Air pollution: Vehicle smoke responsible for 50pc

Thick smoke emitted from the vehicles is mostly responsible for air pollution in the capital, a recent study has found.

According to a study by the chemistry department of Dhaka University, vehicles powered by fossil fuels make up 50 per cent of the contributors to air pollution.

The source of around 40 per cent of air pollution is burning straw, firewood, husks and small particles.

Burning coal in the brick kilns causes the remaining 10 per cent of air pollution.

The survey reveals the major source of air pollution in the capital has drastically changed.

For a decade, brick kilns were considered the main source of air pollution in the capital.

But the latest survey said smoke emitted from the vehicles and industries has overtaken the brick kilns.

Black carbon generated from small particles in the air is very harmful for human body, according to the survey led by DU chemistry department teacher and air quality observation centre chief Abdus Salam.

This black carbon floats in the air in most of the areas of the country including Dhaka over half of the year.

A huge amount of dust is being generated due to infrastructure construction and repair work in the big cities including Dhaka. Black carbon mixed with dust is spreading over the open spaces and houses. As a result, black carbon is entering the human body when a person breathes, even indoors.

Speaking to Prothom Alo, professor Abdus Salam said it is a good initiative that the government is demolishing illegal brick kilns.

But date-expired vehicles are contributing majorly to air pollution, he said adding strong measures are not being taken against these vehicles.

Construction of big infrastructure is taking place, but there are no visible steps to control dust, Abdus Salam pointed out.

On the streets buses are emitting black smoke leaving every one's face blackened. Even members of traffic police are affected by this. But no step is seen to be taken. All smoke emitted from the vehicles is responsible for pollution. Black smoke causes pollution mostly. Date-expired vehicles are the major source of black smoke.

According to government organisation Bangladesh Road Transport Authority (BRTA), the number of date-expired vehicles are around 500,000 and from which black smoke are emitted. Such vehicles are increasing by 20 to 30 per cent every year.

As per statistics of 2020, the registered motorised vehicles are 4,558,878. Of them, a total of 16,30,036 vehicles are in the capital.

In September last year, US Chemical Society revealed research findings on the source of black carbon in South Asia. The research was conducted by eight teachers of Dhaka University, Norwegian Institute of Air Research and Stockholm University.

According to the findings, black carbon is the major cause for air pollution in South Asia. Some 52 per cent of black carbon comes from the smoke emitted from vehicles for burning fuel.

According to world air quality observation agency, Air Visual, the air quality deteriorated by 12 per cent in 2020 than that of 2019.

Under the fresh air project of the environment department, a survey was conducted on the source of air pollution in the capital in 2012.

It said brick kilns are responsible for 58 per cent of air pollution in the capital. Dust and smoke are responsible for some 25 per cent, some seven 7 per cent for burning fuel. The remaining sources are industries and others.

On the basis of the findings, the environment department mostly conducted operations against the brick kilns across the country.

According to statistics of 2020 of the environment department, there are around 33,800 brick kilns across the country. Of them, some 7,000 brick kilns have adopted environment-friendly technologies. Some 2,513 brick kilns have no clearance from the environment department.

The environment department conducted operations against about 2000 brick kilns in last two years. Of them, some 1000 brick kilns were demolished. A total of Tk 450 million have been fined.

The environment department said the amount of transforming brick kilns into environment-friendly ones by adopting technologies has increased after the operation.

"Sources of air pollution other than the brick kilns are increasing. We will strengthen the operation against the date-expired vehicles and the dust from construction work.," said Ruhina Ferdousi, director of enforcement wing of the environment department.

Speaking to Prothom, BRAC University emeritus professor Ainun Nishat said, "The government should take steps to stop all sources of air pollution. There are no visible steps against sources other than brick kilns."

*This report, originally published in Prothom Alo print and online edition, has been rewritten in English by Rabiul Islam.