Regardless of income, all Delhi homes breathing poor air: Study

In households, both in the high and low socio-economic strata, PM2.5 levels were 20 times more than the World Health Organisation (WHO) standards, noted the study by Michael Greenstone, Kenneth Lee and Harshil Sahai.

The average indoor PM2.5 level was 229 µg/m3 for households in the low socio-economic strata and 289 µg/m3 for the high-income ones. The WHO standard is 10 µg/m3 annually, while the country’s standard is 40 µg/m3.

Although the average figure is lower in low SES households, after controlling for other factors including outdoor particulate matter, time of day and the day of the week, the low SES sample was found to have higher indoor particulate matter levels. After controlling these other factors, the study arrived at the conclusion that indoor PM2.5 levels were 10% higher for low SES households.

According to a communication issued by the institute, the lead author of the study, Kenneth Lee, said, “In Delhi, the bottom line is — whether someone is rich or poor, no one gets to breathe clean air.”

He further said, “It’s a complex vicious cycle. 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. Only with increased awareness, demand for clean air may gain momentum.”

Around 1.8% of the low SES households owned air purifiers. This figure rises to 4.9% for the medium and high SES households, and 24.1% for high SES households.

The low SES households mostly belong to JJ clusters in the city, and they were surveyed between October 2018 and March 2019.

The medium and high SES households were surveyed between 2019 and 2020.

A total of 3,002 households falling in the low SES category were part of the study, while 703 were from the medium and high SES, and 55 were in the high category.

To identify medium and high SES households, the researchers partnered with resident welfare associations.

A total of 96.5% of respondents among the low SES households use LPG as the primary cooking fuel, while 100% of the medium and high SES households said they use LPG as their cooking fuel, the data from the study suggested.