Table 2.

Distributions of exposure measurements in the CANDLE cohort.

Measurements	$N$	Mean (SD)/percentage	Min	25th percentile	Median	75th percentile	Max	IQR
Prenatal exposures
${\mathrm{PM}}_{2.5}$ in the first trimester (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)	818	10.7 (1.5)	7.8	9.8	10.4	11.2	16.8	1.4
${\mathrm{PM}}_{2.5}$ in the second trimester (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)	818	10.7 (1.4)	7.7	9.9	10.5	11.4	16.6	1.5
${\mathrm{PM}}_{2.5}$ in the third trimester (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)	815	11.0 (1.7)	6.2	9.9	10.7	11.7	17.2	1.8
Prenatal ${\mathrm{PM}}_{2.5}$ (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)	818	10.8 (0.9)	8.6	10.2	10.8	11.3	13.8	1.1
Prenatal ${\mathrm{NO}}_2$ (ppb)	818	10.0 (2.4)	4.0	8.3	10.0	11.7	16.4	3.4
Distance to A1 roadway (m)	818	2,490 (1,841)	35	1,130	2,017	3,443	11,400	2,313
Distance to A2 roadway (m)	818	1,920 (1,631)	9	580	1,385	2,900	8,658	2,320
Distance to A3 roadway (m)	818	449 (542)	9	155	307	559	6,220	404
Proximity to any major roadwaya
$<150\mathrm{m}$	230	71.5%
$\ge 150\mathrm{m}$	588	28.0%
Missing	4	0.5%
Postnatal exposures
Postnatal ${\mathrm{PM}}_{2.5}$ (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^{-3}$)	780	9.9 (0.5)	8.7	9.5	9.8	10.2	11.6	0.7
Postnatal ${\mathrm{NO}}_2$ (ppb)	780	8.9 (1.9)	3.7	7.6	8.9	10.2	13.5	2.6
Distance to A1 roadway (m)	780	2,529 (2,013)	38	1,090	1,991	3,462	16,307	2,372
Distance to A2 roadway (m)	780	1,932 (1,609)	9	617	1,438	2,912	8,069	2,295
Distance to A3 roadway (m)	780	440 (452)	9	156	316	557	3,090	401
Proximity to any major roadwaya
$<150\mathrm{m}$	212	27.2%
$\ge 150\mathrm{m}$	568	72.8%

Note: IQR, interquartile range; ${\mathrm{NO}}_2$, nitrogen dioxide; ${\mathrm{PM}}_{2.5}$, ambient particulate matter (particulate matter $\le 2.5\mathrm{\mu }\mathrm{m}$ in aerodynamic diameter); SD, standard deviation.

^aProximity to major roadway was estimated based on the single address with the longest residential history in the pre- and postnatal window and was dichotomized at $150\mathrm{m}$ from any major roadway of A1, A2, or A3.