Table 6.

Percent change in pollutant level per increase of one interquartile range in the indicated predictor stratified by whether the communities are in or out of the Los Angeles basin.

Predictor variable	NO2		NO		NOX
	In basin	Out of basin	In basin	Out of basin	In basin	Out of basin
	% Change	% Change	% Change	% Change	% Change	% Change
CALINE-modeled TRP (freeway)	8.6****	16.3****	19.8****	31.1****	14.1****	20.9****
CALINE-modeled TRP (non-freeway)	3.9****	11.8****	14.1****	25.4****	10.4****	15.6****
Distance to nearest freeway	−0.6	1.2	−1.1	−0.1	−1.6	−1.9
Squared distance to nearest freeway	−0.3	0.4	0.9	0.3	0.5	−0.1
Distance to nearest non-freeway major road	−0.7	−2.7***	−2.6**	−2.4**	−1.1*	−2.9****
Non-freeway traffic volume within a 300m buffer	1.5****	−0.5	1.2	−6.3**	1.0*	−2.0
Population within a 300m buffer	1.2****	1.3	3.2****	−1.0	2.3	1.2
Neighborhood elevation relative to the community	−2.5****	−9.5****	−4.3****	−8.2****	−1.8***	−10.5****
LRT fixed versus spatial model	229.9****	38.2	248.8	32.7****	350.8****	35.5****
10-fold cross-validation R2	69%	72%	60%	72%	70%	76%

In-basin includes 658 sampling locations in eight communities within the Los Angeles basin. Out of basin includes 284 sampling locations in four communities outside the LA basin (see Table 1 for the specific communities). See Table 4 for the IQRs of the predicted variables.

^*P<0.1;

^**P<0.05;

^***P<0.005;

^****P<0.0005.