On Nov 1, 2019, the residents of New Delhi and the surrounding towns in the National Capital Region woke up to a thick blanket of smog, with sunlight barely reaching the ground. People were coughing, had teary eyes, and reported headaches. At noon, the Air Quality Index (AQI) was hovering around 530—more than ten times the safe value of 50. An AQI above 500 is categorised as “severe plus” or “emergency” level. The levels of particulate matter (PM) pollutants PM10 and PM2·5 had reached 500 μg/m³ and 300 μg/m³, respectively, five times above what is considered “good” air quality.

Within hours, the Environment Pollution (Prevention & Control) Authority of the National Capital Region declared that “this is a public health emergency as air pollution is now hazardous and will have adverse health impacts on all”. The authority advised people to “minimise personal exposure as far as possible and not to exercise in the open” and to reduce exposure of children, the elderly, and vulnerable people. The state gov ernment ordered the closure of schools and enforced a road rationing plan to cut emissions from motor vehicles, besides ceasing all construction activity.

Read the entire report here:  Lancet – air pollution