Household-level interventions for air pollution ,such as Hepa filters and electrostatic air filters, contributed to a reduction of 41.6 per cent in acute asthma attacks, a study by doctors and researchers at the All India Institute of Medical Sciences (AIIMS) and Indian Institute of Technology (IIT) Delhi has found.
Dr Harshal Ramesh Salve, additional professor, Centre for Community Medicine at the AIIMS, and a team of researchers from IIT Delhi conducted the study on household-level interventions, alternative transport strategies and vehicle rationing.
The study was conducted under a project to tackle air pollution in Delhi-NCR by the office of scientific adviser to the government of India.
Community-based interventions reduced all-cause mortality by 6 to 11 per cent, cardiovascular mortality by 11-17.9 per cent, respiratory mortality by 22-22.8 per cent and infant mortality rate by 20 per cent, the study found.
The study also found that there was an increase in FEV1 (forced expiratory volume) by 4.4 per cent due to these interventions. It is a measurement taken from a pulmonary function test to calculate the amount of air that a person can force out of their lungs in one second. The per cent change in microvascular and lung function was around 1.4 per cent and 0.8 per cent, the study said.
Of the 25 studies, seven were on community-based interventions, including alternative transport strategies, vehicle rationing, diesel ordinance scheme, opening of bypass roads, congestion charging scheme on vehicles and industrial interventions such as two control zone policy and regional regulatory law implementation.
18 of the studies were on air purifiers and electric heater use such as Hepa filters, electrostatic air filters, ionisation air purifiers, electric heaters, cook stove use such as eco-stove, improved biomass stove, rocket mud stove implementation and improved wood cookstove.
According to Dr Salve, there is a need to document the evidence more robustly. He said that the responsibility lies with the scientific community to provide evidence on air purifiers and with the government when it comes to advocacy for using these. “This is because there is no robust evidence to justify its use. So we need to move in that direction,” he added.
“There there is a need to give more information to the public on its cost-effectiveness. There should also be communication on how to use air purifiers; whether it has to be used in a closed environment, whether gross ventilation should be there and about its maintenance, the cost and everything. So our emphasis should be there on giving proper communication to the general public about the use of air purifiers,” he said.