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 Photos/NurPhoto
conceal caption
toggle caption
Ahmed Salahuddin/NurPhoto by way of Getty Photos/NurPhoto
In the course of the dry winter months in Bangladesh, hundreds 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 plenty of black smoke, impacting the employees and close by villagers, but additionally the general air high quality of the area,” mentioned Sameer maithelan engineer with Greentech Information 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 illnesses, stroke and even cognitive issues.
However one thing so simple as stacking the bricks a special method may put a important dent in that air pollutionin response to a brand new research of over 275 kilns revealed in Science by Maithel and his colleagues.
“That is great proof of how easy low price interventions can have a big effect on power 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 major affect in power use and emissions, bettering air high quality all through southeast Asia.”
The need of brick
Bricks are the primary constructing block for Bangladesh. The densely populated and quickly urbanizing nation produces practically 30 million bricks a 12 months – greater than 90% from loosely regulated, coal-burning kilns.
“It is fairly easy and cheap to arrange traditional-style brick kilns, so that they’ve simply proliferated,” mentioned 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, a whole lot of hundreds of bricks are stacked within the firing chamber and coated with ash. Then, employees shovel tons and plenty of coal because the bricks hearth, 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 sort 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 Photos/Anadolu
conceal caption
toggle caption
Zakir Hossain Chowdhury/Anadolu Company/Getty Photos/Anadolu
Whereas there are laws 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 college.”
Fashionable, high-tech kilns produce considerably much less air pollution, however they’re as much as 25 occasions dearer to construct and function. “They’ve probably not taken off,” mentioned Brooks.
As an alternative, the workforce seemed for options that will 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 mentioned. That tight spacing chokes out oxygen circulation, which is required for environment friendly burning. It additionally means scorching coals get caught on the prime 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 onerous in groups of two or three, after which all taking breaks collectively. That ends in uneven fueling, which might stymie effectivity too.
As an power techniques engineer, Maithel knew that just a few easy modifications may actually assist. Merely stacking the bricks in a zig-zag sample that will increase airflow and making certain coal will get delivered extra persistently ought to assist the kilns function extra effectively, he mentioned.”The higher you’ll be able to present gasoline and air mixing, the likelihood of black smoke will probably be much less.”
To see if such easy interventions may assist cut back air air pollution and increase income, the workforce deliberate an enormous experiment throughout 276 kilns. One group of kiln house owners and employees had been taught methods to implement these interventions. One other group received the identical coaching plus data on how the modifications would lower your expenses. The management group received no coaching.
Then, throughout firing season within the winter, the researchers measured varied facets of kiln efficiency, together with gasoline use.
So, did it work?
The outcomes had been promising.
Kilns that adopted these measures noticed important advantages. On common, gasoline use dropped by about 23 %, 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 easy, low-cost interventions can actually cut back air pollution,” mentioned Mahbubur Rahman, an environmental well being researcher on the Worldwide Centre for Diarrhoeal Illness Analysis, Bangladesh.
And the modifications improved each employee circumstances and the underside strains for kiln house owners. Over the season, that they had saved near $40,000 every due to decreased gasoline use, mentioned Brooks. Brick high quality went up as properly.
In actual fact, kiln house owners had been so impressed {that a} 12 months later, people 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 workforce, 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.”
