The contribution of secondhand tobacco smoke to blood lead levels in US children and adolescents: a cross-sectional analysis of NHANES 2015–2018

Table 3 Adjusted^a geometric means of BLL and ratio of GMs among US children and adolescents

Characteristics	Blood Lead Level, μg/dL (GMs, 95%)	Ratio of GMs (95% CI)	p-value	p-trend^b
Total	0.46 (0.44, 0.49)
Serum cotinine levels				< 0.001
< 0.03 ng/mL	0.41 (0.38, 0.43)	1.00
0.03–3	0.48 (0.45, 0.51)	1.18 (1.12, 1.24)	< 0.001
> 3	0.52 (0.46, 0.59)	1.29 (1.13, 1.46)	< 0.001
Gender				< 0.001
Female	0.43 (0.40, 0.45)	1.00
Male	0.51 (0.48, 0.55)	1.20 (1.15, 1.26)	< 0.001
Age
6–10	0.52 (0.50, 0.55)	1.00		< 0.001
11–15	0.47 (0.44, 0.50)	0.89 (0.84, 0.95)	< 0.001
16–19	0.41 (0.38, 0.45)	0.79 (0.73, 0.85)	< 0.001
Race/ethnicity				0.264
Non-Hispanic White	0.49 (0.45, 0.53)	1.00
Non-Hispanic Black	0.47 (0.44, 0.51)	0.97 (0.88, 1.06)	0.433
Hispanic	0.44 (0.40, 0.48)	0.90 (0.82, 0.99)	0.031
Other	0.47 (0.43, 0.51)	0.96 (0.86, 1.07)	0.455
Central Obesity				< 0.001
No	0.49 (0.46, 0.52)	1.00
Yes	0.44 (0.41, 0.47)	0.90 (0.86, 0.94)	< 0.001
Education				0.215
Less than High School	0.45 (0.43, 0.47)	1.00
High school or some college	0.47 (0.44, 0.50)	1.04 (0.97, 1.12)	0.084
College graduate or above	0.49 (0.43, 0.55)	1.08 (0.94, 1.25)	0.057
Poverty Income Ratio				< 0.001
< 1.3	0.52 (0.48, 0.56)	1.00
1.3–3.5	0.48 (0.45, 0.51)	0.92 (0.87, 0.97)	< 0.001
> 3.5	0.41 (0.38, 0.44)	0.79 (0.73, 0.86)	< 0.001

^aAdjusted for gender, age, race/ethnicity, central obesity, education of reference person in the household, and poverty-to-income ratio;
^bp values for trend were estimated to assess dose–response effect across categories of serum cotinine levels in the regression models

ISSN: 1471-2458