Ground-level Ozone Pollution

General Studies Paper-3

Context: Delhi-NCR has topped the list of 10 cities for most days crossing ground-level ozone pollution levels.

About

• The analysis is based on granular, real-time data (15-minute averages) from the Central Pollution Control Board.
• The report analysed metropolitan areas of Bengaluru, Chennai, Kolkata, Mumbai and Pune.

Major Findings

• All 10 areas studied witnessed exceedances of the national ozone standard, with Delhi being the most affected.
• Ozone levels were elevated even at night, with Mumbai recording the most instances of night-time exceedances.
• The duration of ozone exposure is concerning, lasting an average of 12-15 hours across most cities, the researchers found.
• Summer is the peak season for ozone, the problem persists year-round in many areas, particularly in sunnier southern cities.
• Ozone accumulates not only in metropolitan areas but also travels long distances, creating a regional pollutant that demands both local and regional action.

Ground-Level Ozone (O3) Pollution

• There are two kinds of ozone:
  • High-altitude ozone or the “good ozone” that is high up in the atmosphere and forms a protective barrier around the Earth from the Sun’s harmful ultraviolet rays.
  • Ground-level ozone or the “bad” ozone that forms closer to the Earth in the air we breathe. This ozone is not usually emitted directly, but rather forms from chemical reactions between oxides of nitrogen (NOx ) and volatile organic compounds (VOCs) in sunlight. The term “ozone” is not to be confused with “smog,” another type of pollution that consists of ground-level ozone and other gaseous and particulate pollution.

Impact of Ozone

• Impact on human health: Breathing ground-level ozone can cause chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ozone also can reduce lung function and inflame the lining of the lungs.
• Impact on environment: Ozone damages vegetation and ecosystems by inhibiting the ability of plants to open the microscopic pores on their leaves to breathe.
  • It interferes with the photosynthesis process by reducing the amount of carbon dioxide the plants can process and release as oxygen.
• Impact on crops: The increase in ozone levels impacted agriculture globally, with ozone-induced crop losses averaging 4.4 percent–12.4 percent for staples.
  • Losses for wheat and soybean were as high as 15 percent-30 percent in key agricultural areas of India and China.

Air Pollution

• When harmful substances (pollutants) – particles, gases, or matter – are released into the air and reduce its quality, the air is polluted.
• Common air pollutants include: Particulate Matter (PM), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), Ozone (O3), Carbon Monoxide (CO), Volatile Organic Compounds (VOCs), Lead etc.
• Source: These pollutants can originate from natural sources such as volcanic eruptions and wildfires, but human activities such as industrial production, transportation, agriculture, and residential heating are significant contributors to air pollution.

Steps Taken by Government of India to combat Air Pollution

• National Clean Air Programme (NCAP): Launched in 2019, NCAP is a comprehensive initiative with the goal of reducing air pollution in identified cities and regions across India.
  • The program focuses on improving air quality monitoring, implementing stricter emission standards, and promoting public awareness.
• Bharat Stage VI (BS-VI) Emission Standards: The government implemented BS-VI emission standards for vehicles nationwide in 2020.
  • These standards aim to reduce vehicular emissions by mandating the use of cleaner fuel and more advanced emission control technologies.
• Pradhan Mantri Ujjwala Yojana (PMUY): The PMUY scheme aims to provide clean cooking fuel to households by promoting the use of liquefied petroleum gas (LPG) as an alternative to traditional biomass-based cooking methods.
• FAME (Faster Adoption and Manufacturing of Hybrid and Electric Vehicles) Scheme: The FAME scheme promotes the adoption of electric and hybrid vehicles to reduce air pollution caused by vehicular emissions.
  • Incentives are provided to both manufacturers and consumers to encourage the use of electric vehicles.
• Green Initiatives for Sustainable Habitat (GRIHA): GRIHA is an initiative to promote sustainable and environmentally friendly practices in the construction and operation of buildings.
  • It encourages the use of energy-efficient technologies and materials to reduce pollution.
• Waste Management Programs: Proper waste management is crucial to prevent the burning of waste, which contributes to air pollution.
  • Various waste management initiatives, including the Swachh Bharat Abhiyan, aim to address solid waste issues and promote cleaner disposal methods.
• Commission for Air Quality Management: The Commission has been set up for Air Quality Management in the National Capital Region and Adjoining Areas for better coordination, research, identification, and resolution of problems surrounding the air quality index.

Way Ahead

• Insufficient monitoring, limited data, and ineffective trend analysis methods have hampered understanding of this growing public health risk.
• The complex chemistry of ground-level ozone makes it a difficult pollutant to track and mitigate.
• Stringent regulations are needed to curb nitrogen oxide emissions from vehicles, industries and other sources.

There is a need for a multi-pronged approach to air pollution control in India.