Impact of brick kiln emissions on soil quality: A case study of Ashulia brick kiln cluster, Bangladesh

Abstract

There are more than 7000 active brick kilns in Bangladesh to meet the country's growing demand for building materials. The country's brick kiln industry employs more than 1.0 million people and contributes around 1.0% to the national economy. A substantial number of the country's brick kilns are located in the Greater Dhaka Region. Urban air pollution has become a great concern in this region due to the stack emissions during the brick manufacturing period. Estimation revealed that around 1.80 million tons of carbon dioxide, 302,200 tons of carbon monoxide, 23,300 tons of particulate matters, 15,500 tons of sulfur dioxide, and 6000 tons of black carbon are emitted to manufacture 3.50 billion bricks annually. In previous research contributions, the effect of air pollution from the brick kiln operation in this region has been addressed. However, no past study has assessed the effect of heavy metals released from brick kiln emissions during their production period on the adjacent soil environment of this region. Therefore, the current study aimed to determine heavy metal concentrations in the top soils and their adverse effects on the soil quality from active brick kilns, situated in the Ashulia region of Greater Dhaka. The soil sampling within the vicinity of the studied three brick kilns was performed at different radial distances ranging from 0 to 400 m during the brick production period. The concentration level of the analyzed heavy metal contents from the 15 sampling locations was found in the following order, iron > magnesium > calcium > manganese > zinc > nickel > chromium > copper > arsenic > lead > cadmium. The concentration level of cadmium (mean 2.82 mg.kg−1) resulted to be very high than its threshold limit (1.40 mg.kg−1) in the majority of the sampling locations. A significantly high level of soil pollution was evaluated within the study area through the applied pollution evaluation indices. The study findings indicate prospective damage to the studied soil environment and ecological settings of Ashulia, due to the emissions from the brick kilns which require suggested emission control and soil remediation actions, and implementation of eco-brick manufacturing technologies without further delay.