TABLE 7.

Chronic Hg Dose-Response Effects Among Boys and Girls With ACGG (Group A) or GTCA (Group B) COMT Haplotype

	Haplotype
	GCGGval-GCGGval (Group A)		ATCAmet-ATCAmet (Group B)
Measure	Beta (SE)	rpart (p)	Beta (SE)	rpart (p)
Boys
Attention/Concentration
Stroop Test: Color	−3.87 (7.11)	−.16 (.60)	−13.08 (6.39)	−.47 (.06)
WAIS–III–Spatial Span	.56 (1.29)	.13 (.87)	−4.89 (1.84)	−.57 (.02)
Visual-Spatial
WAIS-III–Digit Symbol	.80 (11.16)	.02 (.94)	−32.90 (10.25)	−.64 (.006)
WAIS-III–Symbol Search	−.30 (4.16)	−.02 (.94)	−16.70 (5.71)	−.60 (.01)

Note. Values in bold signify p ≤ .05 with increasing Hg exposure.