Chronic radon exposure is associated with developmental alterations to neural and behavioral indices of cognitive...

Radon is a prevalent, naturally occurring gas which contributes to radiation within the environment and is the second-leading cause of lung cancer worldwide. Although many environmental toxins have been linked to maladaptive neurodevelopmental outcomes in children and adolescents, radon has seldom been examined for its effects on the developing brain. This study aimed to investigate the effects of chronic home radon exposure on top-down neural processes of cognitive control in youths. Fifty-nine participants (aged 6-14 years) completed a Simon interference task during magnetoencephalography (MEG), and radon levels were measured in their homes. MEG data were transformed into time-frequency space and significant oscillatory responses relative to baseline were imaged condition-wise and then subtracted to isolate the Simon interference effect (i.e., Simon-control). Whole-brain linear regressions indicated that children with greater radon exposure exhibited aberrant oscillatory activity in widespread networks related to attentional control. We also found that radon exposure moderated the developmental trajectory of theta and gamma oscillations underlying selective attention in frontoparietal cortices and other regions. Further, mediation analyses showed that the neural interference effects within cerebellar and extended motor cortices mediated the relationship between radon exposure and behavioral outcomes. Additionally, we found the mediating effects of neural interference within the left superior frontal gyrus and precuneus on the relationship between age and task accuracy were dependent on radon exposure. These data are among the first to demonstrate radon-related disruptions to the normative development of the neural substrates supporting cognitive control processes. Further, these disruptions have direct implications on observable behavior.