Photo : Messenger
Due to geographical reasons, air pollution in Dhaka increases every winter. However, this time around, the pollution in the capital's air has escalated long before the onset of winter, making it one of the most polluted cities in the world.
In the last three months, Dhaka has entered the list of the most polluted cities with an AQI score of more than 300, according to the air quality monitoring organization IQ Air. However, if a site has an AQI score between 301 and 400, it is considered 'risky.' Moreover, if this AQI score exceeds 300 for three consecutive hours, a health emergency can be declared.
According to the data, the AQI in Bangladesh is determined based on five pollution characteristics: Particulate Matter (PM10 and PM2.5), NO2, CO, SO2, and Ozone (O3). Dhaka has been grappling with air pollution for an extended period. The city's air quality typically becomes unhealthy during winter and improves slightly during monsoons.
A report by the Department of Environment and the World Bank in March 2019 identified the three main sources of air pollution in Dhaka as brick kilns, vehicle fumes, and dust from construction sites. However, environmentalists and researchers claim that Dhaka's air is excessively polluted due to road and building construction, smoke from brick kilns and factories, vehicle fumes, and open burning of waste.
Since November last year, Dhaka has been observed to be the world's most polluted city for one day out of every three days, with the air quality index above 330. Dhaka was ranked second in the list of cities with polluted air in the world on Wednesday morning. At 11:16 am, the air quality in the capital was 'hazardous' with an AQI score of 310.
According to previous years' patterns, air quality in Bangladesh is usually so poor from November to mid-March that around 65 percent of the year's air pollution occurs during those five months, environmentalists said. Experts have identified specific reasons behind Dhaka's repeated top spot in the pollution list, breaking all previous records.
Ahmad Kamruzzaman Majumdar, the dean of the Environmental Science Department at Stamford University Bangladesh and a climatologist, told The Daily Messenger, “Air pollution has increased by more than 10 percent this year compared to the last 8 years, which is a significant concern.”
Meanwhile, in the capital, construction of small and large buildings and road repair works is carried out throughout the year. Additionally, various big projects, including metro-rail and elevated expressways, have been added in the last few years. Although there are specific instructions from the Department of Environment to prevent air pollution during any construction work, in practice, it is not observed that they are being followed.
During the construction or repair of roads and buildings, there is a rule to provide appropriate temporary shelters or fences at the construction site so that the dust does not mix with the air. Also, proper covering of building materials (soil, sand, rods, cement, etc.) inside and outside the enclosure and sprinkling of water at least twice a day are mentioned. If anyone does not follow these rules in the construction of buildings and roads, the city corporation can blacklist the contractor as well as impose fines. However, these rules are often limited to being on paper.
Syeda Rizwana Hasan, Chief Executive of Bangladesh Environmental Lawyers Association (BELA), told The Daily Messenger, “We have many mega-projects centered on Dhaka. They contain guidelines for controlling air pollution when the environmental impact assessment report is approved and clearance is granted. But the Environment Department does not have the courage to go to the site and stop the work if they are not followed.”
According to the Air Pollution Survey 2021 conducted by CAPS, a pollution research institute, there are about 1,200 brick kilns and thousands of small and large industrial factories around Dhaka, contributing to pollution.
Experts note that many brick kilns in Bangladesh still operate in the traditional way, using coal and wood as fuel. This results in the production of a significant amount of ash and polluting particles such as carbon monoxide, sulfur oxides, and carbon dioxide, which mix with the air. An Act titled the ‘Brick Making and Kiln Installation (Regulation) Act, 2013 (Amended 2019)’ was passed to reduce air pollution, but unfortunately, the law is not enforced.
Over time, various types of industrial factories have been established in Bangladesh. According to the CAPS study, more than 50 percent of the nation’s air pollution comes from industries. A few decades ago, the air in this land was not as harmful to humans. However, with dust mixing with industrial chemicals, pollutants from brick kilns, and black carbon from burning petrol, the air is now identified as a significant source of pollution.
Md. Hadiuzzaman, Professor of the Civil Engineering Department at Bangladesh University of Engineering and Technology (BUET), told The Daily Messenger, “Around 2019-2020, 200-250 unauthorized brick kilns were closed. However, these brick kilns are now being set up again, leading to an increase in air pollution. Since brick kilns operate only in winter, monitoring them before winter was necessary. Those without modern facilities should have been closed before winter.”
“If you stand on any street in the city for a while, you will observe various unfit vehicles, especially buses and trucks, running loudly and covering the surroundings with black smoke,” he added.
Experts said that unfit vehicles continue to operate in the capital due to negligence by the Bangladesh Road Transport Authority and the traffic police.
Professor Hadiuzzaman also mentioned, “Seventy percent of the buses running in Dhaka city are at the end of their lifespan. When a vehicle reaches the end of its economic life, it cannot burn fuel properly and emits harmful chemicals along with its fumes. The authorities are not concerned about buses running without fitness in Dhaka.”
Another cause of air pollution in Dhaka is the open burning of waste. According to CAPS research, air pollution is increasing in areas where waste is burnt in Dhaka, producing methane gas in landfills.
Syeda Rizwana Hasan said, “Waste is burned in at least 50 places in Dhaka city during the dry season. I think the most neglected sector in our 52 years is the waste management sector. When the volume of garbage increases in Aminbazar landfills, we go and protest. But at night they set fires secretly.”
However, Saber Hossain Chowdhury, Minister of Environment, Forest and Climate Change, said that 500 illegal brick kilns around Dhaka will be removed as part of a 100-day programme to reduce air pollution. On Wednesday, he announced that fines would be increased if sand and cement are carried in Dhaka city by open trucks. The penalty amount for the construction of new buildings without covering will also be increased. Those responsible for air pollution will not be exempted in any way.
According to the World Health Organization (WHO), air pollution has increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections, causing an estimated 7 million deaths worldwide each year.
Messenger/Fardin
