The coming week may bring cheer to many as it coincides with a fall in temperature. However, such a fall will come with its own cost with pollution spiralling to 'severe' levels.
"The first week of December will get colder with the temperature expected to dip by two to four degrees," said the Met department on Tuesday. However, environment experts caution that this dip in temperature could bring back the deadly smog that enveloped the national capital after Diwali.
This is because a drop in temperature as well as reduced wind speed will lead to a rise in air pollution. This happens, because in the absence of wind and sun, the pollutants suspended in the air are not able to disperse and thus remain hanging in the air.
A recent study done by the Centre for Science and Environment (CSE) of the air quality data collected by the Central Pollution Control Board (CPCB) between November 5 (after which emergency measures were implemented) and November 9, suggests pollution levels in the first week of December are expected to touch the 'severe' category. This can have serious health consequences for people.
"According to the inputs received from Met department, the maximum and minimum temperatures, which have remained above normal during November-end, are likely to drop by two to four degrees and one to three degrees respectively, by the first week of December," said VivekChattopadhyaya, senior scientist, CSE. He added that the wind speed too is likely to drop further from the already low (1.8 kmph). Already, the wind speed has fallen from 11 kmph on Sunday to 1.8 kmph on Tuesday.
Already, the effect of this on air pollution is showing. On Tuesday, the air quality in the Capital shifted from the 'poor' to 'very poor' category with the PM 2.5 levels (tiny particulate pollution that can clog lungs) increasing from 138 mg per cubic meters to 242 mg per cubic meters. On November 6, the week post-Diwali, the air quality levels had crossed hazardous levels when the PM 2.5 levels were recorded at 759 mg per cubic meters.
"We can again expect air pollution to touch its peak by the second week of December owing to a further dip in temperature and Delhi/NCR emissions. It is only now that that the measures taken by the Delhi government can be substantiated. This is because according to NASA images paddy burning in neighbouring states has reduced. What will count now are the emissions from Delhi/NCR region," Chattopadhyaya said.
Garbage and leave burning, he added, has still not stopped contributing to PM 2.5 levels. Also, the government must think of harsher measures for vehicular emissions by reducing the volume of vehicles, in particular diesel-run and improving public transport.
