Bangladesh must modernise brickmaking to curb emissions and land loss

Bangladesh's brick manufacturing industry plays a major role in infrastructure development and rapid urbanisation.

The sector supplies an estimated 80% of the bricks used in construction, with roughly 8,000–10,000 kilns producing about 28 billion bricks a year. Yet the industry's growth has come with a heavy environmental and public health cost, driven by high consumption of natural resources and large-scale emissions.

According to the Department of Environment (DoE) (December 2022), Bangladesh has 7,881 brick kilns. Of these, 3,248 are legal and 4,633 operate illegally—around 59% of the total. The number of illegal kilns has reportedly risen by about 1,500 over the last four years, with most of the increase occurring in the past three years.

The sector has expanded sharply over the last decade. In 2013, Bangladesh reportedly had 4,959 kilns; by 2022, the figure had risen to 7,881, an increase of about 62%.

In terms of technology, the DoE data show 1,373 fixed-chimney kilns, 6,352 zigzag kilns, 149 "auto" brick kilns (hybrid Hoffman and tunnel kilns) and six using other technologies.

Air pollution and public health risks

Brick kilns are widely considered a major source of environmental pollution in Bangladesh. Emissions affect air, soil and water quality, and contribute to biodiversity loss and climate risks.

Kilns release large quantities of fine particulate matter (PM₂.₅ and PM₁₀), which can enter the lungs and increase risks of respiratory illness. They also emit carbon monoxide (CO), sulphur dioxide (SO₂) and nitrogen oxides (NOₓ), which are linked to respiratory problems and can contribute to acid rain. The use of low-quality coal and wood produces black carbon, a strong contributor to global warming.

People living near kilns—particularly children and older people—are more exposed. Prolonged exposure to polluted air can increase the risk of asthma, bronchitis, pneumonia and chronic obstructive pulmonary disease (COPD). Sulphur compounds and fine dust may also cause eye irritation, skin problems and lung infections. Among pregnant women, air pollution is associated with higher risks of preterm birth and low birth weight.

Dhaka and its surrounding areas have a high concentration of kilns. Estimates suggest around 2,500 kilns operate around the capital, and that 25–30% of Dhaka's air pollution comes from brick kilns. A 2019 World Bank study reported that around 6.8 million tonnes of pollutants are released into the air annually from brick kilns in Dhaka alone.

Brick production depends heavily on topsoil, often collected from agricultural land. An estimated 60,000 acres of topsoil are used each year for brickmaking, reducing soil fertility and accelerating erosion—risks that can undermine long-term food security.

Emissions from kilns can degrade soil quality by reducing organic matter. Crops near kilns may show leaf yellowing or scorching, which can lower yields of grains and vegetables. Dust and chemicals released into the air can mix with rainwater and contaminate ponds, canals and groundwater. In many areas, kiln waste is reportedly dumped into nearby rivers and water bodies, threatening aquatic life and reducing access to safe water.

Many kilns continue to burn wood, adding pressure on forests. Forest clearance is also linked to expanding kiln operations in some areas, affecting the habitats of birds, insects and other wildlife. Estimates suggest about two million tonnes of wood are burned annually in brick production, contributing to deforestation and biodiversity loss.

Dust settling on leaves can reduce sunlight absorption, weakening tree growth and disrupting local ecosystems. Over time, emissions from coal and wood burning release carbon dioxide (CO₂) and black carbon, contributing to climate change. Studies cited by sector observers suggest brick kilns in Bangladesh emit around 15 million tonnes of CO₂ annually, and that temperatures in kiln-dense areas can be 2–3°C higher than surrounding areas, affecting local microclimates.

To control pollution, the government enacted the Brick Manufacturing and Brick Kiln Establishment (Control) Act, 2013 (amended 2019) and gazetted the Air Pollution (Control) Rules, 2022. Enforcement drives to shut illegal kilns have been ongoing. However, continued growth in kiln numbers—especially illegal operations—remains a major challenge.

Many developed countries rely on modern, low-emission kiln technologies and alternative construction materials to reduce environmental harm. Technologies such as tunnel kilns, hybrid Hoffman kilns (HHK) and vertical shaft brick kilns (VSBK) can recycle heat, reduce fuel use and lower emissions while improving brick quality. Tunnel kilns, for example, control temperature more efficiently across stages of firing, reducing fuel waste.

There is also a growing shift to alternatives such as autoclaved aerated concrete (AAC) blocks, concrete blocks and recycled bricks, which can reduce dependence on topsoil and lower carbon intensity compared with traditional fired bricks.

Stricter enforcement of environmental standards in many countries includes air filtration systems for smoke treatment, tighter licensing and ongoing monitoring. Some producers also invest in afforestation and carbon-balancing measures as part of compliance and sustainability commitments.

Bangladesh will need a coordinated transition to cleaner brick technologies and sustainable alternatives to reduce pollution and protect public health. Expanding cleaner kiln technologies and increasing adoption of AAC and concrete blocks could significantly cut emissions and reduce pressure on agricultural land.

A long-term strategy—combining technology upgrades, market incentives, and stronger enforcement against illegal kilns—will be critical to protecting the environment while supporting construction demand.

Professor Dr Ahmad Kamruzzaman Majumder is the dean of the Faculty of Science, professor in the Department of Environmental Science at Stamford University Bangladesh, joint secretary of Bangladesh Poribesh Andolon (BAPA), and chairman of the Center for Atmospheric Pollution Studies (CAPS).

Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect those of The Business Standard.