Not just outdoor, indoor air in Delhi polluted too: Study

Staying indoors to avoid toxic outdoor air in the national capital may not serve the purpose anymore as pollutants have now entered homes.

A new study has revealed that air inside homes in Delhi have become unsafe with high levels of pollutants found in it, despite keeping doors shut.

"Houses in the city have very polluted air infested with large concentrations of PM2.5, carbon dioxide and harmful gases, with long-term health implications," said a study conducted by BreatheEasy Consultants with real-time monitoring of air quality inside more than 400 homes in Delhi-NCR spread across 200 large and small residential colonies.

The study was conducted between April 2018 and March 2019 by BreatheEasy Consultants, indoor air quality experts.

The study claims that it assessed air quality inside various types of homes with respect to three air-borne pollutants -- particulate matter 2.5, Carbon Dioxide (CO2), and Total Volatile Organic Compounds (TVOCs) -- that are emitted as gases from certain solids and liquids inside homes.

"The level of carbon dioxide inside many homes was found to be as high as 3,900 parts per million (ppm) against the recommended safe limit of 750 ppm, and TVOC concentration exceeded 1,000 g/m3 (micrograms per cubic meter air) in some cases, in contrast to the safe limit of 200 g/m3," the study said.

It said that even in situations where air purifiers were used, PM2.5 levels were above the safe limit as defined by the standard and CO2 and TVOC levels were many times higher than the permissible limits.

Barun Aggarwal, CEO, BreatheEasy Consultants, said, "Most people can recognise the health concerns associated with outdoor air pollution, but they rarely consider how poor their indoor air quality is, even though an average human spends nearly 80-90 per cent of their time indoors."