Delhi, the capital of India, has an alarmingly high level of indoor air pollution, shows new research.
The research found that the levels of lung-damaging tiny particles (PM2.5) in the air were substantially higher indoors than those found on the nearest outdoor government monitors.
The research was done by the Energy Policy Institute at the University of Chicago (EPIC), between 2018 and 2020.
Thousands of Delhi households across varying socio-economic backgrounds were surveyed and found that rich and poor households were equally affected.
It was reported that high-income households were 13 times more likely to own air purifiers than low-income households but that reduced the pollution by 10% only.
"In Delhi, the bottom line is - whether someone is rich or poor, no one gets to breathe clean air," said Dr Kenneth Lee, the lead author of the study.
The air pollution levels indoors can be two to five times higher than outdoors, says the Environmental Protection Agency (EPA).
This is especially concerning for India as it has the most air pollution in the world with 22 of the world's top 30 polluted cities.
The toxic air of India kills more than one million people every year.
However, people are averse to take defence measures despite Delhi routinely topping the list of "world's most polluted capitals", said the report.
Researchers observed that even when people were offered a free trial of indoor air quality monitor to track pollution levels inside their homes, the take-up rates were low.
"When you do not know about the pollution levels inside your homes, you do not worry about it, and hence you are less likely to take corrective actions," said Dr Lee.
The World Health Organization (WHO) estimates that globally about seven million people die prematurely each year from diseases linked to air pollution, which puts it on par with smoking and unhealthy eating.
"Official government data shows Delhi recorded its worst November air in at least six years, with residents not experiencing even one "good" day of air quality through the month. Schools were shut amid worsening pollution levels and the situation was so dire that it also prompted a stern warning from India's Supreme Court." Reports BBC.