in the classroom, levels are approximately three-foldhigher in Bangkok than in Chonburi.
In terms of PAHs, ambient levels measured at the roadsides in front of schools in Bangkok are more than30-fold higher than in Chonburi. In school playgrounds, the levels are 12-fold higher in Bangkok than in Chon- buri, and in the classrooms, levels are approximately 8-fold higher in Bangkok than in Chonburi.