Out of the world’s 100 most polluted cities, 94 are in India, China, and Pakistan

Every year, a thick smog covers India’s capital New Delhi. Last week, it got so bad for the 20 million residents that authorities shut schools.New Delhi’s concentration of PM2.5 particles, which damage people’s lungs, is 34 times the World Health Organization’s (WHO) acceptable levels. The toxic haze is especially bad during the winter as farmers burn stubble left in their fields.In 2020, India