Table 3.

Distributions of ${\mathrm{NO}}_2$ and ${\mathrm{PM}}_{2.5}$ in each pre- and postnatal window in the overall analytic sample from the three U.S. pregnancy cohorts in the ECHO-PATHWAYS consortium (the CANDLE, TIDES, and GAPPS study).

Exposures	Window	$n$	Min	1st quartile	Median	Mean (SD)	3rd quartile	Max
${\mathrm{NO}}_2$ (ppb)	1st trimester	1,935	1.59	6.01	8.62	8.96 (3.92)	11.49	33.74
	2nd trimester	1,934	1.44	5.66	7.97	8.45 (3.77)	10.82	29.15
	3rd trimester	1,920	1.19	5.56	7.91	8.36 (3.82)	10.56	33.53
	Overall pregnancy	1,932	1.74	6.36	8.35	8.62 (3.17)	10.65	27.29
	0–2 y	1,894	1.63	6.79	8.78	8.71 (2.93)	10.53	26.37
	2–4 y	1,894	1.61	6.46	8.68	8.59 (3.03)	10.50	25.93
${\mathrm{PM}}_{2.5}$ (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)	1st trimester	1,935	1.82	7.33	9.43	8.95 (2.7)	10.63	21.32
	2nd trimester	1,934	2.14	7.41	9.56	8.99 (2.74)	10.68	18.65
	3rd trimester	1,920	2.26	7.41	9.51	9.09 (2.93)	10.97	20.33
	Overall pregnancy	1,932	2.14	7.69	9.56	9 (2.32)	10.84	13.77
	0–2 y	1,894	3.03	7.41	9.54	8.75 (2.01)	10.28	12.04
	2–4 y	1,763	2.61	7.15	9.14	8.38 (1.79)	9.62	11.61

Note: CANDLE, Conditions Affecting Neurocognitive Development and Learning in Early Childhood; ECHO, Environmental Influences on Child Health Outcomes; GAPPS, Global Alliance to Prevent Prematurity and Stillbirth; min, minimum; max, maximum; SD, standard deviation; TIDES, The Infant Development and Environment Study.