Environmental pollution - Bank Town, Savar, Dhaka - part I

This photo is of the small canal flowing through the north boundary of bank town. This canal water contains industrial run-offs; and changes colour from time to time, depending on which dye is used in the dyeing factories. People are sometimes seen to fish here, providing evidence of bioaccumulation in the fishes. Upon close inspection, one can also see the massive waste-dumps at both banks of the canal. All sorts of wastes are dumped here, many containing hazardous material. Although these become food havens for crows, kites, herons and pigs, they are unaware of ongoing bioaccumulation of hazards in them. These fishes and pigs are ultimately consumed by humans, adding another layer in biomagnification.

This shows our river Bangshi (although Google calls her "Karnatali"). The water contains run-off from multiple dyeing factories; one of which is shown in the following photos.

This water is ink-black and smells like ink too. It mostly contains organic dyes, heavy metals and catalysts. This makes the river water black most of the time, and a strong stink comes out if agitated.

Although fishes are not found here, the river-bank is used for agricultural purposes, shown in the next picture.

Many vegetables are grown here. Sometimes local dairy farmers feed their cows the grass growing on the river bank, causing biomagnification (the phenomenon of increasing concentration of pollutants in higher tropic level organisms of the food chains). The final consumer, humans have to take the final toll of biomagnification as they consume the vegetables and dairy products.

The next photo is unfortunately very common. Here the ash-colored substance is the sludge taken out of the drain. It contains household wastes and decomposed material. It is an open source of pathogenic bacteria and protists. Furthermore, percolating pollutants from these sludges accumulate in the grasses and plants in the vicinity, and sometimes are later consumed by cows and goats, leading to bioaccumulation.