Influences of perinatal dioxin load to visual motion and oddball stimuli examined with an EEG and MEG analysis.

Objective: With MEG and EEG the effect of perinatal dioxin load of 38 healthy 7- to 12-year-old children was studied to assess possible disturbances of visual development.

Methods: Latencies and amplitudes of the motion (N2 with subcomponents) and oddball responses (N200 and P3b) were analysed after age correction.

Results: With increasing load, latencies increased and the amplitudes of the oddball components tended to be reduced. The latency increase between the high- and low-loaded children was about 13 ms (P<0.004) and the oddball response showed an amplitude decrease of 12% (P=0.009).

Conclusions: It may be concluded that, during the end-80s/early-90s, exposure to background levels in industrialized regions seems to have resulted in small underdevelopment or damage to visual motion processing and visual cognition.

Significance: Since dioxin pollution by incinerators still exists in many regions in developing countries and also still, although at a smaller scale, in the industrialized world, perinatal loads of similar magnitude and possibly more as measured in this study may occur and as a consequence might affect the developing brain.