Table 1.

The characteristics of participants.

	All	Age ≤27	Age >27	P
N	1,121	616	505
Age (years)	28.17 ± 0.29	23.32 ± 0.13	33.05 ± 0.30	<0.001
Race/ethnicity ( n , %)				0.14
Non-Hispanic white	52.74	49.46	55.73
Non-Hispanic black	15.49	18.76	12.87
Mexican American	16.20	18.10	14.28
Other Hispanic	5.55	5.93	5.30
Other races	10.03	7.75	11.82
Education ( n , %)				<0.001
Below high school	19.45	28.64	10.80
High school	18.89	26.08	12.13
Above high school	61.66	45.28	77.06
PIR levels (%)				<0.001
<1.33	26.36	35.82	19.15
1.33–3.5	31.56	37.10	25.76
≥3.5	42.07	27.08	55.09
Blood lead (ug/dL)	0.73 ± 0.03	0.73 ± 0.04	0.73 ± 0.03	0.94
High blood lead (%)	2.53	2.72	2.39	0.78

Weighted analysis was performed. High blood lead is defined as blood lead >2 ug/dL. PIR, poverty-to-income ratio.