Air pollution tops Google search lists as people fear for health, issue a year-round problem

Data from Google shows that smog and pollution-related updates topped the search list trends across several cities at the start of the day, as Indians grow increasingly concerned about air pollution and related health issues.

The concern tops other health problems such as heart attacks and the flu, as air pollution-related search terms peak in October-November, with interest from the Delhi-National Capital Region driving the most traffic.

The period sees industrial activity combined with crop burning exercises and high winds envelop much of north India in visibly toxic smog. And though interest in air pollution peaks at this time of the year, it is in fact a year-long, nationwide phenomenon.

There are many ways to measure air pollution and, on almost all of these measures, India’s air is more dangerous than the global average. On PM2.5 levels, which measures the concentration of the smallest and most dangerous pollutants in the air, the country’s air is especially toxic.

For instance, in 2016, the last year for which there is globally comparable PM2.5 data, the average population-weighted exposure to PM2.5 in India was 76 micrograms per cubic metre (mg/m3). This is around 50 percent higher than the global figure of 50, eight times higher than the World Health Organization’s (WHO’s) recommendation of 10 mg/m3, and nearly double the less stringent Indian government recommendation of 40 mg/m3.

PM2.5 is especially dangerous because it can travel far from its source, making it a nationwide problem affecting both cities and villages. India’s air monitoring stations, though, only capture air quality in cities.

This risks making air pollution an urban problem when it is equally a rural one. According to one estimate, PM2.5 levels were actually 2 percent higher in rural India compared to urban areas in 2015.

Even among cities, much of the discourse has focused on the air quality in major cities—and notably Delhi—when almost all Indian cities are breathing bad air. Between 2017 and 2018, PM2.5 levels increased in 21 of the 26 cities for which data was available.

In 2018, Delhi, Agra and Lucknow were cities with the foulest air. And, only six cities had air that met the Indian benchmark of 40 mg/m3.

Breathing in dirty air not just hurts the lungs, but can have other, equally damaging effects. PM2.5 particles, for instance, are associated with a range of other deadly diseases including strokes and heart attacks. These threats are prematurely curtailing lives around the world and in India.

According to the Air Quality Life Index, an index converting air pollution concentrations into their impact on life expectancy, calculated by researchers from the University of Chicago, the average Indian’s life expectancy would increase by around four years if PM2.5 levels were brought down to WHO standards.

In the polluted northern belt of the country, the rewards would be even larger with life expectancy potentially increasing by seven years.

Beyond health costs, air pollution can also hurt the economy in other ways. In a 2018 study, Jamie Hansen-Lewis of Brown University finds that air pollution hurts productivity in India’s labour-intensive industries.

She estimates that bringing the country’s air to global standards would lead to a small increase in profits of 0.3 percent across manufacturing companies with more pronounced effects in labour-intensive firms.

Similarly, pollution is also hurting agriculture by stifling crop productivity. One 2014 study estimated that air pollutants were responsible for 19 percent of the loss in yields in wheat production in India in 2010.

Finally, air pollution is also linked inextricably to climate change. Some of the same particles that clog up the lungs can clog up the atmosphere and contribute to the changing weather patterns.

If the effects of air pollution are manifold, so are the causes. Globally, air pollution is largely a product of five factors: Vehicles, industry, household burning (wood/coal), natural sources (for example, dust or sea salt) and other human activity (for example, crop burning).

In India, too, all these factors matter, but their relative importance changes with geography. In many parts of India, for instance, the biggest source of PM2.5 in outdoor air actually comes from indoors. Millions of Indians still use traditional cooking methods that generate fumes laden with PM2.5.

In larger metros, where clean cooking fuels are more prevalent, pollution sources vary more. For instance, according to UrbanEmissions.info, an air pollution data portal, Delhi’s pollution, especially in the October-December period, is a combination of vehicles (around 30 percent of PM2.5 emissions), industry (20 percent) and crop burning (15 percent). In Chennai, air pollution is driven more by industrial activity (around 70 percent of emissions).

Different sources of air pollution require different policies that address these sources. And, given that air pollution has no boundaries, policies cannot be city-centric and should instead focus on regions, according to Santosh Harish, a fellow at the Delhi-based Centre for Policy Research.