IQAir’s 2021 report: Mumbai’s pollution level 9 times above WHO limit

What is the News?

The 2021 World Air Quality Report has been released.

What is the World Air Quality Report 2021?

Released by: IQAir, a Swiss organization

Purpose: The report is based on Particulate Matter (PM) 2.5 air quality data from 6,475 cities in 117 countries, regions, and territories around the world.

What are the key findings of the report related to India?

For the fourth consecutive year, Delhi has been named the most polluted capital in the world, with pollution rising almost 15% over 2020.

35 of the 50 cities with the worst air quality are in India. Among these cities, Rajasthan’s Bhiwadi tops the list, followed closely by Uttar Pradesh’s Ghaziabad.

Mumbai had recorded a PM 2.5 annual average of 46.4 microgram/cubic metre – nearly nine times above the World Health Organization (WHO) limit.

48% of Indian cities exceeded 50 μg/m3 air quality level, which is well over 10 times the WHO guidelines.

Note: WHO’s guidelines of September 2021 warrant good air quality with a PM2.5 concentration level between 0-5 g/m3.

What is the significance of the report?

Air pollution is now considered to be the world’s largest environmental health threat, accounting for seven million deaths around the world every year. 

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% of the gross world product.

Why does the report measure PM 2.5?

PM2.5, particulate matter consisting of fine aerosol particles measuring 2.5 microns or smaller in diameter, is commonly accepted as the most harmful to human health due to its prevalence in the environment and a broad range of health effects.

In 2021, the deaths of 40,000 children under the age of five were directly linked to PM2.5 air pollution.

PM2.5 is generated from many sources and can vary in chemical composition and physical characteristics. Common chemical constituents of PM2.5 include sulfates, 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: This post is based on an article “IQAir’s 2021 report: Mumbai’s pollution level 9 times above WHO limit” published in Indian Express on 25th March 2022