Brick Production Tweaks Can Significantly Reduce Air Pollution in Bangladesh Says New Study

    The process of brickmaking in Bangladesh involves stacking bricks and burning pulverized coal in between stacks of bricks. A new study shows that how those bricks are stacked and how the coal is placed can result in significant air pollution emissions reduction. Brick kiln pollution in South Asia is a major source of pollution, and efforts to regulate the industry have largely failed in the past in Bangladesh. According to the Stanford Report, the trials convinced regulators in Bangladesh that the new tweaks will work.

“The randomized controlled trial tested an intervention involving simple, low-cost operational changes, such as continuous fuel feeding and more efficient brick stacking. The approach reduced coal use by 23% and carbon dioxide emissions by about 20%, while improving brick quality and reducing owner costs. The intervention's success led initially skeptical Bangladesh government officials to encourage rolling out the intervention nationwide.”

     Brick making in Bangladesh is considered to be an informal industry in a low-income developing country. Regulation of informal industries in low-income countries has a long record of failure. However, the improvements in cost reduction and pollution reduction in this case suggest that the practices should become widely adopted. It was also noted that exploitative labor practices, such as child labor, are sometimes used in informal industries, including brick making, and that those who make brick by this method also face significant pollution exposure. Brick making in Bangladesh, where 27 billion bricks are produced annually, and in South Asia as a whole, is a big industry. However, in Bangladesh, it accounts for 17% of CO₂ emissions and 11% of PM2.5 emissions annually.

     Researchers at the Boston School of Public Health, Stanford University, icddr,b, Greentech Knowledge Solutions, and the Bangladesh University of Engineering and Technology developed the new methods. Results of the randomized controlled trials:

“…showed that brick kiln owners in Bangladesh are willing and able to implement cleaner and more efficient business practices within their operations—without legal enforcement—if they receive the proper training and support, and if those changes are aligned with their profit motives.”

     The study showed that energy-efficient changes to the production process, such as streamlining brick stacking and using powered biomass fuel, lead to more complete fuel combustion and a reduction of heat loss in the kilns. This is a success story as the following statement from Boston University School of Public Health shows’

“The study found that 65 percent of the brick kiln owners adopted these changes, which led to a  23-percent reduction in energy use. The changes substantially improved air quality, contributing to 20-percent reductions in CO₂ and PM2.5 emissions. This intervention also brought substantial savings in coal expenditures and higher-quality bricks. Notably, the researchers estimated that the social benefits due CO2 reductions from the intervention outweighed costs by a factor of 65 to 1 and that the CO2 reductions were achieved at the low cost of $2.85/ton. When the team returned to participating brick kilns the next year, they found adoption of the improved practices had not only sustained but increased.”

“Our findings demonstrate that brick kiln owners are willing to embrace simple changes that protect human and environmental health when they have the knowledge and training, and those changes deliver tangible economic gain.”

     Current regulations ban the use of firewood for brick making and have distance requirements from schools and health facilities. However, enforcement of these rules is often lacking.

“An important area for future research is identifying strategies to improve work conditions that are aligned with kiln owners’ profit motives and may be implemented within a weak regulatory state.”

“The researchers’ energy-efficient intervention may be scalable across South Asia, such as in India and Nepal, where brick manufacturing practices are similar—and possibly across other industries. Future research will consider how to best scale the intervention, as well as develop the next generation of efficiency improvements for the brick industry.”

     A 2024 pilot study in Energy Research & Social Science noted:

“Traditional kilns—in particular fixed chimney kilns—are highly inefficient. A zigzag kiln, which represents a modest change over the fixed-chimney kiln and is more energy efficient, is still traditional and informal. An existing fixed-chimney kiln can be retrofitted into zigzag kiln by making some modifications to the kiln structure, using a fan, and changing how bricks are stacked inside the kiln. When constructed and operated properly, a zigzag kiln enables more complete combustion of fuel and more uniform heat distribution in the kiln, which reduces emissions but also increases the profitability of a kiln through reduced fuel costs and increased production of high-quality bricks. Because zigzag kilns are theoretically more energy efficient and less polluting, they are classified as “environmentally friendly” by the GoB. But when zigzag kilns are constructed or operated incorrectly, as the majority in Bangladesh are, they may be just as polluting as fixed-chimney kilns. Consequently, the traditional brick industry remains a major source of greenhouse gas emissions and air pollution.”

     The Editor’s summary, abstract, and conclusions from the new paper in Science are shown below. This is a public health success story that has the potential to be repeated as technological advancements to increase efficiency and reduce emissions are introduced to informal industries around the world.

 

 

     

 

References:

 

Research guides Bangladesh toward cleaner brick production. Stanford Report. Stanford University. May 8. 2025.  Research guides Bangladesh toward cleaner brick production | Stanford Report

Researchers Develop Practical Solution to Reduce Emissions and Improve Air Quality from Brick Manufacturing in Bangladesh. Bangladesh University and Stanford School of Public Health. May 8, 2025. Researchers Develop Practical Solution to Reduce Emissions and Improve Air Quality from Brick Manufacturing in Bangladesh | SPH

Reducing emissions and air pollution from informal brick kilns: Evidence from Bangladesh. Nina Brooks, Debashish Biswas, Sameer Maithel, Grant Miller, Aprajit Mahajan, M. Rofi Uddin, Shoeb Ahmed, Moogdho Mahzab, Mahbubur Rahman, and Stephen P. Luby. Science. 8 May 2025. Vol 388, Issue 6747. Reducing emissions and air pollution from informal brick kilns: Evidence from Bangladesh | Science

Building blocks of change: The energy, health, and climate co-benefits of more efficient brickmaking in Bangladesh. Nina Brooks, Debashish Biswas, Sameer Maithel, Sonal Kumar, Mohammad Rofi Uddin, Shoeb Ahmed, Moogdho Mahzab, Grant Miller, Mahbubur Rahman, and Stephen P. Luby. Energy Research & Social Science. Volume 117, November 2024, 103738. Building blocks of change: The energy, health, and climate co-benefits of more efficient brickmaking in Bangladesh - ScienceDirect