World Air Quality Report 2021

In News 

  • The 2021 World Air Quality Report was released, the report presented an overview of the state of global air quality in 2021.

About

  • IQAir, a Swiss group that measures air quality levels based on the concentration of Particulate Matter (PM) 2.5.
  • IQAir endeavours to engage, educate, and inspire governments, researchers, Non-Government Organisations, companies, and citizens to work together to improve air quality and create healthier communities and cities.

Key Finding

 

  • In 2021, Mumbai had recorded Particulate Matter (PM) 2.5 annual average of 46.4 microgram/cubic metre – nearly nine times above the World Health Organisation (WHO) limit – according to a report by IQAir.
  • In 2021, 48 per cent of India’s cities exceeded 50 µg/m3, or more than 10 times the WHO guideline. 
  • India was home to 14 of the world’s 20 most polluted cities.
  • India’s PM 2.5 annual average reached 58.1 µg/m3 in 2021, ending a three-year trend of improving air quality. 
    • The country’s PM 2.5 annual averages have now returned to pre-quarantine levels of 2019.
  • New Delhi city is topping the list for the fourth consecutive year. Delhi topped a list of 92 capital cities in 2020, 85 such cities in 2019, and 62 such cities in 2018.
  • On the list of capital cities, Dhaka followed Delhi in terms of the annual average PM2.5 concentration.
  • Not a single country managed to meet the WHO’s air quality standard in 2021.

Risks of Air Pollution

  • Air pollution causes and aggravates many diseases, ranging from asthma to cancer, lung illnesses and heart disease.
  • The estimated daily economic cost of air pollution has been figured at $8 billion (USD), or 3 to 4 percent of the gross world product

What is Particulate Matter(PM?

  • Particulate matter (PM) are inhalable and respirable particles composed of sulphate, nitrates, ammonia, sodium chloride, black carbon, mineral dust and water.
  • PM2.5:
    • PM2.5 concentrations, in micrograms per cubic metre (µg/m³) were selected as the standard metric for this report. 
    • PM2.5, particulate matter consisting of fine aerosol particles measuring 2.5 microns or smaller in diameter, is one of six routinely measured criteria air pollutants .
    • It is commonly accepted as the most harmful to human health due to its prevalence in the environment and broad range of health effects.
    • It is generated from many sources and can vary in chemical composition and physical characteristics. 
    • Common chemical constituents of PM2.5 include sulphates, nitrates, black carbon, and ammonium. 
    • The most common human-made sources include internal combustion engines, power generation, industrial processes, agricultural processes, construction, and residential wood and coal burning. The most common natural sources for PM2.5 are dust storms, sandstorms, and wildfires.

Source:IE