) = 1.2424 PM₁₀ (Beta ̵attenuation), r² = 0.8610 and PM₂ ̣₅(Cascade) = 1.2593 PM₂ ̣₅ (R&P single channel sampler), r² = 0.9594. The 24-hr average fine particulate matters in workday were higher than those of 24-hr average in weekend. The PM concentrations were found increasing with the traffic volume under BTS stations. The vertical PM levels decreased with the increasing height, particularly at Prakanong station. The mean PM₂ ̣₅ to PM₁₀ ratio at all stations were between 0.56 ̵ 0.69. The regression analysis for correlation between particulate matter concentrations and their influential factors at BTS stations found that PM concentrations related to traffic volume, atmospheric pressure, temperature and the construction structure of the BTS stations.