Of the tested motorcycles, 77.8% failed to maintain standards, while 84% diesel driven buses and 69% of the trucks failed to meet emission standards
Among vehicles, buses, trucks, and motorcycles, are the main culprits for worsening air quality, according to a report.
The Department of Environment (DoE) carried out a study titled “Sources of Air Pollution in Bangladesh” under its “Clean Air and Sustainable Environment” project, in March last year.
During the study conducted to find out about emissions, 1317 vehicles were tested at several spots in Dhaka. 815 of them were CNG/gasoline vehicles and 502 were diesel vehicles. Among those, 158 diesel-run buses, 141 diesel-run trucks, and 203 diesel-run light vehicles were tested. Around 243 motorcycles were also tested.
Of the tested motorcycles, 77.8% failed to maintain standards, while 84% diesel driven buses and 69% of the trucks failed to meet emission standards. Around 59% of light vehicles including SUVs, Lagunas, mini trucks, maxis, microbuses, minivans, pickup trucks, and human haulers also failed to meet standards, said the report.
The deterioration of the capital's air quality for the last couple of years compelled the DoE authorities to conduct the study, Ziaul Haque, director (air quality management) of DoE, told Dhaka Tribune.
Dhaka had an Air Quality Index (AQI) score of 205 at 08:26am yesterday. The air was classified as "very unhealthy."
However, the report revealed that some 24% of the motorcycles emitted Hydrocarbons (HC) greater than 5000ppm that is considered very high. About 36.5% of these vehicles emitted carbon monoxide (CO) concentrations greater than 7.0% (v), which is also considered to be very high.
But the good news is that CNG run vehicles performed well compared to diesel run vehicles.
The government has set a standard level of carbon monoxide emissions from motorcycles at 4.5%(v), and 1200 parts per million is set for hydrocarbon emissions. Smoke opacity of 65 HSU was set as the standard for naturally aspirated diesel vehicles and 72 HSU for turbo charged diesel vehicles. The standard unit of carbon monoxide emissions was set at 3% (v) for CNG-driven three wheelers.
What experts, stakeholders say
Vehicles have become a big source of air pollution nowadays, said experts.
DoE Director Ziaul Haque said: “Our department is conducting mobile courts to identify the vehicles which emit the most. DoE is also making people aware of the adverse effects of air pollution.
“A comprehensive big project is needed to reduce emissions from vehicles as well as other sources,” he said.
Asked, Abdur Razzak, deputy director (enforcement) of Bangladesh Road Transport Authority (BRTA), said: “Motorcycles need to get fitness certificates with registration. And there is no legal provision to recheck the fitness of a motorcycle after five or ten years.
“Concerned officials also have to be more careful when they issue fitness certificates for buses and trucks. If they do so, pollution will be reduced.
“But there is a problem that we check fitness manually and do not have any emission measuring devices,” he said.
Dr Ahmad Kamruzzaman Majumder, chairman of the Department of Environmental Science at Stamford University, said: “We are using euro-2 engines. Most countries have stopped using it. We also use substandard fuel. Moreover, half of our vehicles do not have fitness.
“Brick fields are considered responsible for more than half of air pollution. But now it seems that emissions from vehicles are a bigger source.
“At the earliest we have to ban those vehicles,” he said.
The latest source apportionment study by the Norwegian Institute for Air Research (NILU) under the CASE project attributed about 10.4% of fine particles in Dhaka city to vehicular emissions and 7.7% to road dust.
Action taken by the authorities
The number of mobile court drives against unfit vehicles dropped to 35 in FY18 from 61 in FY17, a 42% decrease. The DoE collected Tk3.2 lakh in fines from vehicle owners in FY18, as compared to Tk4.65 lakh in FY17.
In line with the fewer number of mobile court drives conducted by the department of environment, the number of cases filed against owners of polluting vehicles also saw a decrease in FY18. The DoE filed 119 cases against owners of polluting vehicles in FY18, as compared to 279 filed in the previous fiscal.
According to the BRTA website, it operated 642 mobile courts from September 2019 to January 2020. These courts filed 4612 cases, sent 65 persons to jail, and fined Tk9,031,500 for violations, especially on fitness issues directly related to pollution.
Number of vehicles
According to BRTA, the number of registered motorcycles in Dhaka was 495,000 in July 2018, while it was only 210,000 in 2010. The number has risen significantly since 2017 when ridesharing services like Uber and Pathao were introduced. About 132,000 motorcycles were registered between 2017 and July 2018 in Dhaka.
There are 619,654 vehicles with BRTA registration and the number was 369,677 in 2010. There has been a 67.6% increase in the last eight years.
However, the BRTA submitted a report to a High Court bench recently, saying that only 165,764 vehicles, out of 458,359, renewed their fitness certificates across the country.
As such, it would seem that 292,595 vehicles without valid fitness documents were running on the roads till December 30 last year.