Come winter, India’s capital New Delhi and the National Capital Region (NCR) are enveloped in thick smog, to which is added toxic air pollutants spewed by burgeoning vehicular traffic, increasing industrial activity and unbridled stubble-burning in farms in the neighbouring States of Haryana, Punjab and Uttar Pradesh (UP).
Visibility is reduced to zero, making driving and even walking hazardous. People fall ill and schools are closed.
This is an annual occurrence, which is hotly debated every year and various ad-hoc measures are taken by the authorities to control it. But a permanent solution is still a far cry from being found or implemented.
This year, air pollution spiked to 100 times the World Health Organisation (WHO) health limit. According to The Guardian, the winter in New Delhi generally begins with an Air Quality Index (AQI) near the worst possible level of 500. This year, schools were shut and non-essential construction was banned around New Delhi.
Although there are various reasons for this “climate catastrophe” the general tendency is to blame farmers who burn agricultural stubble in the States of Haryana and Punjab which surround the NCR. They burn stubble in the crop planting season.
The smoke from it is carried by winds which gather other pollutants along the way into New Delhi. A sharp drop in temperatures during winter then traps the particles in the lower atmosphere.
Causes of pollution
In recent days, the State of Punjab saw a 740 percent increase in farm fires, with more than 1,000 recorded in a single day. The other causes of pollution in New Delhi are, of course, car emissions, construction and the burning of rubbish at waste plants.
Home to 33 million people, Delhi including the NCR has a long record of being the most polluted place in the world. According to this year’s Air Quality Life (AQL) index, compiled by the University of Chicago’s Energy Policy Institute (EPI), the denizens of Delhi would shorten their lifespan by 11.9 years due to the poor air quality.
The typical illnesses in Delhi in this season are: coughs, colds, watery and irritated eyes, and breathing problems. People of all ages are affected. It has been so severe lately, that doctors have been advising the wearing of masks that can filter Particulate Matter (PM) – not the surgical masks worn to ward off Covid.
According to a study by the Indian Council of Medical Research (ICMR), air pollution was responsible for 1.67 million deaths in India in 2019 alone, and New Delhi had the highest Per Capita Mortality Rate due to air pollution among all Indian States that year.
The local Delhi Government has been sprinkling water on roads to reduce the dust. It has built two 80 ft., high “smog towers”, costing more than US$ 2 million each to clean the air.
According to a 2021 study, stubble burning’s contribution to Delhi pollution was 25 percent. Stubble burning emits harmful gases like Carbon Monoxide (CO), Methane (CH4), carcinogenic Polycyclic Aromatic Hydrocarbons (PAH) and other Volatile Organic Compounds (VOC).
A 2015 study conducted by the Indian Institute of Technology (IIT) in Kanpur found that 17-26 percent of all PM in Delhi during winters emanate from biomass burning.
The direction of the wind is also a contributory factor. The predominant direction of winds in Delhi post-monsoon is North-Westerly. According to a study conducted by the National Physical Laboratory (NPL) of India, 72 percent of Delhi’s wind in the winters comes from the North-West. It is these winds which bring dust and smoke to the City when stubble is burnt in Haryana and Punjab.
“Temperature Inversion” (TI) is the other key factor. TI creates a layer of warm air above a layer of cold air, trapping the pollutants near the ground. TI affects Delhi’s pollution during winter when the weather is cold and calm. Pollutants from stubble burning, vehicle emissions, industrial emissions, and other sources accumulate in the lower atmosphere and form a thick layer of smog.
Dry and still air also causes an accumulation of pollutants. In winter, there is less rainfall and reduced wind speed, which means that pollutants do not get washed away or diluted by fresh air. They remain suspended in the air for longer periods of time.
Vehicular and industrial emissions are an increasingly important cause of smog. New Delhi has a large middle class population, with each family having more than one vehicle. These emit harmful gases and particles as do the industries in and around Delhi.
A study by the IIT, New Delhi noted that vehicular emissions contributed around 25 percent to Delhi’s PM 2.5 levels. PM is a mixture of solid and liquid particles that are suspended in the air. These are categorised into coarse, fine and ultrafine. PM 2.5 are fine particles that have a diameter of less than 2.5 micrometers (more than 100 times thinner than a human hair). These remain suspended in the air for longer durations.
Health risk
The health risk with PM 2.5 is that they can travel deep into the respiratory tract, reaching the lungs and finally entering the bloodstream. While celebrating Deepavali this weekend, the people will burst crackers, and the smoke from the crackers will add to the pollution. The authorities were expected to ban fireworks in Delhi during Deepavali and some other States have imposed a time limit on firecracker use during this period.
The Delhi State Government recently launched a major anti-pollution campaign, which includes tree transplanting and other such initiatives. It has also launched a mobile app that enables citizens to report any instances of pollution such as garbage burning, industrial emissions, or traffic congestion. They also plan to create artificial rain to ward off the smog.
The National Agricultural Institute (NAI) at Pusa near New Delhi helps farmers decompose the crop residue in their fields without burning it. The Government provides free spraying of a bio-decomposer in Delhi’s farmlands.
The use of water sprinklers, mechanised road sweeping machines, anti-smog guns, and sprinkling facilities on high-rise buildings to reduce dust and PM in the air would also help reduce air pollution.
To curb industry pollution, the Delhi Government is supplying Piped Natural Gas (PNG) to industries and has set up India’s first e-waste eco-park. Drones could be used to identify and disperse pollution hotspots as a proactive approach to managing air quality.
The Delhi Government is to institute the odd-even car-rationing scheme after the Supreme Court (SC) reviews its effectiveness and issues an order. On Tuesday, the Apex Court had questioned the effectiveness of the Delhi Government’s car-rationing scheme, referring to it as “nothing but optics”. Earlier, the SC had rapped Punjab for allowing the farm fires to burn unchecked.
This phenomenon is not however limited to India. Singapore and Malaysia suffer from haze when farmers burn their fields in neighbouring Indonesia and even Sri Lanka experienced a minor haze carried over from India last year.
