If there was a gold medal for bad air, Delhi would be hard to beat.
Yet, despite high levels of air pollution, more than 30,000 people, many wearing masks, took part in the capital’s half marathon on Sunday. Organisers said they used devices on the route to transmit radio frequency waves to clear the air, but scientists were sceptical of these claims.
Delhi’s marathon, ironically, marked the beginning of the city’s smog season. But it has been creeping up on the capital for a few weeks now.
A fortnight ago, Nagendar Sharma was returning to Delhi from the hill station city of Shimla when he spotted smoke rising from the farms alongside the highway.
It looked like someone had picked up a box of matches and set the earth on fire. Lack of winds meant that the acrid smoke hung in the air.
Mr Sharma, the Delhi-based media adviser to the capital’s chief minister, was driving through Haryana, barely 70km (43 miles) from the capital.
When he stopped his vehicle to investigate he found that the farmers had begun to burn the stubble left over from harvesting rice. They said they had to remove the residue in three weeks to prepare the farms to sow wheat. They were burning the crop stubble as they could not afford the expensive machines that would remove them.
“It’s the same old story. Every year,” Mr Sharma said.
Every year, around this time, residents of Delhi wake up to a blanket of thick, grey smog. Pollution levels reach several times the World Health Organisation’s recommended limit. Last year, doctors declared a state of “medical emergency”; and hospitals were clogged with wheezing men, women and children.
Levels of tiny particulate matter (known as PM 2.5) that enter deep into the lungs reached as high as 700 micrograms per cubic metre in some areas. The WHO recommends that the PM2.5 levels should not be more than 25 micrograms per cubic metre on average in 24 hours.
Last winter Air Quality Index (AQI) recordings consistently hit the maximum of 999 – exposure to such toxic air is akin to smoking more than two packs of cigarettes a day. The city becomes what many call a “gas chamber”.
“This marks the beginning of the Great Smog that goes on to last for about three months, even though the crop residue burning lasts a few weeks. It is during this period that air quality indices hit their maximum possible limits, when visibility drops drastically, when regions even far away – such as Delhi – smell of burning gas,” says Siddharth Singh, energy expert and author of a book soon to be published, The Great Smog of India.
And although there are other reasons – construction dust, factory and vehicular emissions – it’s mainly crop residue that has emerged as one of the main triggers for the smog.
More than two million farmers burn 23 million tonnes of crop residue on some 80,000 sq km of farmland in northern India every winter.