Delhi’s 13 hotspots continue to record alarmingly high levels of pollution

Delhi’s 13 pollution hot spots – identified first in 2018, jointly by the Central Pollution Control Board (CPCB) and the Delhi Pollution Control Committee (DPCC) -- for area-specific action, continue to record alarmingly high levels of pollution, data shows.

In a review meeting held by the DPCC on Tuesday evening, air quality data analysed between November 1 and November 8 shows that not only do these locations continue to record ‘severe’ air, but newer locations with high pollution levels have also emerged during this period.

These new locations -- Alipur, ITO, Nehru Nagar and Sonia Vihar -- all recorded at least four ‘severe’ air days during this period, levels exceeding even some of the existing pollution hot spots. While Alipur recorded five ‘severe’ air days during this period, the remaining three locations saw four severe days each, DPCC data shows.

Delhi’s original 13 hot spots were Jahangirpuri, Anand Vihar, Ashok Vihar, Wazirpur, Punjabi Bagh, Dwarka Sector 8, Rohini Sector 16, RK Puram, Bawana, Mundka, Narela, Okhla Phase II and Vivek Vihar. While locations such as Bawana, Mundka, Narela, Jahangirpuri and Wazirpur, Okhla-Phase II are largely dominated by industries, residential hot spots such as Dwarka’s sector 8, Rohini’s sector-16 and Punjabi Bagh have different sources of pollution. RK Puram and Anand Vihar are polluted mostly because of heavy traffic movement around them.

“Action can only be focused if each hot spot’s top sources of pollution are known. One can undertake measures such as sprinkling of water, but long-term action can only be driven if agencies know specific sources of pollution. Even then, it can take some time for pollution levels to drop as background emissions will remain high across the city,” says Tanushree Ganguly, Programme Lead at the Council on Energy, Environment and Water (CEEW).

Among the emerging hot spots, ITO is characterised with heavy traffic, with vehicular emissions playing a key role in the PM 2.5 levels, especially during idling of vehicles. Alipur, located on the highway exiting Delhi from the north, also receives heavy traffic, in addition to receiving emissions form industries and the nearby Bhalswa landfill. The largely residential localities of Sonia Vihar and Nehru Nagar meanwhile may be recording instances of bio-mass burning, in addition to vehicular emissions and dust-upliftment.

Dipankar Saha, former head of CPCB’s air laboratory, says emissions from vehicles can end up releasing secondary aerosols and toxic chemicals in the air. Each time vehicles move, dust re-suspension also occurs. “If meteorological conditions are not ideal, these emissions can get trapped in the air and with dust, stay in the air for a long period. Stations located close to a source can record such high concentration easily,” he explains.

On November 5, an anti-smog gun was installed at ITO by the Delhi government, to control upliftment of dust and pollutants in the area. The smog-gun was also inspected by environment minister Gopal Rai.

Meanwhile, senior environment department officials said Alipur in north Delhi has a locational disadvantage, with close proximity with the Sanjay Gandhi Transport Nagar and the Bhalswa landfill. The area also reports among the highest cases of garbage dumping and open garbage fires, according to action-taken reports.

“Alipur is among the areas where a lot of work needs to be done. The pollution levels here remain higher than the city average because of the large movement of trucks and heavy vehicles. In this area at night tyres and other waste from vehicular repairs are set ablaze. The close proximity with the landfill, which also reports frequent fires, is also a problem,” the official explained.

Residents also said that dust is another factor that is prevalent in this part of the Capital. Since many of the internal roads here are unpaved and broken, road dust constantly remains suspended in the air and is made worse by the high vehicular movement.

In south Delhi’s Nehru Nagar, close proximity to the Ring Road was the primary cause of pollution. Between November 1 and November 8, high cracker bursting in this residential area could also be another reason for the sudden dip in air quality.

Sonia Vihar, another residential suburb in north-east Delhi, is another area which could meanwhile be getting impacted by emissions from biomass burning, as well as dust from unpaved roads along the river’s banks.

Professor Mukesh Khare from IIT Delhi said while dust and garbage burning are two factors which can lead to a spike in residential areas such as Nehru Nagar and Sonia Vihar, it is difficult to pin-point any additional sources of pollution in such a short window of analysis.

He says moving ahead, identifying new hot spots should be done on the basis of the total emissions being generated in the area and not the PM 2.5 or PM 10 concentration. “PM 2.5 and PM 10 concentration is influenced by meteorology. If the location is near the border, trans-boundary pollution may impact it. Similarly, if there are calm winds there, pollutants will accumulate there. In order to identify a pollution hotspot, locations with the most emission count should be prioritized,” he said.