Impact of early adolescent lead exposure on brain function and response: Findings from a Chinese cohort

Purpose

While the detrimental effects of lead exposure on cognition have been well documented, less research has focused on pre-adolescent populations. The purpose of this study was to understand the relationship between adolescent lead exposure and measures of brain functionality.

Methods

In a Chinese early adolescent cohort (N = 258 (50.1 % female) mean age 11.51 years) we examined associations between blood lead levels (BLLs) and P300 event-related potential elicited by three types of stimuli during an auditory oddball task.

Results

Mean BLLs in adolescence were 3.17 mcg/dl. In ANOVAs comparing BLL groups above and below the mean, those with greater BLLs had significantly prolonged novelty P300 latency (F=4.67; p = 0.032). In linear models adjusted for age, sex, BLLs at 3–5 years, child IQ, residence location, parent's education, and father’s smoking during pregnancy, increasing BLLs were associated with a 20.21 ms increase in target latency (95 % CI 3.73, 36.69). In sex stratified analyses, a 1 mcg/dl increase in BLLs was associated with a 26.64 ms increase in novel latency in males only (95 % CI 3.49, 49.78).

Discussion

Our results suggest a modest association between early adolescent lead exposure and detriments in neurophysiology, particularly related to novelty P300 in males and target P300 in the overall sample. Future research can consider how P300 alterations influence child and adolescent developmental trajectories and test ERP measures as a mediator between early life environmental exposures and later health decision making.