Air Pollution In India: A Complex Issue

It is expected that by 2030, around 50% of the global population will be residing in urban areas and more than 80% of population of urban regions will be exposed to harmful levels of pollution. The degradation of ambient air quality in the urban regions of India is a complex issue affected by multiple factors and agents.

• Air pollution is the contamination of indoor or outdoor air due to the presence of substances that are harmful to the human health and other living beings. The most common causes of air pollution include partially combusted exhaust gases which are a by-product of industry, including SO2 and CO, and other carcinogenic gases released through industrial, commercial and other economic activities.
• Rising urbanisation, industrialisation, and associated anthropogenic activities are the prime reasons that lead to air pollution.

Causes of Air Pollution in India

• Vehicular and Transport Emissions: Transportation sector is the main contributor of air pollutants in Indian cities. Increase in number of vehicles as compared to the limited road infrastructure leads to congestion and traffic jam, increasing the levels of pollution. Carbon monoxide (CO), NOX, and Volatile Organic Compounds are the major pollutants from vehicular emissions.
  • Road dust is a major contributor to particulate matter emissions in urban cities of Delhi, Mumbai, and Kolkata. Factors leading to high traffic emissions include lack of enforcement of laws, heterogeneous nature of vehicles, and relatively poor quality of fuel.
• Industrial Processes: India has witnessed large-scale industrialization over the past few decades. Increasing emissions from unregulated industries has led to degradation of air quality in urban areas. The major pollutants from these industries comprise SOX, NOX, and CO2 emissions.
• Agriculture: Key emissions from agricultural activities include ammonia (NH3) and nitrous oxide (N2O). Methane emissions are common due to fermentation processes, nitrogen excretions from animal manure, such as CH4, N2O, and NH3, methane emissions from wetlands, and nitrogen emissions from agricultural soils.
  • Agricultural processes, such as 'slash and burn' are prime reasons for photochemical smog resulting from the smoke generated during the process.
  • Crop residue burning is a common process that results in toxic pollutant emissions.
• Power Plants: Thermal power plants manufacture more than 70% of the total power generated in India. Thermal power plants are the main sources of SO2 and suspended particulate emissions.
• Waste Treatment and Biomass Burning: Due to the problem of untreated municipal waste in India, which is dumped into open yards and landfills, it leads to various Green House Gas Emissions. It is the primary cause of PM2.5 and PM10.
  • The open burning of wastes, including plastic, produces toxic and carcinogenic emissions.
• Indoor Pollution: Use of fossil fuels such as Kerosene, cow dung, wood, crop waste, etc. leads to indoor air pollution, which directly affects human health.
• Construction and Demolition Waste: It is generated by construction and demolition activities. This type of waste contributes to greenhouse gases emissions.

Impacts of Air Pollution

• The terrestrial ecosystem is affected by ground air pollution which manifests in the form of respiratory and pulmonary illness in humans.
• The effects on the marine ecosystem include acidification of lakes, eutrophication, and mercury accumulation in aquatic food.
• The deposition of sulphate, nitrate, and ammonium causes soil acidification.
• Acid rain caused by the deposition of SO2 and NOX emissions in the atmosphere can have harmful effects on our biodiversity.
• SOX and NOX emissions can harm the flora, fauna, material surfaces, and even damage buildings and structures. The negative effects may be in the form of discolouration, loss of material, structural failing etc.
  • For e.g.: Taj Mahal turning yellow as a result of SOX emissions from industries and acid rain and Hyderabad's Charminar turning black due to its location in a highly polluted area.
• Ozone pollution results in reduced photosynthesis and slower growth in plants and in humans, it can affect the lung tissues causing respiratory conditions, such as asthma.
• Emissions such as PM, O3, SOX and NOX have the potential to damage the cardiovascular and respiratory systems of humans.
• A relation between premature deaths and air pollution has also been established. Pollution-related deaths numbered 1.67 million in 2019.

Measures To Tackle the Complexity of Air Pollution

Tackling air pollution is a complex issue which requires cooperation and coordination among multiple stakeholders from individual households to industries, farmers, NGOs, transport sector, power plants, waste collectors, construction firms, architects, and government agencies. The following measures can be taken to tackle the problem of air pollution:

• There is need for development of cycling infrastructure, use of bioethanol and CNG as fuel, and the construction of peripherals to tackle congestion.
• Incentives for increased adoption of Bharat Stage VI vehicles and fuel standards.
• Adopt alternative power sources including green and renewable resources.
• Use Green Building technologies and the application of green infrastructure and materials during construction.
• Moving highly polluting industries to the outskirts of cities. Online monitoring of waste discharges through polluting industries and increased monitoring in highly polluting industries.
• Door-to-door collection of segregated wastes.
• Incentivising farmers to adopt Happy Seeder and PUSA Decomposer, which reduce post-harvest residue.
• Emission trading can be applied in urban cities where economic incentives are offered to reduce the pollutant concentrations.