The study was conducted to estimate total mercury in water and sediment of Bidyadhari river of Indian Sundarban delta in pre-monsoon, monsoon and post-monsoon period. Bidyadhari river presently serves as a sewage and excess rainwater outlet from the Kolkata metropolitan and adjacent area which ultimately empties at the Bay of Bengal in the course of the Indian Sundarban delta.

Background concentrations of heavy metal ions concentration in soils are important due to their pollution potential and toxic effect of these elements on human health and the environment. These metals in soils in the vicinity of paper manufacturing industry were studied. Concentrations of these heavy metal ions (e.g., Pb, Zn, Cd,Cr) were analyzed using Atomic Absorption Spectrophotometer (A.A.S). The findings revealed that the average concentrations of these metals in soil samples were three to ten times higher than the permissible limits.

Cypermethrin is a synthetic pyrethoid mainly used against mango insect pests. Clams are good indicators of pesticide pollution and are known to be tolerant to pesticide accumulation. Acute toxicity experiment of Cypermethrin is carried out on estuarine clam, Marcia opima. The clam exhibited significant increase in protein content of gill in LC0 and LC50 group of clams while foot, male gonad and female gonad exhibited considerable decrease in protein content. Whereas, in LC0, mantle showed high protein content. In LC50 group, hepatopancreas exhibited high protein content.