Abstract

Brick manufacturing is the fastest-growing industrial sector in many countries (like china, India, Bangladesh and Pakistan) and among the top three sectors, along with vehicle exhaust and resuspended road dust, contributing to the air pollution and health problems in Dhaka (Bangladesh). The total emissions from the brick manufacturing in the Greater Dhaka region, to produce 3.5 billion bricks per year has been estimated about 23,300 tons of particulate matter having aerodynamic diameter < 2.5 μm (PM_2.5), 15,500 tons of sulfur dioxide (SO₂), 302,000 tons of carbon monoxide (CO), 6,000 tons of black carbon (BC) and 1.8 million tons of carbon dioxide (CO₂)_. Emission of individual air pollutant from brick kilns varied significantly during a firing batch (seven days) and between kilns. Average emission factors per 1,000 bricks were 6.35 to 12.3 kg of CO, 0.52 to 5.9 kg of SO₂ and 0.64 to 1.4 kg of particulate matter (PM). Presently sulphur dioxide (SO₂), oxides of nitrogen (NO_x) and suspended particulate matter (SPM) are the main issue pertaining to air pollution problems in developing countries, where it contributes both to urban pollution and to regional acid depositions. Among man-made sources, coal combustion in stationary sources accounts for 74%, industries 22% and transportation 2% of the total oxides of sulphur (SO_x)_. and it is considered that SO₂ is the chief emission in brick production. On an international basis, 75 to 85% of SO₂ emissions are the result of fossil fuel burning. It is predictable that just about 93% of the global SO₂ emissions are emitted in the northern hemisphere. It has been revealed that biomass is responsible for the emission of both trace and non trace gases such as carbon dioxide (CO₂), methane (CH₄) and oxides of nitrogen (NO_x) from traditional brick industries and lots of toxic fumes containing suspended particulate matters rich in carbon particles and high concentration of CO and SO_x get produced. Studies have shown the average value of particulate matter of size less than ten microns and total suspend particles for the pre-operation time of brick kilns was 0.029 and 0.033 mg/m³, respectively whereas, it reached 0.050 and 0.056 mg/m³, respectively during the brick kiln operation time. Similarly, recent studies on brick kilns in District Budgam of Kashmir valley (India) have shown some major negative impacts on the environment in respect of air quality, human health and vegetation in particular.

Key words: Pollution, emissions, environment, industrialization, transportation, brick kiln, human health, vegetation.