Table 3.

Change in logged blood lead level associated with a child’s residential proximity to airport using multiple linear regression (n = 125,197).

Within distance buffersa				Categorical distance measure
Covariate	Coefficient (95% CI)		Covariate	Coefficient (95% CI)
Unadjusted
Within 500 m		0.089	(0.034 to 0.144)#		Between 0 and 500 m		0.094	(0.038 to 0.150)#
Within 1,000 m		0.084	(0.036 to 0.133)#		Between 501 and 1,000 m		0.085	(0.027 to 0.142)#
Within 1,500 m		0.077	(0.039 to 0.116)#		Between 1,001 and 1,500 m		0.071	(0.023 to 0.119)#
Within 2,000 m		0.052	(0.018 to 0.087)#		Between 1,501 and 2,000 m		0.016	(–0.022 to 0.053)
					> 2,000 m		Reference
Adjustedb
Within 500 m		0.043	(0.006 to 0.080)**		Between 0 and 500 m		0.043	(0.006 to 0.080)**
Within 1,000 m		0.037	(0.010 to 0.065)#		Between 501 and 1000 m		0.034	(–0.003 to 0.072)*
Within 1,500 m		0.021	(0.0008 to 0.041)**		Between 1,001 and 1,500 m		0.007	(–0.020 to 0.034)
Within 2,000 m		0.003	(–0.013 to 0.020)		Between 1,501 and 2,000 m		–0.019	(–0.041 to 0.003)*
					> 2,000 m		Reference
aWithin-distance thresholds were entered in separate regression models. bAdjusted models control for census block level proportion black and proportion Hispanic, census block group level percent population receiving public assistance and household median income, as well as individual level dummy variables for the season in which a child was screened for blood lead. *p < 0.10. **p < 0.05. #p < 0.01.