Being in Delhi at this time of the year instils a sense of déjà vu. Eyes burn, lungs choke and a nebuliser is kept handy. Yes, it is the onset of winter in the national capital. And predictably, the air quality has hit ‘severe’ category making it a public health emergency.
Yesterday, on November 3, the levels of two primary pollutants in Delhi — PM10 and PM2.5 — as recorded by SAFAR (System of Air Quality and Weather Forecasting and Research) of the Union ministry of earth sciences — hit 739 microgram per cubic metre (µg/m3) and 558 µg/m3, respectively. Both falling under ‘severe’ air quality category. The overall air quality index (AQI) in the capital touched 708.
Air quality at various locations, as recorded by the Delhi Pollution Control Committee (DPCC), showed pollution levels had way exceeded the prescribed standards. For instance, on November 3 at 15:50 hours, PM10 and PM2.5 levels at Major Dhyan Chand National Stadium (near Indian Gate) were 669 µg/m3 and 501 µg/m3, respectively.
The national ambient air quality standard for PM10 (particulate matter size less than 10 µg) is 100 µg/m3 and PM2.5 (particulate matter size less than 2.5 µg) is 60 µg/m3. The World Health Organisation recommends even stricter air quality standards — 50 µg/m3 for PM10 and 25 µg/m3 for PM2.5.
Clearly, over 46 million residents in the National Capital Region (NCR) are right now breathing poison. Other parts of north India are only a shade better. Today, on November 4, the air quality in the national capital is still in ‘severe’ category. As per SAFAR, PM10 and PM2.5 are 571 µg/m3 and 438 µg/m3, respectively.
Air quality at various locations, as recorded by the Delhi Pollution Control Committee (DPCC), showed pollution levels had way exceeded the prescribed standards.
‘Severe’ category of air quality is a “Health Warning of Emergency Conditions [with] Serious risk of respiratory effects in general public”, warns SAFAR. In such a scenario, SAFAR recommends everyone to stop all physical activity outdoors. Further, people with heart or lung disease, older adults, and children are advised to remain indoors and keep activity levels low.
Keeping in mind the ‘severe’ air quality, the Environment Pollution (Prevention and Control) Authority, a Supreme Court mandated panel commonly known as EPCA, declared public health emergency in Delhi and NCR. It has banned all construction activity in the region till November 5, including banning of crackers all through the winter season. Air quality data shows that air pollution levels, which were already high in Delhi, jumped manifold post Diwali.
The chief minister of Delhi, Arvind Kejriwal, has declared shutting down of schools till November 5. All schools in Noida and Greater Noida are also to remain shut till November 5 due to high levels of air pollution.
Meanwhile, the Directorate General of Health Services of the Delhi government has also issued a health advisory to the public for protection from air pollution. Among other things, it has advised people to avoid outdoor physical activities, especially during morning and late evening hours, and suggested use of certified N95 masks. Odd-even scheme has taken off in the national capital from November 4 to November 15. It is a rationing system, first implemented in 2016, where cars with odd and even number plates ply on alternate days to reduce vehicular pollution.
But, this isn’t the first time air quality in the capital has touched ‘severe’ category for consecutive days leading to a public health emergency. Every year, around the onset of winter, air quality in the capital deteriorates drastically due to both natural (unfavourable winds, inversion) and humanmade factors (see figure: Air quality in Delhi — 2018 vs 2019).
Figure: Air quality in Delhi — 2018 vs 2019
The national ambient air quality standard for PM2.5 is 60 µg/m3
Source: http://safar.tropmet.res.in
This is also the time when farmers in Punjab and Haryana shift from kharif crops to rabi crops and in the process burn paddy stubble, which contributes to air pollution. But, what exactly is the pollution load remains debatable. These farmers are blamed annually for ‘severe’ air quality in the NCR.
As Sunita Narain, director general of New Delhi-based Centre for Science and Environment and a member of EPCA writes: “… it is important to note that stubble burning is not the primary cause of pollution. The sources of pollution remain constant through the year — it is cleaner because through the year, winds disperse pollutants and there is circulation in the atmosphere (defined as the ventilation index). So, sources do not disappear, but pollution is not in our face.”
Last October, the Union ministry of earth sciences released its emissions inventory that showed transport and industry sectors to be the two biggest polluters in the NCR. It noted that emissions from the transport sector contributed over 40 per cent of the total pollution load in the NCR. Industry, too, was found to be a significant contributor. However, this inventory did not look into stubble burning.
Another 2019 study – ‘What is Polluting Delhi’s Air? Understanding Uncertainties in Emissions Inventory‘ – by the Council on Energy, Environment and Water (CEEW), New Delhi noted: “Transport sector is the largest emitter of PM2.5 particles (17.9 per cent to 39.2 per cent) and road dust is the largest contributor of PM10 particles (35.6 per cent to 65.9 per cent)” in Delhi NCR (see bar graphs: Sector-wise contribution of pollution load in Delhi NCR).
Figure: Sector-wise contribution of pollution load in Delhi NCR
Sector-wise contribution of PM2.5 (in %) Sector-wise contribution of PM10 (in %)
Source: Jalan, Ishita and Hem H. Dholakia. 2019. What is Polluting Delhi’s Air? Understanding Uncertainties in Emissions Inventory. New Delhi: Council on Energy, Environment and Water.
According to SAFAR, as of November 3 this year, the share of external bio-mass in PM2.5 in the NCR is 12 per cent and is expected to rise. It was as high as 44 per cent three days back on October 31. Fire count data shows that stubble burning has remained a problem even this year (see figure: Fire counts 2018 vs 2019). But, we must remember that stubble burning ends by mid-November whereas the NCR continues to have very poor air quality till almost January.
Figure: Fire counts 2018 vs 2019
Without doubt the issue of stubble burning needs to be addressed, as it not only contributes to air pollution, but is also a waste of resource. And, the best time to act on it was yesterday. Also, bursting crackers when the city already has ‘very poor’ or ‘severe’ air quality, and because the farmers in neighbouring states are burning stubble, defies common sense.
It is imperative to control the local sources of pollution. “… the real and long-term answer will be in moving completely out of coal and other dirty fuels to cleaner natural gas or electricity. And in moving us from cars to massively augmented and well-connected public transport,” writes Narain.
We need to invest big time in buses and other non-motorised ways of transportation, as almost 40 per cent of pollution load is coming from the transport sector. Dust management (construction and roads), waste segregation and controlling garbage burning, banning burning of coal and other dirty fuels in industries are some other measures that need immediate attention and strict implementation.
