Data: How pollution moved from north to south

Pollution remained high in parts of Chennai on November 9, 2019  

Every winter, northern India sees high levels of pollution widely attributed to stubble burning. This year, the fumes drifted beyond that region to other parts of the country too.

In the first week of November, apart from the Delhi-NCR region, cities along the eastern coast of the country also registered high levels of PM2.5 (fine Particulate Matter which have a diameter of less than 2.5 µg/m3). Chennai, Kolkata, and Visakhapatnam were among cities which recorded high levels in this period.

Post Deepavali, pollution levels in Delhi NCR had reached alarming levels which led to closure of schools in the city for nearly a week. Dispersion models and independent weather experts had suggested that the plumes of smoke over Delhi were travelling east towards the Bay of Bengal and from there were blowing into parts of southern India.

Travelling south

The maps show the forecasted PM2.5 levels (particulate matter less than 2.5µg/m3 diameter) in India on October 31, November 3, November 6 and November 8 by the European Union Earth Observation Programme. The darker the blue, the higher the PM2.5 levels.

Central Pollution Control Board data shows that daily average PM2.5 levels dropped significantly over the first week of November in Delhi-NCR and parts of U.P. and Bihar. However, in the same period, the concentration rose and remained well above the permissible limit of 60µg/m3 in parts of West Bengal, Odisha, Andhra Pradesh, Karnataka and Tamil Nadu.

High pollution levels only in north India

image/svg+xml October 31

Pollution eases a little in the north as it spreads to the east

image/svg+xml November 3

Pollution eases a lot in the north while peaking in the south, east

image/svg+xml November 6

While the levels drop in the south, they remain high in the north