The overall metals
measure was positively associated with
maternal parents’ education, tract median
income, tract percent college educated, family
income, and the 1990 HAP model year
and negatively associated with year of birth
and the 1996 and 1999 HAP model years
[see Supplemental Material, Table S2 (http://
dx.doi.org/10.1289/ehp.1206187)].