. 2009 Jul 2;6(7):1930–1946. doi: 10.3390/ijerph6071930

Table 4.

Geometric Means and P-values Overall and by Level of Smoke Exposure and Demographic Characteristics for Lead (Pb).

Heavy Metal	Creatinine Adjustment	Overall Geometric Mean Pb level	Nonsmokers			Smokers	P-value^a
Heavy Metal	Creatinine Adjustment	Overall Geometric Mean Pb level	Geometric Mean Pb level without SHS	Geometric Mean Pb level with Low SHS	Geometric Mean Pb level with High SHS	Geometric Mean Pb level	P-value^a
AGE (years)
2:[6–12)^b	Adjusted^c	0.97 (0.90,1.03)	0.85 (0.77,0.93)	0.89(0.80,0.99)^g	1.17(1.03,1.30)^h	n/a^d	0.0005
	Unadjusted^e	0.87 (0.79,0.94)	0.78 (0.69,0.87)	0.79 (0.67,0.91)	1.04(0.87,1.20)^f	n/a	0.0153
3:[12–19)	Adjusted	0.43 (0.41,0.44)	0.39(0.36,0.42)^f	0.48 (0.43,0.53)	0.44 (0.39,0.49)	0.42 (0.38,0.46)	0.0390
	Unadjusted	0.59 (0.55,0.62)	0.49(0.45,0.54)^g	0.67 (0.58,0.77)	0.66 (0.58,0.75)	0.63(0.53,0.73)^f	0.0008
4:[19–35)	Adjusted	0.48 (0.45,0.51)	0.42 (0.38,0.46)	0.48 (0.43,0.52)	0.47 (0.40,0.53)	0.56(0.50,0.61)^h	0.0005
	Unadjusted	0.61 (0.56,0.65)	0.48 (0.42,0.54)	0.59 (0.52,0.67)	0.66 (0.52,0.79)	0.76(0.65,0.87)^h	0.0001
5:[ 35–50)	Adjusted	0.65 (0.61,0.69)	0.56 (0.51,0.61)	0.59 (0.53,0.65)	0.64(0.54,0.74)^g	0.84(0.75,0.94)^h	0.0000
	Unadjusted	0.66 (0.61,0.71)	0.55 (0.50,0.60)	0.64 (0.52,0.77)	0.65 (0.52,0.79)	0.84(0.75,0.93)^h	0.0000
6:[50–65)	Adjusted	0.80 (0.75,0.85)	0.72 (0.67,0.78)	0.83 (0.75,0.91)	0.81 (0.67,0.95)	0.96(0.85,1.08)^h	0.0002
	Unadjusted	0.71 (0.64,0.78)	0.62 (0.55,0.68)	0.74 (0.64,0.85)	0.67 (0.42,0.92)	0.94(0.78,1.10)^h	0.0001
7:[65+)	Adjusted	0.91 (0.87,0.95)	0.88 (0.83,0.93)	0.92 (0.84,1.00)	0.99 (0.80,1.18)	1.11(0.96,1.26)^f	0.0318
	Unadjusted	0.72 (0.66,0.77)	0.64(0.59,0.70)^f	0.81 (0.70,0.92)	0.79 (0.62,0.97)	0.98(0.82,1.15)^h	0.0008
RACE/ETHNICITY
Non-Hispanic White	Adjusted	0.64 (0.62,0.66)	0.59(0.56,0.63)^f	0.66 (0.62,0.69)	0.63 (0.57,0.70)	0.71(0.66,0.76)^g	0.0011
	Unadjusted	0.61 (0.58,0.64)	0.54(0.51,0.57)^f	0.64 (0.58,0.70)	0.65 (0.55,0.74)	0.72(0.65,0.78)^h	0.0001
Non-Hispanic Black	Adjusted	0.66 (0.61,0.71)	0.55 (0.50,0.59)	0.59(0.54,0.64)^h	0.73 (0.64,0.82)	0.82(0.71,0.92)^h	0.0000
	Unadjusted	0.96 (0.89,1.03)^k	0.76 (0.69,0.83)^k	0.83(0.72,0.94)^f,^j	1.04(0.92,1.16)^f,^k	1.34(1.19,1.50)^h,^k	0.0000
Mexican American	Adjusted	0.81 (0.77,0.86)^k	0.79 (0.75,0.83)^k	0.83 (0.76,0.91)^k	0.79 (0.64,0.93)	0.89 (0.75,1.03)ⁱ
	Unadjusted	0.87 (0.81,0.92)^k	0.79 (0.72,0.85)^k	0.94 (0.82,1.06)^k	0.87 (0.76,0.97)^j	1.13(0.95,1.30)^h,^k	0.0002
GENDER
Male	Adjusted	0.65 (0.62,0.67)	0.56(0.53,0.59)^h	0.70 (0.65,0.76)	0.67 (0.59,0.74)	0.73(0.68,0.77)^h	0.0000
	Unadjusted	0.80 (0.76,0.84)	0.69(0.64,0.73)^h	0.87 (0.78,0.96)	0.78 (0.65,0.92)	0.95(0.86,1.04)^h	0.0000
Female	Adjusted	0.67 (0.64,0.69)	0.65 (0.61,0.68)^k	0.63 (0.60,0.67)ⁱ	0.69 (0.62,0.75)	0.74 (0.67,0.82)	0.0494
	Unadjusted	0.58 (0.55,0.60)^k	0.51 (0.48,0.54)^k	0.56(0.50,0.61)^f,^k	0.70 (0.61,0.79)	0.70(0.62,0.77)^h,^k	0.0000
POVERTY INDEX
Below poverty index	Adjusted	0.74 (0.68,0.79)	0.70 (0.62,0.78)	0.70 (0.61,0.78)	0.81 (0.69,0.94)	0.73 (0.64,0.83)
	Unadjusted	0.84 (0.78,0.91)	0.68 (0.59,0.77)	0.83 (0.72,0.95)	0.95 (0.81,1.09)	0.93(0.80,1.07)^f	0.0015
Above poverty index	Adjusted	0.63 (0.61,0.65)	0.59(0.56,0.62)^f	0.65 (0.61,0.68)	0.64 (0.58,0.69)	0.72(0.66,0.77)^h	0.0007
	Unadjusted	0.63 (0.61,0.66)	0.56(0.53,0.59)^g	0.65 (0.60,0.71)	0.68(0.60,0.77)^f	0.78(0.70,0.86)^h	0.0000

^{^a}

A statistically significant difference in log transformed mean levels between the exposure groups (nonsmoker, nonsmoker_low, nonsmoker_high, smoker) determined by linear regression.

^{^b}

For age categories, a square bracket indicates inclusion of the interval end point, and a parenthesis indicates exclusion.

^{^c}

Units are μg/g creatinine.

^{^d}

Not applicable.

^{^e}

Units are μg/L.

For statistical analysis of differences in mean urine metal levels the following t-tests comparisons were performed: nonsmokers and nonsmokers_low; nonsmokers_low and nonsmokers_high; nonsmokers_high and smokers; smokers and nonsmokers; and nonsmoker vs. nonsmoker_high for children aged 6–11 years.

^{^f}

p-value less than 0.05;

^{^g}

p-value less than 0.01;

^{^h}

p-value less than 0.001. For statistical analysis of differences in mean urine lead levels across group comparisons, the following t-test comparisons were performed: non-Hispanic black versus non-Hispanic white, Mexican American versus non-Hispanic white, and female versus male.

^ⁱ

p-value less than 0.05;

^{^j}

p-value less than 0.01;

^{^k}

p-value less than 0.001.