Researchers from All India Institute of Medical Sciences (AIIMS) and Indian Institute of Technology (IIT), Delhi, conducted a study on household-level interventions, alternative transport strategies and vehicle rationing. It was found that household-level interventions such as using HEPA filters, and electrostatic air filters have reduced the risk of acute asthma attacks by 41.6 per cent.
Due to these community-based interventions, an increase in FEV1 (Forced Expiratory Volume in 1 second) was observed, which was about 4.4 per cent. FEV1 is the amount of air exhaled (or pushed out of the lungs) forcefully in 1 second.
These studies were part of a project to tackle air pollution in Delhi. A total of 25 studies were conducted. 7 studies were on community-based interventions like alternate transport strategies, vehicle rationing, diesel ordinance scheme, congestion charging scheme on vehicles, the opening of bypass roads and industrial interventions (like two control zone policies and regional regulatory law implementation).
The rest 18 studies were on air purifiers and electric heater use, such as HEPA filters, electrostatic air filters, ionization air purifiers, electric heaters, and cook stove use.