A recent New York Times article uses data from the Delhi Pollution Control Committee to claim that Delhi’s smog and air pollution is much higher than that of Beijing.

A recent New York Times article which is based on data from the Delhi Pollution Control Committee claimed that Delhi’s smog and air pollution is much higher than that of Beijing. Given the kind of media attention Beijing’s smog receives, the NYT report comes as a shocking bit of news.

The report says that where fine particulate matter [PM2.5] is concerned, “Punjabi Bagh, a monitor whose readings are often below those of other city and independent monitors, was 473, more than twice as high as the average of 227 in Beijing. By the time pollution breached 500 in Beijing for the first time on the night of Jan. 15, Delhi had already had eight such days.”

It goes on to say, “Delhi’s peak daily fine particle pollution levels are 44 percent higher this year than they were last year, when they averaged 328 over the first three weeks of the year.”

PM2.5 particles are smaller than 2.5 microns in diameter, and can lodge deep into human lung and blood tissue and increase risk of heart and lung diseases, from strokes to lung cancer. PM2.5 particles are usually the result of combustion and emissions from automobiles, power plants and diesel powered vehicles.

The NYT report comes at time when India's environmental record continues to decline. The global Environmental Policy Index shows that India's ranked 155th worldwide and is the worst performer in G20 group. India is far behind Russia (73), Brazil (77) and China. The study is produced by researchers at Yale and Columbia universities, in collaboration with the World Economic Forum.

More disturbingly the EPI report states that the one area where India’s environmental performance lags exceptionally is air quality. The report says that, India's scores in this regard have declined by 100 percent in the last decade. It goes on to note that the stress of urbanisation coupled with insufficient investment in environmental protection are among the reasons why India’s air quality scores have declined in this dramatic fashion.

The report also points out that while the media spotlight has been on China, and in particular Beijing’s air quality, India ranks the worst in EPI’s air quality category. It adds that India and China have the highest average exposure to fine particulate matter (PM2.5) in the world.

While no one denies that Delhi does have a air problem, not everyone is convinced by the data. According to System of Air Quality Weather Forecasting and Research (SAFAR), a project of the official Indian Institute of Tropical Meteorology, data collected from across the nine monitoring stations at Delhi, the average air quality for PM 2.5 particles did not cross the 350 mark from 14th to 17th January, whereas in Beijing the PM2.5 particles had crossed the 600 mark.

Dr G Beig, Program Director at SAFAR, says the NYT data is surprising. He points out that when it comes to air quality data, “one needs to look at the ambient air average and not just the instant values. It’s very hard to believe that the PM2.5 value crossed 500 in Delhi overall. This usually happens in Delhi around Diwali season.”

However, he too concedes that the Delhi air quality has been declining. “When it comes to the winter, we’ve noticed that the air quality gets particularly poor. According to our own index, it even hits the critical level during some days, which is the lowest. There’s no denying that one of the major contributors to this is from the transport sector," says Beig.

Even if you take comparisons to Beijing out of the picture, Delhi’s air pollution level is alarmingly on the higher end of the scale. PM2.5 levels might not cross 500 on average, but the daily numbers are still much, much higher than the safety level -- 25 microgram per metre cube -- prescribed by the WHO and also higher than the more generous 60 microgram per metre cube limit set by the government of India.

Anumita Roy Chowdhury, Executive Director, Research and Advocacy at the Centre for Science and Environment, argues that the increasingly lax implementation of clean air policies have added to the problem.

“In the early 2001-2003, we saw some awareness with CNG coming in, industries being moved out and to some extent it helped stabilise the air pollution problem. It was still higher than the standard but those policies did arrest the increase," she says, "However post 2007-2008, the momentum has been lost and data has shown that the average levels of air pollution are rising. In particular, winters are turning out to be a bad time.”

One of the reasons for the smog and rising air pollution in winter is the weather and wind conditions, coupled with the increasing number of vehicles. “The weather has added to Delhi’s pollution vulnerability. The wind is almost calm once winter sets in post the Westerlies, pollution gets packed in the boundary layer and the ventilation outlet is closed. We don’t see the same level of pollution in summer or even the monsoon," Beig says.

The exponential rise in number of vehicles doesn't help.

“We have over 1400 vehicles being added to the city a day. The scale for tackling this has to be increased. From buses to metro, you need a nuanced approach to deal with air pollution. We only seem to have structures and policies based on private vehicles and cars. A complete paradigm shift is needed. Look at the number of diesel cars, the sales are only going up. They add significantly to emissions," Roy Chowdhury says.

On the question of Delhi vs Beijing, she points out that one needs to look at how Beijing also handles the situation when air pollution does go up. “They fix the number of cars on the road, they issue health advisories, alerts. That’s the kind of public awareness they have. They deal with the issue on a war-footing,” she argues.

Delhi may or may not be worse than Beijing, but it is certainly doing far less than Beijing to tackle its air pollution.