The TRAIL Study: Tracking Radon exposure, Attention abilities, and Immune function Longitudinally - Abstract The public at large has grown keenly aware of the detrimental effects of environmental toxins on children’s neurocognitive development. Still, one surprisingly common, but rarely studied environmental toxin is radon. Radon is a naturally occurring radioactive gas that accumulates in homes and poses significant health risks, including increased risk of developing certain cancers and neurodegenerative diseases. The United States Environmental Protection Agency set the action limit for home radon concentrations at 4 pCi/L, which is the carcinogenic equivalent of smoking 10 cigarettes per day. An astonishing 1 in 15 homes across the country is expected to have radon levels at or above the action limit, leaving a large number of youth chronically exposed to high levels of radon. Groundbreaking work from our group demonstrated for the first time that home radon exposure is linked with altered functional brain activity serving attention in youth, with the most extreme examples suggesting as much as a seven-year delay in expected neurodevelopment. Notably, these aberrations scale with neurobehavioral symptoms like hyperactivity. We also showed that radon exposure is associated with robust increases in biomarkers of inflammation, suggesting an important biological mechanism through which radon may imbue neurotoxic effects. Still, studies linking radon toxicity to altered neural and cognitive development are extremely sparse, and we do not yet know the degree to which these radon-related aberrations in brain, behavior, and immune function persist over time during the course of an individual’s development. The current proposal aims to address this critical gap in knowledge by examining the impact of home radon exposure on immune functioning, neural circuitry, and behavioral wellness longitudinally across a period of heightened neurodevelopmental sensitivity, and thus heightened vulnerability. To this end, we will recruit a large cohort of youth ages 8-11 years-old at the time of enrollment, and follow them across three study time points set 18 months apart. Thus, the final evaluable data will span ages 8-14 years, effectively capturing a period of robust attention network maturation in the brain. At each time point, youth in this multimodal neuroimaging study will undergo magnetoencephalography (MEG) during a battery of tasks designed to assess neural systems serving attention. Youth will also undergo high-resolution structural MRI scans, complete assessments that richly profile attention abilities, and provide blood samples to measure inflammation. Families will also complete multiple home radon tests to accurately assess home radon levels. We will pursue the following Aims: 1) map the longitudinal trajectories of attention network development in youth experiencing various levels of radon exposure, 2) identify the links between these patterns of brain function and behavioral outcomes, and 3) quantify the potential mediating effects of inflammation on these environment-brain-behavior relationships over time. The outcomes of this study have the potential to shape the future of public health policy surrounding radon awareness and mitigation efforts, and this is especially true in the local region where home radon levels are some of the highest in the nation.
