Appendix 1:

Regression model results for the main effect of MeHg exposure when endpoints were either log10 transformed or untransformed.

Outcome	n	Slope	SE	Lower	Upper	p-value
log10, BNT total	375	0.000	0.002	−0.004	0.005	0.95
CBCL total	369	−0.608	0.560	−1.710	0.494	0.28
CELF-5 total	369	0.651	0.381	−0.099	1.401	0.09
CELF-5 FD	376	0.186	0.100	−0.010	0.382	0.06
CELF-5 LC	376	0.124	0.065	−0.004	0.253	0.06
CELF-5 RS	374	0.170	0.179	−0.183	0.522	0.35
CELF-5 SC	372	0.117	0.098	−0.075	0.309	0.23
CELF-5 USP	374	0.027	0.080	−0.130	0.185	0.73
FT dominant hand	376	−0.084	0.117	−0.315	0.146	0.47
FT non-dominant hand	376	−0.005	0.108	−0.217	0.207	0.96
KBIT-2 word knowledge	376	0.204	0.191	−0.172	0.580	0.29
KBIT-2 matrices	376	0.178	0.121	−0.061	0.416	0.14
SCQ total	369	−0.042	0.101	−0.241	0.157	0.68
SRS total	375	0.068	0.407	−0.733	0.868	0.87
log10, trailmaking time A	337	0.003	0.005	−0.006	0.012	0.46
log10, WJ-III applied problems	375	0.002	0.002	−0.001	0.006	0.20
WJ-III letter word	374	0.942	0.545	−0.129	2.014	0.08

Note: n = sample size, slope = regression coefficient for MeHg, SE = standard error of slope, Lower = 2.5% lower confidence bound for slope, Upper = 97.5% upper confidence bound for slope. All outcomes were regressed on child’s 7 year hair MeHg (ppm) and the following covariates: mother’s age at delivery, maternal KBIT-2 matrices, prenatal MeHg from maternal hair at delivery (ppm), n-6:n-3 ratio, child’s age at 7 year testing, child sex (female = 1), family status at 7 years (both parents with child = 1), Hollingshead SES at 7 years.