Even if he hadn’t set foot outside his clinic in Mumbai, consultant respirologist Dr Lancelot Pinto would have known from his patients’ laboured breathing that something was wrong with the city’s air.
“A significant proportion of patients over the past month have had respiratory symptoms that were of an irritant or allergic nature,” says Pinto. Some had complained “of chest tightness, cough, wheezing when outdoors”. Infection was less likely to have triggered this, Pinto reasons, than Mumbai’s suddenly bad air.
India’s capital New Delhi captures global attention for the toxic air that engulfs its unfortunate inhabitants every winter: farmers burn stubble in nearby provinces and smoke clouds the inland city.
But for a few weeks in November and December, the coastal commercial centre of Mumbai, usually spared such smog, recorded worse air pollution levels than New Delhi several times. According to air quality monitor AQI, Mumbai was India’s third worst-performing metropolis over the four weeks to December 19, behind New Delhi and Kolkata in the east.
“South Asia suffers from extreme air pollution,” according to a World Bank report this month. It says nearly 60 per cent of the region’s population breathes in air whose concentration of tiny dust or soot particles is seven times over WHO guidelines. It estimates air pollution in South Asia causes the premature death of 2mn people a year.
Air pollution is even a significant motivation for rich Indians to leave the country, thinks Ajay Sharma, founder of the consultancy Abhinav Immigration. They say: “What use is our wealth when we lose years of our life living in Delhi?” But denizens of Mumbai, home to India’s biggest slum, Bollywood stars and India’s second-richest man Mukesh Ambani, do not usually need to worry.
“It is seen as, oh Mumbai is on the coast so there’s a sea breeze coming and blowing all the pollution away,” explains Anumita Roy Chowdhury, research and advocacy director at the Centre for Science and Environment. “It breeds a sense of complacency — people begin to think that it is only northern India which has the problem, and they are safe.”
“Somehow we have to break that myth,” she adds. She says “the health science is showing very clearly” that people fall ill and die at pollution levels seen in cities such as Mumbai, Chennai and Bangalore in India’s western and southern states.
As Mumbaikars could barely see from one end to the other of the iconic 5.6km Sea Link bridge, the cause of the haze was just as unclear. Meteorologists watching included Dr Gufran Beig, founder and project director of India’s air quality forecasting system known as Safar. His air- monitoring data illustrated the severity of the pollution spike: between November 5 and December 12, Mumbai’s air quality index recorded a “poor” reading for 20 days, compared with six days in the same period in 2021. Four days were “very poor”, against zero last year.
Beig says this winter, “surface wind speeds were relatively much slower than the last 10 years average”. Nor were winds changing direction and bringing sea air every few days as they usually do; the self-cleaning system had broken down. “The much-needed wind from ocean to land was only triggered last week,” he explained before Christmas. Without a breeze to sweep them away, the high emissions — from vehicles, waste burning, industry, construction dust — became trapped in an eye-stinging haze.
This unusual circulation is part of a broader derangement in wind patterns due to a prolonged La Nina weather effect over India, which is linked to climate change, says Beig.
India now has the G20 presidency, and on December 14, delegates of the body’s development working group landed in a Mumbai primped for their arrival — fresh paint on the walls, curtains and banners obscuring slums on their route, a lavish dance and music show laid on close to the Gateway of India monument. Miraculously, it was the clearest day in weeks.
Mumbai updated its clean air plan in 2019. But that’s not enough. Experts say officials must now implement it, before the wind changes.