human
What is the most polluted city in the world?
assistant
The answer to this question will depend on your definition of “pollution”. According to the World Health Organization, air pollution is a major health risk and causes more than 3 million premature deaths every year. In terms of cities, the most polluted city in the world is probably Delhi, India, which has an annual average PM2.5 concentration of 153 micrograms per cubic meter.