The main factors should be ventilation system and the amount of incense being burned. When compared with a study in ambient air of Chiang Mai (Pengchai et al., 2008, Chantara and Sangchan, 2009 and Wiriya et al., 2013), where 24-hrs PM10 samples were collected in urban and sub-urban areas. It was found that the ranges of TEQ values were 0.92–1.76 ng/m3 and 0.75–1.60 ng/m3 in urban area and 0.25–3.70 ng/m3 in sub-urban. It can be concluded that TEQ values calculated from ambient samples were much lower than the values reported in this study in every occasion.