Indian capital resumes some activities despite hazardous air, river foam

MUMBAI – India’s capital reopened schools and some building sites on Nov 20, amid signs of receding air pollution that the authorities had deemed hazardous, although a toxic foam contaminated stretches of the Yamuna river flowing through New Delhi.

The world’s most polluted capital resumed its annual battle on pollution in November, despite government pledges to improve.

On Nov 20, the air quality index (AQI) of 336 was down from Nov 16’s level of 509, but still “hazardous”, Swiss group IQAir said.

Children wore masks on the way to school, after a closure of nearly two weeks to protect them from pollution.

Hindu devotees celebrating a festival trudged through the smoggy morning for a dip in the river, undeterred by the white foam, which the authorities have described as toxic.

The foam arises from settled sludge and untreated waste, said a former adviser to the Delhi government, adding that the city’s water board was spraying a food-grade chemical to control it. 

“The foam is not lethal by nature,” said the former official, environmental engineer Ankit Srivastava. “You will not die by consuming it, but you would fall ill.” 

On Nov 19, Delhi Environment Minister Gopal Rai told reporters that construction work on public infrastructure projects could resume, although with curbs on activities that blow dust through the air.

Those remarks followed Nov 18’s revocation of emergency measures ordered on Nov 5 to keep air quality from worsening, including a ban on all building activity. But they were eased after index levels improved.

Delhi’s air pollution gets worse in winter, when wind speeds drop and cooling air traps pollutants spewed by vehicles, industry and farmers burning agricultural waste in surrounding states to prepare for new planting.

Delhi’s AQI is forecast to fall over the next two days as wind speeds are expected to pick up, according to the government’s early warning system for air quality.

Traffic emissions were a big contributor on Nov 20 to PM2.5 particles suspended in the air, a real-time study by experts collaborating with the Delhi government showed.

Vehicles contributed 51 per cent of such particles, considered especially dangerous to humans, along a key thoroughfare, up from levels of 27 per cent and 32 per cent over the past two days, the study added.

PM2.5 levels have remained above 128 micrograms per cubic m of air since Nov 19 in the National Capital Region, according to the federal pollution control board.

The levels have fallen from a high of 300 on Nov 5, but are substantially above the average 24-hour safe limit of 15 set by the World Health Organisation. REUTERS