POLLUTED DELHI CAN TAKE LED FROM BEIJING IN BATTLE TO CLEAN UP ITS 'GAS CHAMBER' AIR
▶ Experts say tough regulations can cut smog after Indian state forced to declare state of emergency
Pollution-choked Delhi should follow the example of Beijing to clean up its act.
While New Delhi and India’s other conurbations remain blighted by bad air quality, researchers are starting to see signs of improvement in some Chinese cities.
“We’ve seen the air quality in Beijing improving. That demonstrates that informed regulation can have a positive impact,” said Prof William Bloss, of the University of Birmingham in the UK, who has been studying the sources of Delhi’s smog.
Prof Bloss, who has also analysed air quality in the Chinese capital, said: “It’s a problem we can solve. It’s not something we have to live with as the price of development.”
Delhi was plunged into a state of emergency after its air quality dropped to its worst levels in three years, causing dozens of flight cancellations, school closures and an increase in asthma attacks.
Television footage of toxic smog enveloping the city and residents walking the streets in face masks has shocked the world in recent days.
A public health emergency was declared on Friday and Delhi’s chief minister, Arvind Kejriwal, said the city had turned into a “gas chamber”.
With conditions extreme even by the standards of one of the world’s most polluted cities, officials advised the 46 million people living in the greater Delhi area to stay at home and to keep their windows closed.
Authorities also restricted the use of cars by banning vehicles with registration plates ending in odd or even numbers on alternate days until November 15.
The concentration of PM2.5 – particulate matter less than 2.5 micrometres in size – rose to about 900 microgrammes per cubic metre this week, far exceeding the World Health Organisation’s recommended safe annual average of just 10 microgrammes per cubic metre.
Such fine particles – so small they are invisible to the naked eye – are emitted from a variety of sources, including cars, planes, power stations and farm fires. They pose a particular danger as they hang suspended in the air for long periods and are easily inhaled.
Proff Bloss’s research project titled “An integrated study of air pollutant sources in the Delhi national capital region” revealed that the city’s pollution problems “overwhelmingly” revolve around PM2.5s, contrasting with some western cities where nitrogen dioxide from
vehicles ranks as highly as particulate matter.
Local press reports citing satellite data suggested that there were as many as 3,000 farm fires in the neighbouring Indian states of Punjab and Haryana last week. The fires rage at this time of year because farmers burn off stubble to allow a fast turnaround between crops.
State governments have faced stinging criticism for failing to clamp down on the practice, with India’s Supreme Court accusing them of “asking
people to die”. “It is too much. No one is safe even inside their house,” judges said. “It is atrocious.”
Pollution from within the city, such as traffic emissions, contributes “to a lesser extent” to Delhi’s appalling air quality, Prof Bloss said, although its effects are still significant.
Other sources within the city include solid-fuel burning by householders, and the burning of rubbish, which takes place because waste-disposal systems are hopelessly inadequate. The setting off of firecrackers to celebrate the Diwali festival, which ended last week, was also blamed for the smog.
“We have to move to clean energy options, but there are an infinite number of small sources [of pollution],” said Prof Sachchida Tripathi, of the Indian Institute of Technology Kanpur.
He said solid fuels should be replaced with liquefied petroleum gas, while flue-gas desulphurisation should be introduced at power stations to reduce sulphur dioxide emissions, which are higher in India than anywhere else in the world. To get people off the roads, experts say that public transport in Delhi must improve, especially as the city grows.
“The public transport [network] is not reliable enough to transport people from one place to another,” said Prof Prashant Kumar, from the University of Surrey in Britain, who is also involved in the Delhi air pollution research project.
“It’s a city that is growing. You cannot keep taking people in without putting in the proper infrastructure.”
Delhi’s air pollution woes are shared by many Indian cities, with a survey released this year by the environmental group Greenpeace showing that the country contains 22 of the world’s 30 most polluted cities. Delhi is the most polluted world capital and the 11th most polluted city overall.
In total, 99 per cent of cities in south Asia reportedly exceed the WHO’s recommended limit for PM2.5, and all Middle Eastern and African cities in the survey breach the limit.
Globally, as many as seven million people are thought to die each year because of the health effects of poor air, which include cancer, heart disease and respiratory conditions.