Chad replaced Bangladesh as the country with the most polluted air in 2022.With the only real-time, publicly available source of air quality data for the entire country of Chad being provided by a single air quality monitor in the city of N’Djamena, the spotlight on global air quality data coverage disparities shines bright on the continent of Africa, according to the 2022 World Air Quality Report.N’Djamena, the capital of Chad, ranked number one as the most polluted regional city with an annual average PM2.5 concentration of 89.7 µg/m3, a 12 percent increase from 2021, the report said.In 2022, Bangladesh ranked fifth in the overall rankings with 65.8 points. Read More: River pollution: Artists take to unique protest in Habiganj In some of the capital cities in the region (Dhaka, Bangladesh; Bishkek, Kyrgyzstan; Islamabad, Pakistan; Colombo, Sri Lanka) the percentage of low-cost sensor stations is more than 80 percent.Iraq, Pakistan and Bahrain held the second, third, and fourth positions in the AQI ranking for 2022 respectively with 80.1, 70.9 and 66.6 points.The top five most polluted cities in the world in 2022 were: N’Djamena, Chad (89.7); New Delhi, India (89.1); Baghdad, Iraq (86.7); Manama, Bahrain (66.6); and Dhaka, Bangladesh (65.8).The 2022 World Air Quality Report reviewed the state of global air quality in the year. The study contains statistics on PM2.5 air quality from 7,323 cities in 131 nations, regions, and territories. Read More: Govt committed to doing all it can to defeat pollution: Environment MinisterThis report's data was compiled from over 30,000 regulatory air quality monitoring stations and low-cost air quality sensors, the report said. Governing authorities, research institutes, non-profit non-governmental groups, universities and educational facilities, commercial corporations, and citizen scientists run these monitoring stations and sensors all around the world, said the report.The PM2.5 data in this report is measured in micrograms per cubic meter (g/m3) and uses the World Health Organization (WHO) air quality recommendations and interim objectives from 2021 as a basis for data visualization and risk communication. Read More: 6 vehicles, 5 institutions fined in anti-pollution drive in Dhaka