Deterioration of air continues in Delhi, Sunday records season’s worst

The level of PM2.5 – tiny particles of dust, soot and smoke – shot up to its highest in Delhi since June at 232.2ug/m3.

The national capital recorded this season’s worst air quality on Sunday, with medical experts reporting a spike in respiratory ailments over the last two weeks. The overall air quality index (AQI) in Delhi touched 366, up from Friday’s level of 361. The AQI was in the ‘very poor’ category, above the hazardous 300-mark, for the fifth consecutive day.

Heavy smog in Patel Nagar, New Delhi on Sunday. (Sanchit Khanna/HT Photo)

The level of PM2.5 – tiny particles of dust, soot and smoke – shot up to its highest since June at 232.2ug/m3. The safe limit for PM2.5 concentration is 60ug/m3. Prolonged exposure to these ultrafine particles, which enter the lungs and blood, can cause severe respiratory problems.

Doctors in the city said the decline in air quality and a recent drop in temperature resulted in increasing number of patients reporting upper respiratory tract problems. The temperature dipped below 15 degrees Celsius last week, two degrees below normal.

Patients are also reporting allergic respiratory problems. “There is a steady increase in the number of patients coming to my clinic with allergic cold since mid-October. Usually, there is about a 30% increase in the number of such patients around Diwali, when the pollution levels increase and the temperature decreases, causing people’s immunity to go down,” said Dr Vikas Maurya, head of the department of pulmonology at Fortis hospital, Shalimar Bagh.

At 7pm on Sunday, the PM10 level in Delhi was recorded at 389.5 ug/m3, well past the safe standard of 100ug/m3. “PM10 and PM 2.5 levels are likely to shoot up further over the next three days. Pollutants are not getting dispersed and are getting trapping in the air because of the calm wind conditions,” said a senior CPCB official who did not wish to be named.

The Environment Pollution (Prevention and Control) Authority, a Supreme Court-mandated body to monitor pollution levels in the NCR region, has announced that pollution levels will peak after November 1, as winds flow from the northwest, bringing pollutants from burning stubble in neighbouring Punjab and Haryana. Epca said that the phenomenon, coupled with the onset of winter and the festive rush, will lead to a spike in air pollution. The Supreme Court recently lifted a blanket ban on the sale and purchase of firecrackers, which could also add to pollution in the first week of November.

Doctors said more cases of respiratory problems were likely after Diwali. “We will see an increase of nearly 20 to 30% in such cases in our OPD after Diwali. The pollution caused by bursting crackers is worse than from crop burning, because it releases sulphur dioxide and heavy metals into the air,” said Dr Srikant Sharma, senior consulting physician at Moolchand Medcity.

Between November 1 and 9 last year, Delhi’s air quality remained in the ‘severe’ category for a week, with AQI touching 486 on November 9. The toxic levels prompted authorities to declare a public health emergency. On a scale of 0 to 500, an AQI value between 301 and 400 indicates ‘very poor’ air quality. A value beyond 401 indicates ‘severe’ air quality.

Air pollution levels in the city have spiked despite the graded response action plan (Grap) being enforced beginning October 15. On?Saturday, Epca?announced a clutch of measures, including a complete ban on construction and excavation work across NCR between November 1 and 10, to curb pollution. The CPCB?also issued an advisory, asking citizens to avoid engaging in strenuous activity and exercising outdoors for extended periods. It also urged residents to use public transport during this period.