Defending Delhi's Air Quality?

Delhi's air quality is indeed very poor but not as poor as Beijing's, claim scientists. After an international newspaper recently reported that Delhi's air quality this January has been worse than Beijing's, System of Air Quality Forecasting and Research (SAFAR) - under the Union earth sciences ministry - issued a clarification on Tuesday.

An emissions inventory for Delhi @ 1kmx1km resolution

Link to the article in Times of India.

Delhi's Air Quality is Twice as Bad as Beijing

Data from nine monitoring stations in Delhi states that PM2.5 (fine respirable particles) never crossed 350 micrograms per cubic metre while in Beijing it did cross 500 microgram per cubic metre and went up to 650 micrograms per cubic metre. The levels of PM2.5 are crucial because their impact on health is far more serious than that of PM10 (coarse particles). Since these particles are very small in size, they can easily enter the body and affect lung function. They are associated with increased rates of chronic bronchitis, mortality from lung cancer and heart disease. The standard for PM2.5 levels is 60 microgram per cubic metre.


Beijing's Bad Air Quality is a Step Up for Smoggy Delhi


"It is true that Delhi is reeling under very poor air quality. But in terms of concentration of pollutants, we are doing far better than Beijing which has declared emergency conditions because of their air quality. Our PM10 (coarse particles) and PM2.5 are both high but not extreme. High PM 10 levels in Delhi can be attributed to road and construction dust while high PM2.5 levels in Delhi can be attributed to incomplete combustion of fossil fuels and biomass," said Gufran Beig, chief project scientist at SAFAR.

Air Pollution in Delhi - Winter Time Highs and Blame Games

Several air pollution experts and environment ministry officials sought clarification from IITM on whether Delhi had poorer air than Beijing. Scientists claim that one of the reasons why there could have been a misunderstanding about Delhi's air quality is because the hourly values are often not representative of the 24 hour average. "What matters is the exposure of well-mixed ambient air on a longer period," said Sunil Peshin from Indian meteorological department.

Real Time Air Quality and Air Quality Index for Delhi, India

However, there is no doubt about the fact that Delhi's air quality is one of the poorest in the world and that emissions in the capital are on a steady rise. TOI had reported on Monday how PM 2.5 emissions, which were 94.26 Gg/year in 2010, had increased to 107.5 Gg/year by 2013. This increasing trend was particularly seen over Rajiv Chowk, Sansad Bhawan, India Gate, IGI airport, Okhla industrial area, Pragati Maidan, IP estate and Janakpuri.

Health impacts of air pollution in Delhi