Home interventions are effective at decreasing indoor nitrogen dioxide concentrations

Abstract

Nitrogen dioxide (NO2), a by-product of combustion produced by indoor gas appliances such as cooking stoves, is associated with respiratory symptoms in those with obstructive airways disease. We conducted a three-armed randomized trial to evaluate the efficacy of interventions aimed at reducing indoor NO2 concentrations in homes with unvented gas stoves: (i) replacement of existing gas stove with electric stove; (ii) installation of ventilation hood over existing gas stove; and (iii) placement of air purifiers with high-efficiency particulate air (HEPA) and carbon filters. Home inspection and NO2 monitoring were conducted at 1 week pre-intervention and at 1 week and 3 months post-intervention. Stove replacement resulted in a 51% and 42% decrease in median NO2 concentration at 3 months of follow-up in the kitchen and bedroom, respectively (P = 0.01, P = 0.01); air purifier placement resulted in an immediate decrease in median NO2 concentration in the kitchen (27%, P < 0.01) and bedroom (22%, P = 0.02), but at 3 months, a significant reduction was seen only in the kitchen (20%, P = 0.05). NO2 concentrations in the kitchen and bedroom did not significantly change following ventilation hood installation. Replacing unvented gas stoves with electric stoves or placement of air purifiers with HEPA and carbon filters can decrease indoor NO2 concentrations in urban homes.

24-h Nitrogen dioxide concentration is associated with cooking behaviors and an increase in rescue medication use in children with asthma

“…In a prior study, we found that week-long NO 2 concentrations in home with gas cooking appliances decreased following replacement of the gas stove with an electric stove and with installation of a HEPA and carbon filter. [33] However, replacement of a stove may not be a feasible solution for all homes, and previous research suggests that compliance with continuous use of an air purifier is relatively low, with air purifiers being used on only about 60% of days in a randomized trial of air cleaners. [34] Thus, targeted use of air purifiers or ventilation hoods during periods of use of combustion sources that contribute to short-term increases in NO 2 concentrations may be associated with higher compliance, be more cost-effective, and therefore more feasible.…”

The Effects of Air Pollution and Temperature on COPD

“…Furthermore, defining the harmful impact of indoor air quality on COPD morbidity is of utmost importance as indoor air pollution is a highly modifiable exposure. Feasible interventions that improve in-home air quality (111–113) and optimize indoor temperature (114) may represent cost-effective and novel therapeutic arenas for a disease with limited treatment options.…”

Indoor Environmental Control Practices and Asthma Management

“…One randomized controlled trial found reductions of 40% to 50% in indoor NO 2 concentrations when a gas stove was replaced with an electric one. 74 Whether this degree of indoor NO 2 reduction results in improvements in asthma remains unclear, however.…”