The advantage Delhi sought to gain from a series of environment-friendly measures, such as its Metro network and fleet of CNG buses and autos, has been lost with the levels of pollutants in the city having reached alarming levels, experts say. And the main cause for this, they feel, is the addition of more and more vehicles every day.
Recent studies have put Delhi more polluted even than Beijing, until now described widely as the worlds most polluted city. The annual study for the Environmental Performance Index conducted by the research centres at Yale and Columbia Universities ranked India last in terms of air pollutions effects on human health. It study found that levels of PM 2.5, a key yardstick among several kinds of polluting matter, were almost five times the safety threshold for humans.
The findings, particularly the comparison with Beijing, have caused outrage among Indian officials who cite the different characteristics of the two cities. There is no debate over the fact, however, that Delhis pollution levels are indeed rising, while Beijing has brought its levels down.
The Centre for Science and Environment has compared data from the Delhi Pollution Control Board and the Beijing Environmental Protection Bureau. In Beijing, PM 10 levels decreased about 40 per cent from 2000 to 2013; in Delhi this has increased about 47 per cent from 2000 to 2011. PM 2.5 (fine respirable particles) comprises particles not more than 2.5 micrometres in diameter and which are smaller than PM 10 (coarse particles).
The CSE has found that Beijings daily PM 2.5 levels for 2013 never exceeded 400 micrograms per cubic metre and averaged around 250. In Delhi, PM 10 and PM 2.5 levels rose 50 per cent in December and January. At 10 am on December 16, the monitoring station at R K Puram recorded 985, DPCB officials concede. The standard set by the Indian government is 60.
Said Dr Madhavan Nair Rajeevan, adviser to the Ministry of Earth Sciences, Experts are clearly puzzled that Delhi Pollution Control Board data from one station (Punjabi Bagh) showed the PM 2.5 level at 500 micrograms per cubic metre continuously for seven days in the first week of January. This value is extremely high which never happens even during Diwali.
DPCB officials too cautioned against a comparison. Delhi and Beijing have very different conditions. Moreover, comparisons shouldnt be made using real-time figures; instead a 24-hour mean needs to be calculated to give a more realistic assessment, said an official.
Delhi is completely landlocked. Beijing profits from a sea breeze that often drives away pollutants in the air. Delhi on the other hand often has no wind, thus trapping the pollutants, said R K Jenamani, director of IGI Airports Met office.
Environmental activists insist that the debate shouldnt be limited to comparing the two cities, but to treating the causes of Delhis high pollution.
While it is true that a comparison doesnt take into account the unique issues facing the two cities, it also remains true that Delhi has been very lackadaisical in its attitude towards air pollution. China has been much more stringent and it shows, their air pollution levels are lowering while ours are rising, said Anumita Roychowdhury of CSE.
Experts said an unabated rise in the number of vehicles plying in the city has undone the good done by CNG and the Metro. Unlike other countries, where steps have been taken to control the sale of vehicles, Delhi adds an average 1,000 cars daily. Delhi has 7.7 million vehicles until 2012-13 according to government figures, while Beijing has just over 5 million.
Vehicles are a major source of pollutants. As per a TERI and Indian Council on Clean Transport study released this month, implementation of of BS-IV fuel quality and vehicle emission standard must be made mandatory across the country by 2015 while BS-V fuels and vehicular emission standards must be adopted by 2017.
*With inputs from Anuradha Mascarenhas in Pune