Personal NO2 sensor demonstrates feasibility of in-home exposure measurements for pediatric asthma research and management.

Abstract

BackgroundOne of the most common pollutants in residences due to gas appliances, NO2 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.AimsA pilot study with pediatric asthma patients was conducted to investigate potential deployment challenges as well as benefits of home-based NO2 sensors and, when combined with a subject’s hospital records and self-reported symptoms, the richness of data available for larger-scale epidemiological studies.MethodsWe developed a compact personal NO2 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 NO2 in this sensitive population.Results17 patients (55%) had at least one hour each day with average NO2 exposure > 21ppb. Frequency of acute NO2 exposure >21ppb was higher in the group with gas stoves (U=27, p≤0.001), and showed a positive correlation (rs=0.662, p=0.037, 95% CI 0.36–0.84) with hospital admissions.SignificanceSimilar studies are needed to evaluate the true impact of NO2 in the home environment on at-risk populations, and to provide further data to regulatory bodies when developing updated recommendations.