On February 6, 2021, smoke emanated from the kiln in a brick building in the outskirts of Dhaka, Bangladesh. Ahmed Salahuddin/Nurphoto by Getty Images/Nurphoto Closed subtitles
During the dry winter in Bangladesh, thousands of workers shovel millions of tons of coal into kilns across the country. As hand-packed bricks bake and harden, dark smoke poured out over 8,000 chimneys that marked the skylines in rural and urban areas.
“It’s a lot of black smoke that affects workers and nearby villagers, and the overall air quality in the area.” Sameer MaithelHe is an engineer at Greentech Knowledge Solutions, a consulting firm in Delhi, India.
Bangladesh's air is always the most polluted air on the planet. The brick kiln contributes 10% to 40% of the tiny particles that make up the contaminated. These particles can enter our lungs and even our blood, leading to health problems including respiratory illnesses, strokes and even cognitive problems.
But something as simple as stacking bricks might place one Major dents in this pollutionAccording to new research on more than 275 kilns published scientifically by Maithel and colleagues.
“This is great evidence of how simple low-cost interventions can have a significant impact on energy use,” said William Checkley, an epidemiologist at Johns Hopkins University. “If we can implement these, we could have a significant impact on energy use and emissions, thereby improving air quality throughout Southeast Asia.”
Bricks are the main foundation of Bangladesh. The densely populated and rapidly urbanized country produces nearly 30 million bricks per year, more than 90%, accounting for loose coal-fired furnaces.
“Building traditional style brick kilns is very simple and cheap, so they just surge.” Nina Brooksa global health researcher at Boston University.
The process is like this: First, the matte clay bricks are molded in wooden boxes and stacked to dry in the sun. Next, thousands of bricks were piled up in the shooting room and covered with ashes. The workers then shoot bricks, shovel up a large amount of coal, and bounce them away.
"These brick kilns are really low in combustion efficiency, which means they end up burning much more coal than they need, which is why they are so polluted here," Brooks said.
Each kiln can employ up to 200 workers. They are the most direct effects of smoke, a study found Nearly 80% report some kind of respiratory problem. But they are not the only ones. Kilns are usually close to densely populated areas, which adds to smoke from urban life.
The brickworker balanced the bricks on his head when he took them away from a kiln near Dhaka, Bangladesh. Zakir Hossain Chowdhury/Anadolu Agent/Getty Images/Anadolu Closed subtitles
Brooks said that despite regulations regarding the kilns can and cannot operate, they are not always followed. “We found that 77% of brick kilns are illegally located too close to the school.”
The pollution of modern high-tech kilns is greatly reduced, but it is 25 times more expensive to build and operate. "They haven't really taken off yet," Brooks said.
Instead, the solution the team is looking for will be easier and cheaper for the average brick producer.
During his decades of working with brick kiln owners in India, Maithel noticed suspicious practices.
He said many kiln operators fill the kilns with too many bricks. A tight spacing will clog the oxygen flow, which is required for effective combustion. This also means that the hot coals are stuck on the top of the stack instead of falling to the bottom, causing some bricks to be over-smeared while others are not shot.
He also noticed that workers often shovel coal in competitions, work hard on two or three teams, and then rest all. This leads to uneven refueling, which can also hinder efficiency.
As an energy systems engineer, Maithel knows that some simple changes can really help you. He said simply adding the brick stack in a zigzag pattern to increase airflow and ensure more consistent delivery of coal can help the kiln run more efficiently.
To see if this simple intervention can help reduce air pollution and increase profits, the team plans to conduct large-scale experiments in 276 kilns. A group of kilns and workers were taught how to implement these interventions. Another group received the same training and information on how to save money. There was no training in the control group.
Then, during the winter firing season, the researchers measured various aspects of kiln performance, including the use of fuel.
The results are promising.
Kilns that adopt these measures see great benefits. The study found that on average, fuel usage fell by about 23%. The researchers estimate that the reduction of carbon dioxide and particulate matter will be reduced by about 20% from the kiln.
“We show that simple, low-cost interventions can indeed reduce pollution,” Mahbubur Rahman said. International Research Centre for Diarrhea in Bangladesh.
These changes improve the bottom line for worker conditions and kiln owners. Brooks said they saved nearly $40,000 throughout the season due to reduced fuel use. The quality of bricks has also improved.
In fact, the kilns were impressed and a year later those who adopted the new practices were still practicing them.
But there are more kilns to sign in order to really create dents in Bangladesh’s air pollution. Research teams, including scientists from the United States, India and Bangladesh, are now working with the Bangladesh government to expand the training.
Brooks said: “It’s a story full of hope.