Delhi shuts schools as pollution surges to season's worst levels

No quick respite in sight for residents amid unfavourable weather conditions

- Debarshi Dasgupta

Schools were shut on Nov18 onwards and offices advised to operate at half capacity as pollution levels in India's capital and surrounding areas surged to their worst levels this winter - continuing a grim annual trend as cold and calm weather sets in and traps pollutants from various sources.

The Air Quality Index (AQI) in Delhi hit 494 on the afternoon of Nov 18, the worst such reading for November in recent years. AQI values can range from "Good" (0-50) to "Severe Jr" (451-500).

The same day, PM2.5 levels in the city crossed 410 micrograms per cubic metre of air (mcg/cubic m), more than 25 times the 24-hour safe limit prescribed by the World Health Organisation. Fine particulate matter (PM2.5) can penetrate the lungs, causing cardiovascular and respiratory diseases.

"We are now mentally prepared that each year schools are going to shut down for a pollution break after Diwali and classes will move online," said Ms Anju Sharma, a 40-year-old housewife living in Delhi, whose nine-year-old twins have been attending lessons online since Nov 14.

Schools in the city are now shut "until further orders" and the Sharmas' children have been allowed to play only indoors since last week, when pollution levels started worsening. Yet, the twins have been complaining of breathlessness, said their mother.

Delhi's major year-round sources of pollution include vehicular emissions and dust from construction activities. Solid waste burning and the use of dirty fuels in poorly monitored and illegal industries in the city are other key sources, besides the use of wood as a cooking fuel by its urban poor.

This cocktail of emissions worsens each year at the onset of winter, due to the use of firecrackers during Diwali and by emissions from stubble burning as farmers clear harvested padi fields for wheat season.