Analysis of environmental pollution in Sundarbans

摘要

The Sundarbans is the largest, biologically richest, and most extensive mangrove forest in the world, which is also a world heritage site. Heritiera fomes (Sundri) tree is the most important ecologically dominant and economically valuable tree species and there are 3.5 million in Sundarbans. However, heavy metal contamination is affecting millions of the trees & people in Sundarbans (Awal, 2007). 45.2 million of Sundri trees have been affected in Sundarbans (Chaffey et, al., 1985). Heavy metals are natural constituents of the earth's crust, and accumulation of heavy metals in soil is responsible for pharmacological activity in plants. Prolonged exposure to heavy metals such as Al, As, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, In, K, Mg, Mo, Mn, Na, Ni, P, Pb, Rb, Sb, Sc, Se, Si, Sn, Sr, Ti, V, Y, Zn, can cause deleterious health effects in humans & plants. Excessive levels can be damaging to the organism. Heavy metals disrupt metabolic functions and they accumulate and thereby disrupt function in vital organs and glands such as the heart, brain, kidneys, bone, liver, etc. They displace the vital nutritional minerals from their original place, thereby, hindering their biological function. There are many ways by which these toxins can be introduced into the body such as consumption of foods, skin exposure, and the inhaled air. Plants experience oxidative stress upon exposure to heavy metals that leads to cellular damage and disturbance of cellular ionic homeostasis. So, the loss of H. fomes & loss of surrounding people will have a major impact on the Sundarbans mangrove ecosystem, as well as lead to economic losses. Despite various hypotheses as to the causes of this top-dying, the underlying causes are still not well understood. The present work has explored some of the possible factors involved, focussing particularly on the relationship between the amount of top-dying in different places and the concentrations of a number of chemical elements present in the soil and water and human bodies, in order to test the hypothesis that chemical pollution might be responsible.