Table 1.

School characteristic.

School	Location	Sampling sites	Classroom shape	Classroom area (m2)	Number of students/ class	Environment condition
A	Pasar Baru, Central Jakarta	1st floor classroom (1) and school yard (1)	Rectangle	62.01	32	City center, business and office areas, next to main highway, near the intersection of red lights and the train station.
B	Lubang Buaya, East Jakarta	3rd floor classroom (1) and school yard (1)	Rectangle	64.8	36	Suburban, office and business areas, 100 m from the main highway and red light intersections.
C	Cipedak, South Jakarta	3rd floor classroom (1) and school yard (1)	Rectangle	64.74	36	Suburban, residential areas, and next to golf courses.
D	Kebon Jeruk, West Jakarta	3rd floor classroom (1) and school yard (1)	Rectangle	56.15	36	Suburban, business and residential areas, next to main highway, and the intersection of red lights.