These findings compliment a breadth of literature reporting age-related alterations in attention- and high order cognition-related neural dynamics (e.g., Killanin et al. 2020, Taylor et al. 2021, 2020), suggesting that these oscillatory responses are robustly sensitive to developmental processes during childhood and adolescence.
The maturational sensitivity of the functional brain dynamics serving attentional processing is of great importance when considering that youths are regularly exposed to a wide array of environmental toxins that could impact these developmental trajectories (Bearer, 1995; Perera et al., 2006). A growing literature evidences a myriad of negative outcomes in the neurodevelopment of children connected to various exposures, ranging from lead and other toxic metals (Sanders et al., 2015; Silver et al., 2016) to inhaled air pollutants (Chiu et al., 2016; Peterson et al., 2015). For instance, studies have demonstrated a relationship between increased exposure to a broad range of toxins and increased risk for anxiety and mood disorders (Bornschein et al. 2006), ADHD (Myhre et al., 2018), and learning and neurocognitive disorders (Sanders et al., 2015). Even low level toxin exposure has been related to impaired cognitive functioning and lowered intelligence in youth, including decreased attention and memory functioning (Chiu et al., 2016; Liu and Lewis, 2014; Perera et al., 2006; Sanders et al., 2015). Despite this growing body of research detailing the neurocognitive impacts of environmental toxins on the developing brain, the effects of some of the most common household toxins have not yet been characterized, most notably radon.
Radon is a ubiquitous gas that forms from the decay of naturally occurring uranium (Clement et al., 2010; Darby et al., 2005; Kang et al., 2019; Vogeltanz-Holm and Schwartz, 2018), and it can accumulate to hazardous levels in homes (Laquatra and Laquatra, 2018; Riudavets et al., 2022; Sethi et al., 2012; Vogeltanz-Holm and Schwartz, 2018). In fact, 1 in 15 homes in the United States is estimated to have radon levels exceeding the action limit recommended by the Environmental Protection Agency, which is an indoor concentration equal to or greater than 4.0 pCi/L (United States Environmental Protection Agency, 2016). Further, in the state of Nebraska, more than half of radon tests have results above 4.0 pCi/L (NDHHS, 2024). Despite the guidance from the EPA and Department of Health and Human Services, the public's knowledge of radon and its hazardous effects is severely lacking. Past research has linked radon exposure to multiple health concerns, including lung cancer (Sethi et al., 2012; Vogeltanz-Holm and Schwartz, 2018) and neurodegenerative diseases in adulthood (Gómez-Anca and Barros-Dios, 2020; Zhang et al., 2022). Further, recent work in children demonstrated robust links between home radon exposure and increases in specific biomarkers of inflammation (Taylor et al., 2022) that are regularly associated with detriments to neurocognitive development in youths (Ehrlich et al., 2021; Loftis et al., 2020; Miller et al., 2009).
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In the present study, we investigated the impact of home radon exposure on the neural oscillatory dynamics serving attentional reorienting in typically developing children and adolescents. To measure the neural processing underlying attentional reorienting, youths completed a classic Posner paradigm during high-density MEG. Home radon test kits were used to measure indoor radon concentrations in the family home. We hypothesized that the effects of radon exposure would be most notable in the theta, alpha, and beta range given their known developmental sensitivity in this paradigm and other higher order cognitive tasks. We predicted that chronic home radon exposure would be related to aberrations in task performance and neural oscillations within attention networks, such that children with higher radon exposure would exhibit both behavioral and neural decrements in attentional reorienting. Further, given the known exceptional sensitivity of these developing networks to environmental toxins, we explored potential interactions between age and radon exposure to see whether radon may be modulating expected developmental trajectories of these neural dynamics.