According to the 6th Annual World Air Quality Report, Begusarai has emerged as the most polluted metropolitan area globally in 2023.

Key findings in the report

India is among the world's top three most polluted countries in 2023, according to the 6th Annual World Air Quality Report released by IQAir..
IQAir uses data from both government sources, such as air-quality data from regulatory bodies like the US Environmental Protection Agency, and lower-cost sensors like the ones it produces. While regulatory monitors can be expensive, IQAir and similar sensors cost only a few hundred dollars.
The report analyzed data from over 30,000 air quality monitoring stations worldwide and indicates a concerning situation for India's environment and public health. The report says India's average PM2.5 concentration is more than ten times the World Health Organization's (WHO) annual guideline, ranking India behind only Bangladesh and Pakistan in the list of the most polluted countries.
The report indicates that 83 of the 100 worst polluted cities in the world are in India, and Central & South Asia accounted for the ten most polluted cities on the planet. The report urges collaborative efforts to address transboundary haze and other pollution sources that exacerbate the situation.

Only ten countries and territories had "healthy" air quality levels

The report found that only ten countries and territories had "healthy" air quality levels, namely Finland, Estonia, Puerto Rico, Australia, New Zealand, Bermuda, Grenada, Iceland, Mauritius, and French Polynesia.

9% of global cities and only 10 countries had air quality that met World Health Organization guidelines for harmful fine-particle or PM2.5 pollution.

Most affected

The report identified the Middle East, Africa, and Central and South Asia as some of the places most affected by air pollution.
The five countries with the most polluted air in 2023, weighted by population, were Bangladesh, Pakistan, India, Tajikistan, and Burkina Faso.
The report also revealed that fossil fuels, such as coal, oil, and gas, contribute significantly to outdoor air pollution, which is responsible for the early deaths of over 4 million people worldwide each year.

About PM2.5

PM2.5 is a mix of gases and particles that float in the air and are classified by their size. It's called particulate matter, with "2.5" referring to the size of the particles, which are 2.5 microns, or 1/30th the width of a strand of hair. The tiny size of PM2.5 is what makes it so dangerous.
These particles are small enough to enter various organs and the bloodstream, and can irritate the respiratory system and lungs.
This can cause health problems. For example, PM2.5 pollution has been linked to heart attacks and strokes, and can cause oxidative stress.
This is when the body's cells are damaged faster than they can repair themselves. Oxidative stress has been linked to many illnesses, including Parkinson's disease and cancer.
Recent studies have also shown that PM2.5 can affect brain development, which is a concern for young children.
That's why in 2021, the World Health Organization recommended that the average concentration of PM2.5 in the air should be lowered from 10 micrograms per cubic meter to 5 micrograms per cubic meter. However, very few countries have met this target.

About IQAir

IQAir is a Swiss technology company that helps to improve air quality through information, collaboration, and intervention.