Radon Asthma Intervention Trial (ROME) - Project Summary/Abstract Asthma is the most common chronic disease of childhood in the United States, causes significant morbidity, and accounts for billions of dollars in health care utilization, despite aggressive measures to identify remediable causes. Radon is the most important natural source of human exposure to ionizing radiation. Rn toxicity is due to its decay products that emit alpha (α), beta (β), and gamma (γ) radiation that form ultrafine clusters that attach to airborne particles rendering particulate matter (PM) radioactive. Radon sourced primarily from the adherence of airborne radioactivity to particulate matter, is common in US homes due to the broad geologic presence of radon in the earth's crust. Inhaled radon it associated radioactive PM deposits in the airways and alveolar regions damaging nearby cells. Recent evidence from our lab and others has identified radon as a key contributor to asthma and chronic obstructive pulmonary disease morbidity and mortality beyond the known carcinogen effects. These adverse health effects are seen at levels below the current World Health Organization recommended exposure thresholds for radon mitigation. We have collaborated for over 15 years to investigate environmental hazards in schools and homes of children with chronic respiratory diseases. From these studies, we have generated preliminary data that demonstrate: i) indoor Rn is associated with asthma symptoms and airway inflammation in children and ii) it is well-established that radon mitigation systems significantly reduce radon by 90% and thereby reduce particle radioactivity. Although our data is promising, the impact of radon mitigation on improving health outcomes can only be answered in a clinical trial. The results of our study could impact clinical practice. Our overall hypothesis is that reduction of radon in homes will result in significant reduction of asthma symptoms and inflammation in children with asthma. We propose a 48 week randomized, sham controlled, radon mitigation intervention trial in 180 children with asthma who live in high and low radon geologic exposure areas to 1) determine the effect of radon mitigation in the primary living space on asthma symptoms, primarily, as well as lung function; and 2) determine whether radon mitigation will reduce established biomarkers of inflammation, specifically airway FENO and established inflammatory biomarkers (IL4,5,13, 6, and C-Reactive Protein (CRP)). This study is an unprecedented, high impact opportunity to test a personalized remediation strategy for a ubiquitous but novel harmful respiratory exposure. Determining the benefit of radon interventions offers a precise and personalized mitigation strategy to improve asthma morbidity. These findings will inform public health policy regarding the risks of residential radon exposure in children with chronic health conditions and thresholds for mitigation. It will allow us to identify health burdens resulting from real-life indoor exposures and associated health effects among vulnerable children with asthma. If successful, this will provide guidance on cost-effective, environmentally-friendly, and scalable technologies to improve indoor air quality to reduce disease burden in an area of significant unmet need in children with chronic airway inflammation and asthma.
