Table 3.

Relation of Pb exposure to P3b parameters (Pz)

	Pb levels in cord blood			Pb levels at 5 years			Pb levels at 11 years
	N	Pearson r	Standardized β	N	Pearson r	Standardized β	N	Pearson r	Standardized β
5 years
P3b latency	27	−0.25	−0.08	27	0.55**	0.37*	-	-	-
P3b amplitude	27	−0.38*	−0.38*	27	−0.04	−0.04	-	-	-
11 years
P3b latency	108	0.07	0.00	40	−0.03	−0.02	107	0.04	−0.01
P3b amplitude	108	−0.06	−0.04	40	−0.30†	−0.27†	107	−0.05	−0.03

Note. 5-year data were obtained from a visual oddball paradigm whereas 11-year data were obtained from an auditory oddball paradigm. Analyses were performed with log-transformed blood Pb concentrations. Covariables included in the models were: maternal non-verbal intelligence, breastfeeding status and Hg levels at testing time (P3b latency at 5 years), haemoglobin, PCB-153 levels and age at testing (P3b latency at 11 years), and socioeconomic status (P3b amplitude at 11 years).

^**p ≤ 0.01

^*p ≤ 0.05

^†p ≤ 0.10