Smoke comes out from kilns at a brickfield on the outskirt of Dhaka, Bangladesh on February 6, 2021.
Ahmed Salahuddin/NurPhoto through Getty Photographs/NurPhoto
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Ahmed Salahuddin/NurPhoto through Getty Photographs/NurPhoto
Throughout the dry winter months in Bangladesh, 1000’s of employees shovel hundreds of 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 variety of black smoke, impacting the employees and close by villagers, but additionally the general air high quality of the area,” mentioned Sameer Maithel, an 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 wherever 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 special manner may put a important dent in that air pollution, in line with a brand new research of over 275 kilns revealed in Science by Maithel and his colleagues.
“That is fantastic proof of how easy low value interventions can have a big effect on vitality use,” mentioned 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 influence 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,” mentioned Nina Brooks, a 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, a whole bunch of 1000’s of bricks are stacked within the firing chamber and coated with ash. Then, employees shovel heaps and many coal because the bricks fireplace, firming them up.
“The combustion effectivity of those brick kilns is admittedly low,” mentioned 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 form of respiratory issues. However they don’t seem to be the one ones. Kilns are sometimes near densely populated areas, including to the smog that comes from metropolis life.
Brick employees steadiness stacks of bricks on their heads because the carry them from the kiln close to Dhaka, Bangladesh.
Zakir Hossain Chowdhury/Anadolu Company/Getty Photographs/Anadolu
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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 don’t seem to be at all times adopted, mentioned 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,” mentioned Brooks.
As an alternative, the staff appeared for options that might be simpler and cheaper for the typical brick producer to undertake.
Easy interventions
In his many years of working with brick kiln house owners in India as a consulting engineer, Maithel has seen questionable practices.
Many kiln operators pack too many bricks within the kiln too tightly, he mentioned. 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 seen that employees typically shovel coal in bouts, working exhausting in groups of two or three, after which all taking breaks collectively. That ends in uneven fueling, which might stymie effectivity too.
As an vitality programs 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 mentioned.”The higher you’ll be able to present gas and air mixing, the likelihood of black smoke shall be much less.”
To see if such easy interventions may assist scale back air air pollution and enhance earnings, the staff deliberate a large experiment throughout 276 kilns. One group of kiln house owners and employees had been taught easy methods to implement these interventions. One other group received the identical coaching plus information on how the adjustments would get monetary savings. The management group received no coaching.
Then, throughout firing season within the winter, the researchers measured varied points of kiln efficiency, together with gas use.
So, did it work?
The outcomes had been promising.
Kilns that adopted these measures noticed important advantages. On common, gas use dropped by about 23 p.c, the research discovered. The researchers estimate that would scale back the carbon dioxide and particulate matter popping out of the kilns by about 20%.
“We confirmed that straightforward, low-cost interventions can actually scale back air pollution,” mentioned Mahbubur Rahman, an environmental well being researcher on the Worldwide Centre for Diarrhoeal Illness Analysis, Bangladesh.
And the adjustments improved each employee situations and the underside traces for kiln house owners. Over the season, that they had saved near $40,000 every due to diminished gas use, mentioned Brooks. Brick high quality went up as effectively.
In actual fact, kiln house owners had been so impressed {that a} yr later, those who had adopted the brand new practices had 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 staff, which incorporates scientists from the U.S., India and Bangladesh, are actually 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.”
