Table 2.

Epidemiology studies reporting associations between postnatal MeHg exposure and developmental endpoints

Reference	Postnatal index	N	Age of testing	Tests Associated with Postnatal exposure measured in child hair
Grandjean et al., 1995	Hair Hg 1 y	581	1 yr	Beneficial association with Developmental milestones (sitting, creeping, standing):
Grandjean et al., 1997	Hair Hg 1 and 7 y	917	7 yr	Child’s hair at 1 year “…was a significant predictor for Finger Tapping with both hands and CPT reaction time…” Child’s hair at 7 years “…was significantly associated with CPT reaction time, Block Designs, and Bender Visual Motor Gestalt errors.” However, “…after adjustment for the cord blood mercury concentration, the hair mercury measures were not significantly related to any dysfunction.”
Grandjean et al., 1999a	Hair Hg 7 y Blood Hg	903	7 yr	Bender Gestalt: significant adverse association with both biomarkers
Debes et al., 2006	Hair Hg 14 y	878	14 yr	“Postnatal methylmercury exposure had no discernible effect.”
Cordier et al. 2002	Hair Hg 0.5–6 y	378	0.5–6 y	Child hair Hg associated with bead memory score and digit span score in girls only
Grandjean et al., 1999b	Hair Hg 7–12 y	351	7–12 y	“Neuropsychological tests of motor function, attention, and visuospatial performance showed decrements associated with the [child] hair-mercury concentrations.”
Murata et al. 1999	Hair Hg 7 y	149	7 y	“No…relationships were seen with the child’s own hair-mercury concentration…”
Davidson et al., 1998	Hair Hg 5.5 y	711	5.5 yr	Bender-Gestalt: THg by Sex interaction significant. Males significantly worse as exposure increases PLS: No interaction. Significant improvement with increasing exposure W-J Applied Problems: No interaction. Significant improvement with increasing exposure
Myers et al., 2000	Hair Hg 5.5 y	711	5.5 yr	CBCL: No significant associations with subscales
Axtell et al., 2000	Hair Hg 5.5 y	711	5.5 yr	MSCD GCI: Nonlinear models showed an association. Scores improved below 10 ppm and worsened above 10 ppm
Huang et al., 2003	Hair Hg 5.5 y	711	5.5 y	MSCD-GCI, W-J subtests, and Bender Gestalt only for females: using measurement error models a beneficial association present
Myers et al., 2004	Hair Hg 9 y	643	9 y	CBCL - Thought Problems subscale: An adverse association

CBCL = Child Behavior Checklist

MSCD = McCarthy Scales of Child Development

CPT = Connor’s Continuous Performance Test

Hg = mercury

W-J = Woodcock-Johnson

PLS = Preschool Language Scale

GCI = General Cognitive Index

THg = Total mercury