India has been ranked at 8th spot in the most polluted countries around the world, according to a report released by Swiss firm IQAir on Tuesday. However, India improved its ranking as it dropped from 5th to 8th place, the report said.

The report named 'World Air Quality Report' 2022, presented PM2.5 air quality data of 7,300 cities across 131 countries. It ranked world's top 10 most polluted countries on the basis of the average recorded annual PM2.5 concentration in micrograms per cubic metre (μg/m3).

According to the report, 39 of 50 most polluted cities in the world are in India. Delhi ranked 4th in the top 50 most polluted cities in the world. Its PM2.5 level is almost 20 times the safe limit, the report stated. Meanwhile, NCR regions including Noida, Ghaziabad, Gurugram and Faridabad have seen a decline in pollution levels.

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India's annual average PM 2.5 level in 2022 was 53.3 ug/m, only slightly lower than the 2021 average of 58.1. In 2021, 12 of the 15 most polluted cities in the Central and South Asia was in India. That number stayed the same in 2022, the report said.

There are six Indian cities in the top 10, 14 in the top 20, 39 in the top 50, and 65 in the top 100, up from 61 in the previous year. Delhi and New Delhi are both in the top 10, based on a new classification.

Among the six metro cities, Kolkata was ranked the most polluted after Delhi. However, Chennai was stated to be the cleanest with pollution 'just' 5x the WHO's safe level. The metro cities -- Hyderabad and Bengalurua -- saw pollution levels uptick over the average since 2017, the report said.

Bhiwadi in Rajasthan retained its position as the most polluted city in the country. It saw annual PM2.5 levels of 92.7 ugim. Roughly 60 percent of cities in India included in the report experienced annual PM2.5 levels of at least seven times higher than the WHO guideline, the report said.

Chad, Iraq, Pakistan, Bahrain, Bangladesh, Burkina Faso, Kuwait, India, Egypt and Tajikistan were the top 10 most polluted countries while Australia, Estonia, Finland, Grenada, Iceland, and New Zealand met the World Health Organization (WHO) PM2.5 guideline (annual average of 5 Aug/m3 or less), as per the report.

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