Indoor Air Quality Study Shows Aircraft in Flight May Have Lowest... Indoor Air Quality Study Shows Aircraft in Flight May Have Lowest... Study shows aircraft cabins with the lowest levels of tiny aerosol particles. Wednesday, March 10, 2021 1546 If you’re looking for an indoor space with a low level of particulate air pollution, a commercial airliner flying at cruising altitude may be your best option. A newly reported study of air quality in indoor spaces such as stores, restaurants, offices, public transportation — and commercial jets — shows aircraft cabins with the lowest levels of tiny aerosol particles.