Table 3.

Variance component (%) of NO₂ exposure levels estimated by the nearest-AQMS model and by the TAG model for various exposure windows and buffer sizes considered around AQMSs.

	Distance < 5 km (n = 681)				Distance < 2 km (n = 383)				Distance < 1 km (n = 146)
	Nearest-AQMS model		TAG model		Nearest-AQMS model		TAG model		Nearest-AQMS model		TAG model
Exposure window	Spatial	Temporal	Spatial	Temporal	Spatial	Temporal	Spatial	Temporal	Spatial	Temporal	Spatial	Temporal
First trimester	82	21	61	52	79	22	55	57	84	25	56	49
Second trimester	82	20	55	46	79	21	53	52	83	21	58	44
Third trimester	78	21	47	46	76	21	43	52	80	24	52	48
Pregnancy	95	7	92	14	91	8	92	17	97	9	92	13

The sum of variance components is > 100% because the data are not balanced as in experimental plans (i.e., the covariance is not null).