Abstract
Bangladesh’s ~7,000 brick kilns contribute substantially to air pollution, responsible for 11% of the country’s particulate matter, 22% of black carbon, and 17% of total annual CO2 emissions . In our earlier work, we developed an intervention, Zigzag 2.0 (ZZK2.0), an intervention offering kiln owners and operators low-cost training and technical support in kiln management and insulation. In a randomized controlled trial with 276 kilns in Khulna Division (2022–2023), 65% adopted the two most important components. Adoption led to 24% less coal use per 100,000 bricks, with 21% reductions in both CO₂ and PM2.5 emissions. At the request of the Ministry of Environment, Forest and Climate Change, icddr,b scaled the intervention across 1000 kilns in 2023-25.
Yet, brick kiln workers represent a particularly vulnerable population (Boyd et al. 2025; Das et al. 2017). Our past study also delivered information to owners on the importance of incetivizing workers to adopt the technical practices, but we found owners did not take up these suggestions. Our recent study also showed about 70% workers reported lack of personal protective equipment (PPE) (Miller 2025), exposing them to risk of burns, head injuries, eye irritation, and smoke inhalation (Shaikh et al. 2012; Sanjel et al. 2016; Das et al.2017). Most lack formal contracts and endure 12–16 hour shifts near 800°C chambers (Maithel et al. 2017), often without shaded rest areas or safe water. Many are seasonal migrants trapped in debt-bondage arrangements, often bringing their entire families, resulting in a high child labor prevalence, estimated in 70% of kilns (Miller 2025). These harsh work conditions cause highly elevated risks of dehydration, heat exhaustion, long-term health complications, and even death (Flouris et al. 2024). At the same time, heat-related illness may lead to productivity losses for owners (Boyd et al. 2025). Other trafficking indicators reported less commonly by workers include wages or benefit witholding (11.8%).
Objectives:
1. Measure uptake of different workplace improvement components and improvements in workplace infrastructure and practices (PPE availability, shaded rest areas, safe drinking water access, breaks during heat periods)
2. Evaluate impact on worker-reported occupational injuries, health outcomes, wage withholding and labor trafficking indicators, and well-being.
3. Assess changes in physiological heat strain indicators (core body temperature, heart rate variability, hydration status).
We will conduct a randomized controlled trial in 200 kilns (120 intervention and 20 control) with brick kilns as the unit of randomization. The study will be implemented across Jashore, Jhenaidah and Satkhira in kilns where icddr,b has established working relationships through previous interventions. Eligible kilns are those that adopted the ZZK2.0 technical intervention in past projects with icddr,b. Intervention kilns will get an integrated training on worker conditions and improvements, as well as a refresher on the ZZK2.0 technical methods. Implementation teams will support kiln owners with planning and implementing the improvements in their kilns through the brick season. Control groups will only be surveyed at baseline and endline.