Asthma Control Before and After Changing Gas Stoves to Electric Stoves

Background Cooking on natural gas stoves is a major source of indoor nitrogen dioxide (NO 2 ) exposure and may contribute to asthma exacerbations. Objective To assess asthma control before and after changing gas stoves to electric stoves. Methods We replaced gas stoves with electric stoves in the homes of 85 individuals with poorly controlled asthma (Asthma Control Questionnaire [ACQ] score > 1.5) and determined changes in ACQ score from baseline (1-4 weeks before stove change) to follow-up (2-3 months after change). Changes in emergency room visits or hospitalizations for asthma, missed work or school days because of asthma, and NO 2 levels were also examined. Results ACQ score improved from 2.6 to 1.5 following the stove change (difference -1.1, 95% confidence interval [CI] -1.3 to -0.8). At baseline, 10 individuals (11.8%) had an emergency room visit or hospitalization in the past 4 weeks. At follow-up, 3 individuals (3.5%) had an emergency room visit or hospitalization in the past 4 weeks (absolute difference -8.2%, 95% CI -16.2% to -3.4%). There were also significant improvements in missed work or school days. Indoor NO 2 levels decreased from 21.0 to 6.3 ppb (change -14.7, 95% CI -20.8 to -8.7). Conclusion Asthma control appeared to improve in the follow-up period after electric stove installation compared to the baseline period with a gas stove. People with poorly controlled asthma may consider transitioning away from gas stoves depending on their resources and circumstances. A controlled clinical trial is needed to confirm these findings and to assess long-term outcomes. Clinical Trial Registration ISRCTN78763245