According to a report prepared by British company HouseFresh, Bangladesh was the most polluted country across the world in 2020, followed by Pakistan, India and Mongolia. Ghaziabad in Uttar Pradesh took the second spot on the list of polluted city with an average PM2.5 concentration of 106.6µg/m3 after China's Hotan in Xinjiang province. PM2.5 refers to fine particulate matter suspended in the air that is two and a half microns or less in width.
In the case of Ghaziabad, the report says massive traffic volumes in the “gateway” to Uttar Pradesh were likely the cause of the high levels of air pollution while that in China’s Hotan, with a PM2.5 of 110.2µg/m3, was largely attributed to local sandstorms given its proximity to the Taklimakan Desert, the world’s largest shifting sand desert.
Bangladesh’s Manikganj is in the third position on the list of the world’s most polluted cities with a PM2.5 of 80.2µg/m3.
The author states, “As one of the fastest developing countries around the world, with its industrial sector growing at a rate of 13% per year, vehicles and industrial emissions are the major contributors to air pollution in this country of 165 million people."
Of the 50 most polluted cities worldwide, 49 are in Bangladesh, China, Pakistan, and India. The report on the world's best and worst places for clean air in 2020 was prepared based on the average value of PM2.5 concentration in µg/m³ by collecting data from Swiss air quality expert IQAir.
The Tasmanian city of Judbury in Australia topped the list of cities with the cleanest air with a PM2.5 level of 2.4µg/m3. Kailua Kona in Hawaii, US, and Muonio in Finland were the next best places in 2020 for clean air, with PM2.5 concentrations of 2.6µg/m3 and 2.8µg/m3 respectively.
