Personal NO(2) Sensor Demonstrates Feasibility of In-Home Exposure Measurements for Pediatric Asthma Research and Management

BACKGROUND: One of the most common pollutants in residences due to gas appliances, NO(2) has been shown to increase the risk of asthma attacks after small increases in short term exposure. However, standard environmental sampling methods taken at the regional level overlook chronic intermittent exposure due to lack of temporal and spatial granularity. Further, the EPA and WHO do not currently provide exposure recommendations to at-risk populations. AIMS: A pilot study with pediatric asthma patients was conducted to investigate potential deployment challenges as well as benefits of home-based NO(2) sensors and, when combined with a subject’s hospital records and self-reported symptoms, the richness of data available for larger-scale epidemiological studies. METHODS: We developed a compact personal NO(2) sensor with one minute temporal resolution and sensitivity down to 15ppb to monitor exposure levels in the home. Patient hospital records were collected along with self-reported symptom diaries, and two example hypotheses were created to further demonstrate how data of this detail may enable study of the impact of NO(2) in this sensitive population. RESULTS: 17 patients (55%) had at least one hour each day with average NO(2) exposure > 21ppb. Frequency of acute NO(2) exposure >21ppb was higher in the group with gas stoves (U=27, p≤0.001), and showed a positive correlation (r(s)=0.662, p=0.037, 95% CI 0.36–0.84) with hospital admissions. SIGNIFICANCE: Similar studies are needed to evaluate the true impact of NO(2) in the home environment on at-risk populations, and to provide further data to regulatory bodies when developing updated recommendations.