Smoke comes out from kilns at a brickfield on the outskirt of Dhaka, Bangladesh on February 6, 2021.
Ahmed Salahuddin/NurPhoto by way of Getty Photographs/NurPhoto
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Ahmed Salahuddin/NurPhoto by way of Getty Photographs/NurPhoto
Throughout the dry winter months in Bangladesh, 1000’s of employees shovel thousands and thousands of tons of coal into kilns throughout the nation. As columns of hand-packed bricks bake and harden, darkish plumes of smoke pour out of greater than 8,000 smokestacks that mark the skyline of each rural and concrete areas.
“It is a number of black smoke, impacting the employees and close by villagers, but additionally the general air high quality of the area,” stated Sameer maithelan engineer with Greentech Data Options, a consulting agency in Delhi, India.
Bangladesh’s air persistently ranks among the many most polluted on Earth. Brick kilns contribute anyplace from 10 to 40% of the tiny particles that make up that air pollution. These particles can enter our lungs and even our bloodstream, inflicting well being issues, together with respiratory ailments, stroke and even cognitive issues.
However one thing so simple as stacking the bricks a distinct manner may put a vital dent in that air pollutionin accordance with a brand new research of over 275 kilns printed in Science by Maithel and his colleagues.
“That is great proof of how easy low value interventions can have a big effect on vitality use,” stated William Checkley, an epidemiologist at Johns Hopkins College who wasn’t concerned within the research. “If we are able to implement these, we may have a big affect in vitality use and emissions, bettering air high quality all through southeast Asia.”
The need of brick
Bricks are the principle constructing block for Bangladesh. The densely populated and quickly urbanizing nation produces practically 30 million bricks a yr – greater than 90% from loosely regulated, coal-burning kilns.
“It is fairly easy and cheap to arrange traditional-style brick kilns, in order that they’ve simply proliferated,” stated Nina Brooksa worldwide well being researcher at Boston College.
The method goes one thing like this: First, dun-colored clay bricks are molded with a wood field and stacked within the solar to dry. Subsequent, tons of of 1000’s of bricks are stacked within the firing chamber and coated with ash. Then, employees shovel heaps and plenty of coal because the bricks hearth, firming them up.
“The combustion effectivity of those brick kilns is basically low,” stated Brooks, that means they find yourself burning much more coal than they should, “Which is why they’re so closely polluting right here.”
Every kiln can make use of as much as 200 employees. They’re essentially the most instantly impacted by the smoke, with one research discovering practically 80% report some sort of respiratory issues. However they are not the one ones. Kilns are sometimes near densely populated areas, including to the smog that comes from metropolis life.
Brick employees stability stacks of bricks on their heads because the carry them from the kiln close to Dhaka, Bangladesh.
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Zakir Hossain Chowdhury/Anadolu Company/Getty Photographs/Anadolu
Whereas there are rules on the place kilns can and might’t function, they are not at all times adopted, stated Brooks. “We discovered that 77% of brick kilns are illegally situated too shut to a faculty.”
Trendy, high-tech kilns produce considerably much less air pollution, however they’re as much as 25 occasions costlier to construct and function. “They’ve not likely taken off,” stated Brooks.
As an alternative, the crew appeared for options that might be simpler and cheaper for the common brick producer to undertake.
Easy interventions
In his a long time of working with brick kiln house owners in India as a consulting engineer, Maithel has observed questionable practices.
Many kiln operators pack too many bricks within the kiln too tightly, he stated. That tight spacing chokes out oxygen move, which is required for environment friendly burning. It additionally means sizzling coals get caught on the high of the stack as a substitute of falling to the underside, main some bricks to be overbaked and others not fired sufficient.
He is additionally observed that employees usually shovel coal in bouts, working arduous in groups of two or three, after which all taking breaks collectively. That leads to uneven fueling, which may stymie effectivity too.
As an vitality methods engineer, Maithel knew that just a few easy adjustments may actually assist. Merely stacking the bricks in a zig-zag sample that will increase airflow and guaranteeing coal will get delivered extra persistently ought to assist the kilns function extra effectively, he stated.”The higher you’ll be able to present gas and air mixing, the chance of black smoke might be much less.”
To see if such easy interventions may assist cut back air air pollution and increase income, the crew deliberate a large experiment throughout 276 kilns. One group of kiln house owners and employees have been taught methods to implement these interventions. One other group received the identical coaching plus data on how the adjustments would lower your expenses. The management group received no coaching.
Then, throughout firing season within the winter, the researchers measured numerous elements of kiln efficiency, together with gas use.
So, did it work?
The outcomes have been promising.
Kilns that adopted these measures noticed vital advantages. On common, gas use dropped by about 23 %, the research discovered. The researchers estimate that would cut back the carbon dioxide and particulate matter popping out of the kilns by about 20%.
“We confirmed that easy, low-cost interventions can actually cut back air pollution,” stated Mahbubur Rahman, an environmental well being researcher on the Worldwide Centre for Diarrhoeal Illness Analysis, Bangladesh.
And the adjustments improved each employee circumstances and the underside traces for kiln house owners. Over the season, they’d saved near $40,000 every due to decreased gas use, stated Brooks. Brick high quality went up as effectively.
Actually, kiln house owners have been so impressed {that a} yr later, those who had adopted the brand new practices have been nonetheless practising them.
However to actually make a dent in Bangladesh’s air air pollution, many extra kilns have to signal on. The analysis crew, which incorporates scientists from the U.S., India and Bangladesh, at the moment are working with the Bangladeshi authorities to increase this coaching.
“It is a hopeful story,” Brooks says, “of a spot the place options are fairly possible.”
