Modeling the Impact of an Indoor Air Filter on Air Pollution Exposure Reduction and Associated Mortality in Urban Delhi Household

Indoor exposure to fine particulate matter (PM 2.5 ) is a prominent health concern. However, few studies have examined the effectiveness of long-term use of indoor air filters for reduction of PM 2.5 exposure and associated decrease in adverse health impacts in urban India. We conducted 20 simulations of yearlong personal exposure to PM 2.5 in urban Delhi using the National Institute of Standards and Technology’s CONTAM program (NIST, Gaithersburg, MD, USA). Simulation scenarios were developed to examine different air filter efficiencies, use schedules, and the influence of a smoker at home. We quantified associated mortality reductions with Household Air Pollution Intervention Tool (HAPIT, University of California, Berkeley, CA, USA). Without an air filter, we estimated an annual mean PM 2.5 personal exposure of 103 µg/m 3 (95% Confidence Interval (CI): 93, 112) and 137 µg/m 3 (95% CI: 125, 149) for households without and with a smoker, respectively. All day use of a high-efficiency particle air (HEPA) filter would reduce personal PM 2.5 exposure to 29 µg/m 3 and 30 µg/m 3 , respectively. The reduced personal PM 2.5 exposure from air filter use is associated with 8–37% reduction in mortality attributable to PM 2.5 pollution in Delhi. The findings of this study indicate that air filter may provide significant improvements in indoor air quality and result in health benefits.