In Pics: List of 10 most polluted cities in the world; Delhi, Kolkata on top

• State of Global Affairs report provides an overview of air pollution levels and associated health impacts in cities around the world
• As urban areas are often hotspots for poor air quality, city-level data can help to inform targeted efforts to curb urban air pollution and improve public health

1/11State of Global Air report on air quality and health in cities, New Delhi and Kolkata are two of the world's top ten most polluted cities in terms of average annual population-weighted PM 2.5 exposure. (HT)

2/11Delhi recorded an annual average PM2.5 concentration of 110 micrograms per cubic meter in 2019. The city tops the world with the worst level of air pollution. NO2 pollution is universally high in populous cities across regions and highlights different hotspots than hotspots of fine particle pollution. (HT)

3/11Kolkata recorded an annual average PM2.5 concentration of 84 micrograms per cubic metre. The city rank second in the world with very poor air quality. The burden on health of PM2.5 has grown rapidly in cities in Southeast Asia. Of 7,239 cities analyzed, all the 20 cities with the largest increase in PM2.5-attributable death rates from 2010 to 2019 are located in Southeast Asia (HT)

4/11Kano, Nigeria is the third city in the list as it recorded an annual average PM2.5 concentration of 83.6 micrograms per cubic metre. Air pollution has been linked to an increase in hospitalizations, disability, and premature death from respiratory diseases, heart disease, stroke, lung cancer, diabetes, and communicable diseases such as pneumonia. (AP)

5/11Lima, Peru recorded an annual average PM2.5 concentration of 73.2 micrograms per cubic metre. Mayors from more than 45 cities around the world have signed the C40 Clean Air Accelerator, making a commitment to provide healthy air for everyone and implement substantive clean air policies by 2025. (Mint)

6/11Dhaka, Bangladesh recorded an annual average PM2.5 concentration of 71.4 micrograms per cubic metre. Cities are at the front line for air pollution impacts and interventions. Thoughtful interventions and investments to improve air quality can bring significant health and economic dividends. (HT)

7/11Jakarta, Indonesia recorded an annual average PM2.5 concentration of 67.3 micrograms per cubic metre. Exposures are particularly high in cities in Asia, West Sub-Saharan Africa, and Andean and Central Latin America. (Mint)

8/11Lagos, Nigeria recorded an annual average PM2.5 concentration of 66.9 micrograms per cubic metre. India is home to 18 of the 20 cities with the most severe increase in PM2.5 pollution from 2010 to 2019.  (HT)

9/11Karachi, Pakistan recorded an annual average PM2.5 concentration of 63.6 micrograms per cubic metre. The sources of air pollution vary across regions, countries, and even within cities. Common sources in cities around the world include fossil fuel–based energy generation, industrial activities, and transportation (AFP)

10/11Beijing, China recorded an annual average PM2.5 concentration of 55 micrograms per cubic metre. Dominant sources of PM2.5 are in a given location often depends on the local environment, household practices, and agricultural and industrial activities that occur in the vicinity.

11/11Accra, Ghana is on the 10th position in the list with average PM 2.5 concertation of 36.02 per cubic metre. Long-term exposure to PM2.5 pollution is associated with illness and early death from a variety of diseases including ischemic heart disease, lung cancer, COPD, lower respiratory infections (REUTERS)