NEW DELHI: A day after World Health Organization's latest urban air quality database showed that Delhi has the worst air quality among 1,600 cities in 91 countries, government officials chose to split hairs over the published numbers while environmentalists stressed that the country should get on with addressing air quality concerns urgently.
Getting into an unavailing comparison with Beijing, the ministry of earth sciences said in its statement: "World Health Organization (WHO) has overestimated India's data and underestimated Beijing's".
It said the air quality records with Indian Institute of Tropical Meteorology (IITM) differ from the WHO database released in Geneva on Wednesday.
"If we compare yearly averages for each year from 2011 to 2014, both cities (Delhi and Beijing) are almost comparable. Delhi's air quality is better than Beijing's in summer and much better in monsoon. Delhi's annual average ranges from 110 to 120 microgram per cubic metre but WHO has overestimated it as 153 g/m³ and Beijing's average has been underestimated," said Gufran Beig, chief project scientist, System of Air Quality Weather Forecasting and Research at IITM. "It is Delhi's winter pollution and sudden spikes triggered by meteorology that push up the annual average. There are implications from climate change as well," he added.
The WHO database provides 2010 figures for Beijing versus 2013 figures for Delhi. "I think India has been sharing its data openly but that's not the case with China. Why would they not share 2012 and 2013 data?" said an official from Delhi Pollution Control Committee (DPCC).
Environmentalists, however, said it doesn't matter whether Beijing or Delhi has the dirtier air as both have very high levels of pollution. IITM's own data suggests that Delhi's annual mean PM2.5 (fine, respirable particles) has been marginally higher than that of Beijing's in 2011, 2012 and 2013.
"Why are they so hung up over Beijing's air quality? Is Beijing the only benchmark for us? We are not just breaching our own standard but are several times higher than WHO's standards," said Anumita Roychowdhury, head of Centre for Science and Environment's (CSE) Clean Air programme.
"Isn't that a good enough reason to take aggressive action? Why can't we accept the problem? If they want to emulate Beijing, they should have aggressive policies on capping the number of cars and implementing Euro 5 emission standards," she added
