In South Asia, brick manufacturing stands as a vital pillar of economic development, fueling urbanization and construction across the region. Yet, despite its economic significance, the traditional brick kiln industry is a formidable source of environmental pollution and greenhouse gas emissions. Predominantly powered by coal, these kilns emit substantial amounts of carbon dioxide (CO₂), fine particulate matter (PM₂.₅), and other hazardous contaminants, posing severe risks to human health, local agriculture, and the environment. The informal nature of many of these operations, coupled with limited regulatory oversight in low- and middle-income countries, exacerbates the difficulty in addressing these emissions effectively.
A groundbreaking multidisciplinary study has emerged from researchers at Boston University School of Public Health, Stanford University, icddr,b, Greentech Knowledge Solutions, and Bangladesh University of Engineering and Technology. This study unveils an innovative, evidence-driven intervention that underscores how energy efficiency and emission reduction in brick manufacturing can be substantially enhanced through operational modifications. What sets this intervention apart is its foundation in economic incentives that align environmental benefits with the profit motives of kiln owners, circumventing the need for strict legal enforcement or heavy-handed regulation.
Published in the prestigious journal Science, the study reports the findings of a large-scale randomized controlled trial (RCT) conducted during the 2022-2023 brick kiln season in Bangladesh. The intervention encompassed a package of educational materials, hands-on training, and tailored technical assistance, provided to 276 different brick kiln owners. These resources encouraged adopting more efficient manufacturing protocols — including optimizing brick stacking to promote better heat retention and transitioning from coal to powered biomass fuels. Both measures were designed to enhance combustion completeness and minimize heat loss, key technical challenges in traditional kiln operations.
The trial’s outcomes are striking. It was observed that 65 percent of participating kiln owners readily embraced the suggested changes, leading to a significant 23% reduction in energy consumption per firing cycle. This operational shift translated directly into notable environmental improvements, with CO₂ emissions dropping by 20% and PM₂.₅ pollutants similarly declining. The intervention also yielded meaningful economic gains: coal expenditure decreased while the bricks produced were of superior quality, reinforcing the business case for sustainable practices.
From a technical standpoint, the study quantifies these emission reductions within a robust economic framework. Using a social cost of carbon valued at $185 per metric ton, the researchers calculated that the social benefits generated from decreased CO₂ emissions outweighed intervention expenses by a remarkable factor of 65 to 1. Moreover, the cost to abate one ton of CO₂ emissions through this approach was an impressively low $2.85. Follow-up assessments revealed that these modifications were not only sustained but adopted even more widely in subsequent seasons, underscoring the intervention’s practical durability and scalability.
Dr. Nina Brooks, the study’s lead author and assistant professor of global health at Boston University School of Public Health, emphasizes the significance of these results. She notes that the brick kiln sector, despite its foundational role in South Asia’s development, has remained largely stagnant regarding technological innovation. This inertia has left a substantial efficiency gap ripe for practical interventions. Brooks highlights the dual benefits realized by kiln owners who implemented these practices—both environmental and financial—proving that profit motives can dovetail effectively with health and ecological concerns when the right knowledge and incentives are delivered.
Historical attempts to regulate this sector in Bangladesh have largely faltered. Despite the industry producing approximately 27 billion bricks annually under hazardous working conditions, enforcement of environmental regulations remains minimal. For example, many brick kilns operate illegally near sensitive sites such as schools and health facilities, further exacerbating the adverse health impacts stemming from particulate pollution. Existing mandates curbing firewood usage and dictating kiln setbacks have failed to bring substantive change, highlighting the critical need for innovative, non-regulatory approaches like the one examined in this research.
Complementing the main findings, a 2024 pilot study within the intervention’s scope investigated workshops with zigzag brick kiln owners—a kiln design known for improved combustion and lower pollution but underutilized in Bangladesh. Results revealed a knowledge gap among owners regarding optimal kiln operation and skepticism over adopting changes perceived as technologically complex. Moreover, incentive structures aimed at motivating workers to uptake new practices proved less successful, illustrating the nuanced human factors at play in technological transitions in informal industries.
Debashish Biswas, a coauthor from icddr,b, underscores the essential role of labor in the success of such innovations. He stresses that technology alone does not guarantee efficacy in these settings without workplace conditions that support and empower workers. Aligning improved worker wellbeing with kiln owners’ financial interests presents an urgent avenue for future research, especially given the weak governance structures that characterize many brick-manufacturing regions in South Asia. Bridging this gap could unlock further productivity and environmental gains within the sector.
Scaling the intervention reveals immense potential for regional and global impact. If all zigzag kiln operators in Bangladesh adopt these efficiency improvements, the country could reduce its annual CO₂ emissions by approximately two percent, correlating to a massive 2.4 million metric tons reduction in a single firing season. This magnitude of impact exemplifies how local, pragmatic changes can yield outsized global benefits, offering a replicable model for other South Asian countries like India and Nepal, where brick kiln practices share similarities.
Greentech Knowledge Solutions advisor Sameer Maithel stresses the importance of indigenous innovation, pointing out that many energy-efficient practices originate from within the brickmaking community itself. Harnessing these grassroots innovations and systematizing their wider adoption can create a self-sustained pathway towards greener brick production. Developing frameworks to identify, validate, and amplify these practices stands as a pivotal future step to complement policy and technical interventions.
Co-senior author Dr. Stephen Luby of Stanford University echoes the critical importance of collaborative engagement with local stakeholders in achieving meaningful, lasting environmental progress. He notes the success of the intervention stems from trust-building and persistent interaction with kiln owners, recognizing their economic realities and operational constraints. This model of partnership offers a blueprint for sustainable development interventions not only in the brick sector but across informal industries confronting similar challenges worldwide.
In sum, this study delivers a compelling narrative: significant air pollution and greenhouse gas reductions from traditional brick manufacturing are achievable through practical, economically motivated changes that involve education and technical support, without the necessity of regulatory coercion. The findings elevate hope for the transformation of fossil fuel–dependent informal industries, emphasizing the critical intertwining of environmental health, workers’ welfare, and local economic interests. Moving forward, refining these strategies and integrating workforce-focused approaches will be vital to unlocking the full potential of cleaner, more sustainable brick production in South Asia and beyond.
Subject of Research: People
Article Title: Reducing Emissions and Air Pollution from Informal Brick Kilns: Evidence from Bangladesh
News Publication Date: 8-May-2025
Web References:
- Study DOI
- Boston University School of Public Health
- Stanford University
- icddr,b
- Greentech Knowledge Solutions
- Bangladesh University of Engineering and Technology
References:
- Brooks, N. et al. (2025). "Reducing Emissions and Air Pollution from Informal Brick Kilns: Evidence from Bangladesh." Science, DOI: 10.1126/science.adr7394.
Image Credits: Sushanta Kumar Paul
Keywords: Air pollution, Pollution control, Environmental issues, Environmental health, Carbon capture, Pollutants, Asia, Financial incentives, Government, Business, Fossil fuels, Energy
