Clear Blue Skies Of COVID-19 Lockdown Are Things Of Past As Air Pollution Grips Delhi-NCR

While several reasons contribute to air pollution, vehicular emission remains a major source of pollution in cities like Delhi. Vehicular emissions turn air toxic which has large-scale implications for the health of individuals.

Air Pollution levels have shot up across Indian cities, especially in Delhi and other cities of the National Capital Region like Noida, Gurgaon, Ghaziabad, Faridabad etc. According to the data provided by the Central Pollution Control Board (CPCB) website, AQI levels in Delhi on Tuesday (November 7) remained in the severe category - Anand Vihar recorded 432, RK Puram measured 437, Punjabi Bagh showed 439, and New Moti Bagh registered a reading of 410. In Noida, a reading at Sector 62 at 6 am showed an AQI of  384 (very poor) while in Gurugram, a reading at Sector 51 at 6 am showed an AQI of 399 (very poor).  

While several reasons contribute to air pollution, vehicular emission remains a major source of pollution in cities like Delhi. Crop burning by neighbouring states of Punjab and Haryana, construction activities, and cold weather are some of the other reasons for air pollution in NCR. 

Clear Blue Skies During Covid-19 Lockdown

As economic activities came to a halt and a lockdown was implemented in March 2020, air across cities cleared up. Between March 25 and May 18, 2020, Delhi saw a drastic drop in air pollution levels and according to reports, the air quality index (AQI) in the capital remained in the “satisfactory” category for most of the time.

According to news articles, the Centre for Science and Environment said in a report, "In Delhi-NCR, one of the major factors that led to the drop in pollution was a 97% reduction in overall traffic and 91% reduction in trucks and commercial vehicles entering the capital during April, as compared to the pre-lockdown months of December-January." This clearly shows how vehicular emissions greatly impact Delhi's pollution levels. More than three years later when economic activities are in full swing, and life is so-called back to normal, Delhi is reeling under the impact of toxic air.

Particulate Matter: Impact Of Vehicular Emission On Health

Vehicles emit several pollutants depending upon the quality of the fuel they consume, engine efficiency, vehicle type, maintenance of vehicle and more. The major pollutants released as vehicle/fuel emissions include particulate matter, carbon monoxide, nitrogen oxides, photochemical oxidants, air toxics like benzene, aldehydes, and oxides of sulphur, among others. All these pollutants have a severe impact on a person's health. 

Talking about vehicular emissions, Dr Viswesvaran Balasubramanian, Consultant Interventional Pulmonology and Sleep Medicine, Yashoda Hospitals, Hyderabad, says, "Carbon monoxide is one of the most important vehicular pollutant produced by the incomplete combustion of carbon-containing fuels in vehicles. When inhaled, it binds to haemoglobin in the bloodstream, reducing the blood's ability to carry oxygen. This can lead to symptoms like shortness of breath, chest pain, and even hypoxia (oxygen deficiency). In individuals with pre-existing respiratory conditions, such as chronic obstructive pulmonary disease (COPD), CO exposure can worsen their symptoms."

He adds that nitrogen dioxide (NO2), another vehicular pollutant, irritates the airways which can lead to inflammation of the respiratory tract. This can worsen conditions like bronchitis and asthma. Prolonged exposure to NOx is associated with increased respiratory symptoms and reduced lung function.

"Apart from gases, particulate matter (PM2.5 and PM10) from vehicle emissions can be inhaled deep into the lungs. This can cause or exacerbate respiratory issues, such as bronchitis, asthma, and reduced lung function. Long-term exposure to PM has been linked to an increased risk of lung cancer and other respiratory diseases," says Dr Balasubramanian.

Sulfur Dioxide (SO2) is primarily emitted from industrial sources and power plants, and vehicle emissions can also contribute to SO2 levels in the air. SO2 can irritate the respiratory system, leading to symptoms like coughing, wheezing, and shortness of breath. It can also worsen asthma and other respiratory conditions, the doctor says.

"Reducing exposure to these pollutants is essential for protecting respiratory health. This can be achieved through measures like using cleaner transportation options, supporting regulations for stricter vehicle emissions standards, and living in areas with reduced traffic-related air pollution. Public health initiatives and policies are crucial in addressing the impact of vehicle pollution on respiratory health," suggests Dr Balasubramanian.