. Author manuscript; available in PMC: 2014 Jun 19.

Published in final edited form as: Neurotoxicology. 2011 Mar 29;32(4):450–457. doi: 10.1016/j.neuro.2011.03.009

Table 2.

Associations between WISC-4 raw scores and measures of arsenic and manganese exposure, before and after adjustment (N=299)

	Full Scale b (se)	Verbal Comprehension b (se)	Working Memory b (se)	Perceptual Reasoning b (se)	Processing Speed b (se)
*Adjusted only for the other metal*
Blood As	−6.11 (2.93)^*	−1.98 (0.82)^*	−1.35 (0.57)^*	−1.60 (1.05)	−1.18 (1.20)
Blood Mn	−18.52 (7.44)^*	−3.77 (2.10)⁺	−3.84 (1.44)^**	−7.68 (2.67)^**	−3.23 (3.04)
R²	4.0%	3.4%	4.7%	3.9%	0.8%
*Adjusted for other contributors*
Maternal intelligence	0.59 (0.14)^****	0.17 (0.04)^***	0.15 (0.03)^****	0.15 (0.06)^**	0.13 (0.06)^*
Maternal age	0.07 (0.23)	0.16 (0.07)^*	−0.02 (0.05)	0.04 (0.09)	−0.11 (0.10)
School months	1.01 (0.09)^****	0.21 (0.03)^****	0.14 (0.02)^****	0.24 (0.04)^****	0.42(0.04)^****
Head circumference	3.28 (0.96)^***	0.73 (0.31)^*	0.64 (0.21)^**	1.62 (0.40)^****	0.31(0.43)
Plasma ferritin
High (>32.5) vs. low	5.55 (2.76)^*	1.39 (0.89)	0.38 (0.60)	2.44 (1.14)^*	1.33 (1.24)^*
Not available vs. low	6.05 (6.85)	1.02 (2.21)	0.66 (1.48)	−0.19 (2.84)	4.55 (3.07)
Blood As	−3.80 (2.20)⁺	−1.49 (0.71)^*	−0.91(0.47)⁺	−1.13 (0.91)	−0.27 (0.99)
Blood Mn	−9.69 (5.65)⁺	−1.69 (1.82)	−2.56 (1.22)^*	−4.88 (2.34)^*	−0.56 (2.53)
R²	47.9%	31.2%	35.8%	30.8%	35.5%

Note: values for Blood As and Blood Mn have been log-transformed.

⁺

0.05<p<0.09

p<0.05

^**

p<0.01

^***

p<0.001

^****

p<0.0001