EVERY YEAR, FOR ABOUT a decade now, as the monsoon retreats and winter approaches, a familiar story of high pollution and low visibility breaks out in Delhi. It happened again once more, when the city’s air quality, already deteriorating over the last few days, fell into the poor category, and even registered an AQI (air quality index) of 256 on October 26. But this time, something else was also happening. It wasn’t just Delhi waking up to poor skies, but Mumbai too. For several mornings in the last few weeks, the financial capital found itself covered in an unusual film of dust and near-invisible skies.
Mumbai in fact witnessed one of its worst Octobers in air pollution levels in recent memory, going beyond Delhi on several days, with some parts of the city even registering an AQI beyond that of 300. (Anything that is 200 or above is considered ‘poor’ air quality, while 300 and above signifies ‘very poor’ air.) Something like this change in Mumbai’s air quality was visible during the last winter too, when the city experienced an unusual and prolonged spell of poor air quality that stretched from late October to early February.
Of the two cities, the poor air quality in Mumbai is particularly surprising. It is not as though Mumbai produces any less pollution than the national capital does. Delhi may have the misfortune of being a landlocked region, where during winters, the morning mists trap particles at the ground level. But in Mumbai, geography has usually been its advantage. Located by the sea, the strong breeze from it acts as a kind of natural cleaning mechanism, blowing dust and other suspended particles away from the city. But that safety blanket, it appears, was removed this time, as it was last winter. According to meteorologists, last winter’s bad air quality could have been affected in part by the prolonged La Niña phenomenon last year, where the waters of the Pacific Ocean around the Equator become colder than usual. In Mumbai, winds usually alternate between moving from the land towards the sea and vice-versa, the cycle every three to four days during this time of the year. The La Niña phenomenon last year, it is claimed, disrupted this cycle of wind patterns. This time however, it is believed, the city’s unusually high temperature led to winds from nearby cooler areas, moving into the city, bringing with them the dust it collected from the many construction projects that are currently underway across Mumbai and its nearby districts.
Like Delhi and several other large Indian cities, Mumbai’s air quality has been rapidly declining for quite some time. The sea breeze actually helped mask it to an extent. One of the main factors being blamed for the poor AQI in Mumbai is the rapid increase in construction in the city. The city is currently going through a massive construction process
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These unusual meteorological conditions are only part of the story. Like Delhi and several other large Indian cities, Mumbai’s air quality has been rapidly declining for quite some time. The sea breeze actually helped mask it to an extent. One of the main factors being blamed for the poor AQI in Mumbai is the rapid increase in construction in the city. The city is currently going through a massive construction process. Several infrastructures are being built, from the Mumbai Metro to the Coastal Road project, and many old buildings are being torn down to construct high rises. But there are other problems too, from rising vehicular emissions to the burning of garbage. The city’s municipal body, the Brihanmumbai Municipal Corporation (BMC), has awoken to the situation, and has in the last few days announced a slew of measures. These range from issuing new guidelines to be followed at construction sites and a ban on the burning of garbage to deploying “clean up marshals” who would fine people found violating new norms, and the talk of setting up air purifiers and smog guns at various locations. The city’s guardian minister Deepak Kesarkar has claimed the air quality will improve within one or two months. But whether that will happen, or continue to remain so throughout the coming and next few winters is anyone’s guess. The BMC had come in for criticism for the poor AQI last winter too, and it had reacted by issuing guidelines back then as well, several of them around construction activities. But it was an open secret that nobody was really following it. Rajiv Mishra, the principal of the JJ College of Architecture, told Open a few months back, “Construction activity releases dust particles into the air. They [the BMC] should give permission [for such projects] in parts. Not allow everything to happen at the same time. Redevelopment is the only way of recycling a city. But you have to consider these aspects too.”
In Delhi, an unfavourable meteorological condition, mainly caused by a drop in temperature and slow winds allowing pollutants to accumulate, along with the bursting of firecrackers in some areas during Dussehra (even though there is a ban on bursting firecrackers), has brought the first signs of a poor winter ahead. These ingredients, along with paddy straw burning in neighbouring Punjab and local sources of pollution, push Delhi’s air quality to hazardous levels from November onwards nearly every year. And with the first signs of a deteriorating winter ahead, the city’s government has announced, like it has done in the past, a slew of measures. These measures will only get more dire as and when winter approaches and air quality worsens.
This issue of poor air quality isn’t just limited to these two cities. Several Indian cities now routinely figure among the most polluted cities in the world. We are also better aware now of the risks of exposure to poor air. Several studies in recent years have shown how unhealthy amounts of particulate matter are linked to increased vulnerability to various forms of cancer, cognitive disorders and stunted development in children. A Lancet paper last year estimated India lost 1.67 million people in 2019 to diseases caused by inhaling hazardous amounts of PM 2.5. A more recent Air Quality Life Index, prepared by the University of Chicago’s Energy Policy Institute, estimates that pollution by these fine particles reduces the average Indian’s life expectancy by more than five years.
Several cities now have plans to combat air pollution levels. But these are only looked at seriously, as was the case with Delhi or Mumbai, when the issue assumes emergency proportions. Cleaning our air will require long-term planning and bringing various sections of society together. Unless that happens, we will keep waking up to poor skies.