A public health emergency has been declared by doctors in Delhi as air quality in the world’s most polluted capital city plunged to levels likened to smoking at least 50 cigarettes in a single day.
Slow winds and colder temperatures have been blamed for a surge in airborne pollutants beyond what instruments in the city could measure with some recording an Air Quality Index (AQI) maximum of 999.
The Indian Medical Association said the country’s capital was suffering a health emergency and called for an upcoming half-marathon to be cancelled to avoid “disastrous health consequences”.
Residents were warned to avoid leaving their homes as smog enveloped streets and landmarks on Tuesday, sparking road, rail and airport delays and renewed calls for Indian state and federal governments to act.
The Delhi chief minister, Arvind Kejriwal, said the city was a “gas chamber” as his government met on Tuesday afternoon to consider a response to the crisis. Primary schools, already asked to keep students indoors, will be shut on Wednesday and possibly longer if the poor conditions persist.
Most dangerous to health are concentrations of fine pollutants smaller than 2.5 micro-metres – tiny enough to evade the body’s natural filters and permeate the blood-brain barrier.
Tests by Greenpeace have shown these fine pollutants – called PM2.5 – can include carcinogenic chemicals such as lead, arsenic, cadmium and mercury. Levels of PM2.5 in Delhi on Tuesday reached 710 micrograms per cubic metre, more than 11 times the World Health Organisation’s safe limit.
“It has terrible effects on every part of your body,” said Dr Arvind Kumar, the chest surgery chairman at Sir Ganga Ram hospital, who compared the 999 AQI level recorded in the RK Puram area to smoking 50 cigarettes in a day. “ICUs are full of pneumonia patients. Lots of my patients are coming with coughs today. They are breathless.
“It can precipitate an acute asthma attack and in the long run it will increase their risk of lung cancer,” he said.
Those who work outside – such as the city’s fleet of rickshaw pullers – are hardest hit. Vikas Yadav, an immigrant from Bihar state, said he used to welcome the colder months when the threat from disease-carrying mosquitoes subsides.
Now, “my eyes get a burning sensation”, he said. “I fell sick last year. I don’t know whether it was from the air but I felt breathless and my eyes were itching. Doctors told me not to work early morning during winters.”
The smog was unsparing of Delhi’s wealthier set and its community of expatriate workers, many of whom gathered on Tuesday morning on the lawns of the Australian high commission for an annual champagne breakfast to celebrate the Melbourne Cup horse race.
“It was like being in Europe in the middle of winter on a misty morning,” said one reveller, Elizabeth Pennell, a lawyer with the World Bank. “It would have been romantic had the mist not been PM2.5.”
The crowd paired their race-day dresses and suits with pollution masks but Pennell said the foul air failed to dampen the mood. “You tuck up your children inside where the air is purified and for these few hours you risk your health to let your hair down,” she said.
“And then you can go back and lock yourself inside your apartment and breathe clean air – unlike most Indians.”
Delhi’s air quality is extremely poor for most of the year due to road dust, open fires, vehicle exhaust fumes, industrial emissions and the burning of crop residues in neighbouring states.
But conditions worsen in winter months when slow winds and cool temperatures trap pollutants closer to the ground.
But any lasting solution would need to simultaneously tackle the myriad sources of pollution and involve dozens of state and municipal governments in a country where law enforcement is notoriously patchy.
Though Delhi gets most attention, toxic air afflicts the entire north Indian plain, including parts of Pakistan. A study last year found the holy city of Varanasi had among the worst air in the country.
Airtel, the leading sponsor of the upcoming Delhi half-marathon, urged the city government to ensure the safety of runners, indicating that it may pull out of the event next year.
“Air pollution poses serious health risks and it is important that these concerns are addressed urgently and appropriately by the authorities for Airtel to continue associating with the event next year and beyond,” it said in a statement.
Research published in the Lancet last month found about 2.5 million Indians die each year from pollution, the highest number in the world.
Unprecedented levels of pollution this time last year forced schools to shut as authorities scrambled to contain the crisis.
The World Health Organisation in 2014 classed Delhi as the world’s most polluted capital, with air quality levels worse than Beijing. A 2015 study showed about half the Indian capital’s 4.4 million schoolchildren had compromised lung capacity and would never totally recover.