Toxicity Assessment for Aquatic Ecosystem, Soil and Crops in Tongi, Bangladesh

As Tongi is an industrial area, massive amounts of effluents generated by the industries end up in the river and soil of this region. These wastes contain an excessive amount of heavy metals, which is detrimental for both environment and living organisms. The concentration of metals, Cadmium (Cd), Chromium (Cr), and Lead (Pb) were studied for water, soil and vegetable samples in order to understand the current pollution scenario of Tongi industrial area, Bangladesh. In this research, studies were conducted on water and soil by using water quality parameters, geo-chemical index, contamination factor, and pollution load index. This research also investigated the daily metal intake by people consuming the vegetables grown from that contaminated soil. Experimental observations reveal that the water of those areas is polluted with the concentration of Cd (0.0542-0.1728) mgL-1, Pb (0.0421-0.245) mgL-1 and Cr (1.0622-2.4357) mgL-1. However, the study also demonstrated that the soil of these areas is severely contaminated with Cd(4.42-100.564)mgkg-1, but moderately contaminated with Pb and Cr, and the rate of heavy metal intake is within the World Health Organization (WHO) standard among the consumers of vegetables grown in the local agricultural land. Cadmium concentration is observed to be higher in water and soil compared to the concentrations of lead and chromium, which might be due to the high cadmium containing industrial effluent discharge in the river. This study demonstrates the requirements for wastewater containing heavy metal discharge regulations into the river water, and it is also concluded that the assessment area is extremely contaminated with cadmium concentrations.