New Delhi, November 6, 2012: The dense smog which had been throttling Delhi for the past few days has lifted partially today, but it may come back with renewed vigour, as the factors causing it remain in force \u2013 says Centre for Science and Environment (CSE).
\nCSE has reviewed the magnitude and severity of the smog. Its researchers believe that while every winter, the calm and cool weather leads to a heavier pollution load on Delhi, this year, the capital is seeing a massive growth in actual pollution levels. The levels of respirable particulate matter (PM10) have surged 47 per cent — from 191 microgramme per cubic metre in 2000 to 281 microgramme per cubic metre in 2011. In the same period, nitrogen dioxide levels have increased from 41.8 microgramme per cubic metre to 66 microgramme per cubic metre (a 57 per cent jump).
\nThis hike in pollution levels has led to the creation of the deadly smog. Says Anumita Roychowdhury, executive director in charge of the air pollution and transportation programme at CSE: \u201cUnfortunately, despite the scary hard facts about the elevated cocktail of pollution and health risks, the problem is being dismissed as a mere weather phenomenon. In other parts of the world, governments issue warnings and take pollution emergency measures during such severe pollution episodes to protect public health. But we are doing nothing.\u201d
\nDelhi localities are in grip of multi-pollutant crisis: Particulate matter is not the only thing choking us — nitrogen dioxide, carbon monoxide, ozone and benzene levels are playing havoc as well, as per official monitoring. Some of these pollutants come predominantly from vehicles.
\nKiller particles: PM2.5 levels are exceeding the standard by 4-6 times. An increase of only 10 microgramme per cubic metre in PM2.5 is associated with significant increases in health risks. High exposure is known to lead to increased hospitalisation for asthma, lung diseases, chronic bronchitis and heart damage. Long-term exposure can cause lung cancer.
\nHigh NOx: NO2 levels are exceeding standards in areas like Mandir Marg, Civil Lines and R K Puram. Levels of nitrogen oxides (NOx) have been increasing in the city — a clear sign of pollution from vehicles. NO2 can trigger serious respiratory condition and sudden death syndrome among infants.Ozone, the new threat: Eight-hourly ozone levels show slight increases over time \u2013 they exceed the standards almost on a daily basis in a few locations. Ozone is not directly emitted by any source but is created from reaction between NOx and the volatile organic compounds in the air under the influence of sunlight.
\nPollution correlates with peak traffic hours and freight movement: Data from the Delhi Pollution Control Committee in different localities shows that pollution levels go up significantly during peak traffic hours compared to off-peak hours. For instance:
\n\u00b7 In R K Puram, Mandir marg and Civil Lines, both PM2.5 and NOx concentrations are high during peak hours.
\n\u00b7 Pollution levels are extremely high in Anand Vihar which witnesses very heavy traffic due to a lot of inter-state movement of vehicles.
\n\u00b7 In Civil Lines, PM2.5 levels are very high even during night; this could be due to the movement of goods traffic<\/p>\n\n