Vehicle smoke, road dust add to winter air pollution in Delhi

Apart from stubble burning by neighbouring states, Delhi has to battle pollution from millions of vehicles, construction and road dust.

Apart from stubble burning by neighbouring states, the Capital has to battle pollution from millions of vehicles, construction and road dust.

In winter, vehicles contribute 25% to PM2.5 which could be above 35% at some places, according to a study conducted by IIT Kanpur.(Raj K Raj /HT FILE)

The problem becomes graver during winters. “With winter approaching, Delhi and other parts of north India show a noticeable spike in air pollution,” said Centre for Science and Environment (CSE) executive director Anumita Roychowdhury.

She said Delhi also suffers from the lacklustre attitude of its own authorities and people. “Others (contributors of pollution) are industrial waste and diesel trucks and interstate buses entering the city.”

A study conducted by IIT Kanpur on Delhi’s pollution levels says that emissions from vehicles are the second largest source of particulate matter, especially PM2.5. Construction dust and stubble burning are the other sources.

Vehicular pollution grew from 64% to 72% between 1990 and 2000, the report says. In winter, vehicles contribute 25% to PM2.5. At places, it could be above 35%. It also says that diesel vehicles contribute significantly to PM10 and PM2.5.

Delhi has over 8.9 million registered vehicles. In addition, 570,000 personal and passenger vehicles enter Delhi every day, shows a CSE study in June.

In comparison, a total of 569,000 vehicles were registered in the city in 2014-15, according to the Economic Survey of Delhi. This shows that the number of vehicles coming into Delhi daily is almost equal to the number registered in the city in a year.

“The number of vehicles on the roads is increasing every day, but the space is the same. So, vehicles crawl on the road. With lower speed, engine efficiency reduces and emission levels increase,” said senior principal scientist at CSIR-Central Road Research Institute (CRRI), Dr S Velmurugan.

The city’s average speed has gone down from 20 kilometres an hour to 5 kilometres an hour over five years, he said quoting studies by CSIR-CRRI.

Read: Delhi chokes on smoke from neighbouring states

ROAD AND CONSTRUCTION DUST

The daily PM10 and PM2.5 emissions from road dust are 79,626 kilos and 22,165 kilos, respectively. Broken and poorly maintained roads, a regular sight in Delhi, also cause significant non-exhaust road dust emissions.

Also, construction dust contributes to 40% of the city’s total waste generated.

“The most harmful element in construction matter is silica which often escapes the human body’s filter mechanism. Over a period of time, it shrinks lung capacity and makes the person vulnerable to all kinds of infections,” said Dr Neeraj Jain, chest specialist at Ganga Ram Hospital.