The relation of lead neurotoxicity to the event-related potential P3b component in Inuit children from arctic Québec.

Publication Type:

Journal Article


Neurotoxicology, Volume 30, Issue 6, p.1070-7 (2009)


Acoustic Stimulation, Adolescent, Arctic Regions, Child, Child, Preschool, Electroencephalography, Electrooculography, Event-Related Potentials, P300, Female, Fetal Blood, Humans, Inuits, Lead, Lead Poisoning, Nervous System, Childhood, Longitudinal Studies, Male, Mass Spectrometry, Maternal-Fetal Exchange, Neuropsychological Tests, Photic Stimulation, Pregnancy, Quebec, Reaction Time, Retrospective Studies


<p>The event-related potential (ERP) P3b, a cognitive electrophysiological measure that has been linked to working memory processing in many experimental paradigms, was measured in Inuit children from Nunavik (Arctic Québec, Canada) to assess lead (Pb) neurotoxicity. Visual and auditory oddball paradigms were administered at 5 (N=27) and 11 (N=110) years of age, respectively, to elicit this ERP component. Pearson correlations and multiple regression analyses were performed to examine the associations between Pb levels and P3b parameters (peak latency and amplitude). Greater prenatal Pb exposure was related to a decrease in P3b amplitude at 5 years of age, and early childhood Pb exposure was associated with delayed P3b latency at 5 years. No significant association was observed at 11 years. These results, in line with those from previous neurobehavioral studies, suggest that Pb exposure affects cognitive processing in children even though the Pb levels measured in a large majority of our sample were below the threshold value for public health intervention used by federal agencies. This study strengthens the arguments for reducing sources of Pb exposure in Nunavik and for lowering the blood Pb concentrations considered "acceptable" in governmental policies.</p>

Financement / Soutien / Partenaires

logo FRQ-S logo ctrn logo fci logo cihr irsc logo nserc logo MESISentinelle nord