Table 2.

Environmental exposure characteristics at the residential address of the children (n = 307)

	Mean (± SD)	Median	25th percentile	75th percentile
Surface area of green space within 6 buffers around the residence, %
50 m	49.1 ± 0.2	52	38	61
100 m	50.6 ± 0.2	53	40	61
300 m	51.2 ± 0.1	54	44	60
500 m	51.2 ± 0.1	53	44	61
1000 m	50.1 ± 0.1	53	49	57
2000 m	51.0 ± 0.2	56	48	59
Air pollution and traffic-related exposure
PM2.5, µg/m3	14.9 ± 1.0	14.9	14.2	15.7
NO2, µg/m3	20.9 ± 2.0	21.2	19.6	22.2
Distance to major road, m	552 ± 560	330	127	775