. 2015 Apr 23;12(5):4481–4501. doi: 10.3390/ijerph120504481

Table 4.

Univariable association of cord blood metal concentrations with mother’s individual and household characteristics as potential confounding variables based on data from n = 100 newborns.

Variables	Category	N	Lead		Mercury		Aluminum		Manganese
Variables	Category	N	Mean ^a (SD) ^b	p	Mean ^a (SD) ^b	p	Mean ^a (SD) ^b	p	Mean (SD)	p
Maternal age (years) (at newborn’s birth)	<30	55	0.6 (2.6)	0.53	3.7 (1.9)	0.22	8.4 (3.3)	0.27	44.0 (24.3)	0.83
Maternal age (years) (at newborn’s birth)	≥30	45	0.7 (2.4)	0.53	4.2 (2.1)	0.22	7.0 (3.7)	0.27	43.2 (26.9)	0.83
Maternal education (at newborn’s birth)	Up to high school	30	0.6 (3.2)	0.88	3.7 (2.4)	0.35	12.2 (4.5)	<0.01	42.8 (32.9)	0.74
Maternal education (at newborn’s birth)	Beyond high school	70	0.6 (2.1)	0.88	4.1 (1.8)	0.35	6.4 (2.7)	<0.01	44.1 (21.5)	0.74
Previous pregnancies ^c	Yes	57	0.6 (2.4)	0.51	3.9 (1.9)	0.55	8.0 (3.2)	0.81	43.0 (24.2)	0.56
Previous pregnancies ^c	No	38	0.6 (2.8)	0.51	4.1 (2.4)	0.55	7.7 (4.1)	0.81	45.2 (29.7)	0.56
Car ownership	No	49	0.6 (2.5)	0.73	3.8 (2.0)	0.30	9.3 (3.4)	0.03	46.0 (25.5)	0.21
Car ownership	Yes	51	0.6 (2.4)	0.73	4.1 (2.0)	0.30	6.4 (3.3)	0.03	41.5 (25.0)	0.21

^a Mean lead, mercury, and aluminum indicates the geometric mean = Exp. [Mean (ln of metal concentration)] ^b SD of lead, mercury, and aluminum indicates the geometric standard deviation = Exp. [standard deviation of (ln of metal concentration)] ^c Previous pregnancies is missing for 5 mothers.