Esteak Ahammed Emon
Bangladesh is the 2nd largest brick producer in South Asia, followed by India. According to the world bank, there have more than 7000 brick kilns operating in Bangladesh, producing an estimated 27 billion bricks annually that contribute 1% to the national GDP and employ nearly 1 million people. Rapid urbanization, industrialization and construction of buildings in Bangladesh use bricks from several past decades. Due to the unavailability of stone aggregate, brick is the main building material for the country’s construction industry.
This has reinforced brick manufacturing industry a fastest growing sector in Bangladesh due to increasing demands and availability of raw materials such as mud soil or clay, fuel materials and cheap labour.
There are generally six types of brick kilns in Bangladesh: (i) bull’s trench kilns (BTKs), (ii) fixed chimney kilns (FCKs), (iii) improved zigzag kilns, (iv) vertical shaft brick kiln (VSBKs), (v) Hoffman kilns, and (vi) tunnel kilns. Prior to 2004, most of the kilns in Bangladesh were BTKs, a relatively primitive design developed over 150 years ago. BTKs are highly polluting and energy inefficient. After the promulgation of the brick burning rules in 2002, most BTKs were converted to FCKs, which are more energy efficient while fine particulate emissions remain the same. The brick sector satisfactorily complied with the government’s directive in 2002 to construct chimneys at the designated 120–130 feet (36.6–39.6 meters) height.
Brick kilns in Bangladesh are mostly informal and small-scale operations. More than 90 percent of brick kiln owners are small-scale operators. Most FCKs are individually owned, with each owner possessing one kiln only. Multiple ownership of one kiln and multiple kilns under the same ownership are rare. In a few cases, established business houses own brick kilns that are part of a portfolio of industrial establishments. The kiln owners are organized as the Bangladesh Brick Manufacturers Owners Association (BBMOA). This association is expected to support actions perceived as beneficial to the interest of its members; thus, it must be involved in any reform concerning the brick sector.
Brick kilns have a negative effect on agricultural productivity. Agricultural soil is the major raw material for brickmaking industry in Bangladesh. They use the upper layer of the soil, which is known as top soil. Depletion of topsoil with high organic content for brick-making is a major concern for agricultural production. Top soil is the most important part of soil for agricultural purpose. Topsoil is the upper, outermost layer of soil, usually the top 5–10 inches (13–25 cm). It has the highest concentration of organic matter and microorganisms and is where most of the Earth’s biological soil activity occurs. Topsoil is composed of mineral particles, organic matter, water, and air.
Brick kilns, involving the burning of low-grade coal, are one of the major sectors that contribute to air pollution in South Asia. The brick sector is responsible for up to 91% of total Particulate Matter (PM) emissions in some South Asian cities. In Bangladesh, the contribution of the brick sector to the total annual CO2 emissions of the country (17%) is far more significant than its GDP contribution (1%). Brick kilns are also estimated to emit 22 and 37 kt/year of PM2.5 and PM10 respectively. The airborne particulates and associated trace metals have been associated with both acute and chronic adverse health effects, mainly respiratory disease, lung cancer, heart disease, and damage to other organs. Various gaseous and particulate pollutants from brick kilns show negative impacts on the adjacent vegetation and have direct and indirect effects on agriculture.
Brick kilns are major sources of greenhouse gas in Bangladesh, emitting annually 6 to 9 million tons of CO2. Such high levels of emissions are a result of the use of age-old technologies and substandard fuels such as high Sulphur coal, tires and wood used in the kilns. The brick kiln laborer’s, after brick burning, open the air pockets of the burner to cool it down, which emits hot air and ashes that spread over to the nearby paddy fields, during brick production.
According to the Food and Agriculture Organization, the amount of total agricultural land in Bangladesh is decreasing day by day for large population. Now a days, for those outdated brick kilns have becomes another awful anxiety for it. Brick kilns are polluting both air and soil, which is an appalling matter for the cultivation. Besides the Brick kilns the productivity of soil being damaged, biodiversity is being harmed, this leads to harmful impacts on health. For uses top soil land area becomes low, there can be appear water logging. Now at the time the use of environment friendly brick kilns can be the best solution of this acrid problem. As of late, government should take apt initiative about brick kilns for welfare of the environment as well as the country.
More than 90 percent of the country’s brick kilns use 150 years old energy intensive and highly polluting technology. The new Hybrid Hoffman technology has the potential to save energy and resources and help build a cleaner Bangladesh. The Hybrid Hoffman Kiln’s success is its ability to completely burn most of the fuel that is mixed into the bricks during firing, and thereby drastically reduce energy use and production costs. It also dries the bricks by directing hot air into the tunnel from the annular kiln, which blocks greenhouse gas emission. So, government should setup this bricks technique to arrive on prosperous Bangladesh.
Author is a Student of Environmental Science and Engineering Department at Jatiya Kabi Kazi Nazrul Islam University, Trishal, Mymensingh—2224, Bangladesh
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