Indoor air pollution poses greater health risk than outdoor: Experts

Indoor air pollution is a bigger health risk than outdoor air pollution in India, and sometimes cities are cleaner than nearby villages where household pollution is higher, according to the country's two top policy experts. Addressing the India Clean Air Summit (ICAS) 2024, Principal Advisor, Ministry of Health and Family Welfare, Soumya Swaminathan said, "Studies done in Delhi have shown that women's average exposure to high levels of black carbon (women who are mostly at home) is as much as auto-rickshaw passengers going around outdoor exposed to the ambient air pollution in Delhi, resulting in high systolic blood pressure."

"Cities contribute less than 20 per cent to the overall state emissions, wherever they have been assessed, but household emissions predominate, ranging between 20 per cent and 40 per cent. Across the country, we are seeing is that sometimes cities are cleaner than the surrounding villages where household air pollution predominates," she said at the summit organised by think-tank Center for Study of Science, Technology and Policy.

This builds a strong case for expanding the scope of India's National Clean Air Programme (NCAP), which currently focuses on non-attainment cities.

Air pollution is a major threat to public health and contributes to a significant amount of morbidity as well as mortality.

Apart from PM2.5 and PM10, short-lived climate pollutants such as black carbon, methane, ozone, and hydrocarbons have the potential to harm the environment and warm the atmosphere even more than CO2. Black carbon can cause chronic respiratory illnesses, lung cancer, emphysema, pneumonia, asthma, heart disease, and low birthweight.

"In terms of reducing our life expectancy, globally, PM2.5 is contributing to about 2.3 years of life lost. Just below that is tobacco. In fact, there's so much attention on tobacco and global frameworks for control, but not the same level of attention has been paid to PM2.5 and certainly not the same level of commitments," Swaminathan said.

The impact of air pollution is not limited to public health but has a significant economic cost as well. Recently, the World Bank published a study highlighting that air pollution has resulted in a loss of around USD 8.1 trillion in 2019, which is 6.1 per cent of the global gross domestic product (GDP).

"We are always talking about air pollution as a problem but studies also show a strong economic case for action on clean air. There are significant positive consequences to investing in cleaning up the air in terms of the return on investments. We know air pollution is not just bad for our health, but it's also bad for agriculture, because it reduces the sunlight that's reaching the crops and it's bad for our economy or any country's economy as it deters people from coming and living or visiting those places," Swaminathan added.

Kalpana Balakrishnan, Director, WHO Collaborating Center for Occupational and Environmental Health, said that the main barrier to shifting to clean cooking fuels that can help reduce household air pollution levels is finance.

"If we give free LPG to women for two years, they are unlikely to shift back to biomass cooking even if you remove the subsidies," she said.

Through Pradhan Mantri Ujjwala Yojana (PMUY) launched in May 2016, more than 100 million households in India received LPG cylinders by the end of March 2023.

Studies shows over 50 per cent of the households that received new LPG cylinders under PMUY did not choose to refill it even once.

Around a third of the world's population - 2.4 billion people globally (including 500 million people in India) - still lack access to clean cooking solutions.

Although the Ministry of Petroleum and Natural Gas (MOPNG) claims that the country's household LPG "coverage" stands at 99.8 per cent, the National Family Health Survey conducted in 2019-21 (NFHS-5) shows that 41 per cent of the population still cooks on biomass.