Why in news?

According to a study recently published in Lancet Planet Health, no one in India lives in areas where the yearly average pollution levels are below the levels recommended by the World Health Organization (WHO).

What’s in today’s article?

• WHO’s revised air quality guidelines 2021
• India’s National Ambient Air Quality Standards (NAAQS)
• Key highlights of the study

WHO’s revised air quality guidelines 2021

• 
• About
  • In September 2021, WHO updated its air quality guidelines (AQGs) to reflect the serious health impacts of air pollution: 
    • PM2. 5: The annual mean concentration should not exceed 5 µg/m3. This is half of the 2005 guideline of 10 µg/m3. 
    • NO2: The annual mean concentration should not exceed 10 µg/m3. 
    • Ozone: The peak season mean 8-hour concentration should not exceed 60 µg/m3. 
    • PM10: The annual mean concentration should not exceed 15 µg/m3, and the 24-hour mean should not exceed 45 µg/m3. 
    • SO2: The 24-hour mean concentration should not exceed 40 µg/m3. 
    • CO: The 24-hour mean concentration should not exceed 7 µg/m3. 
• Non-binding in nature
  • The WHO AQGs are not legally binding, but they are often used by countries and legislative bodies to set air quality policies. 
  • The guidelines are based on scientific evidence from multiple countries and are intended to help reduce the health impacts of air pollution.

India’s National Ambient Air Quality Standards (NAAQS)

• Ambient air quality refers to the condition or quality of air surrounding us in the outdoors.
• Under the authority of the Air (Prevention and Control of Pollution) Act of 1981, India’s Central Pollution Control Board sets national ambient air quality standards.
• The current Standards include following 12 pollutants:
• 

Key highlights of the study

• Widespread Air Pollution in India
  • No area in India meets the WHO's recommended PM2.5 pollution level of 5 µg/m³.
  • 81.9% of the population lives in areas exceeding India's National Ambient Air Quality Standards (NAAQS) of 40 µg/m³.
• Health Impact of Air Pollution
  • High levels of PM2.5 are linked to 1.5 million deaths annually in India.
  • Long-term exposure to air pollution increases risks of respiratory diseases, heart attacks, strokes, high blood pressure, and developmental delays in children.
  • Every 10 µg/m³ increase in PM2.5 levels raises the risk of death by 8.6%.
• Regional Pollution Levels
  • Pollution levels ranged from 11.2 µg/m³ in Arunachal Pradesh’s Lower Subansiri district (2019) to 119 µg/m³ in Ghaziabad and Delhi (2016).
• Potential for Improvement
  • Meeting NAAQS could prevent 0.3 million deaths annually; achieving WHO levels would save even more lives.
  • Identifying and addressing pollution sources, such as construction, vehicular emissions, and crop burning, is critical.