Mercury Problems

In the world today the total load of mercury emissions is about 6 to 7.5 thousand tonnes per year. The emission due to human civilisation got a spurt since the days of gold and silver rush since the sixteenth century. The effluents carrying mercury ultimately unloads it in lakes and seas. Fish containing the biomethylated mercury poses as the major source of mercury contamination in man, who is under increasing toxicological pressure from other adverse eco-components as well. The factors controlling mercury contamination in aquatic environment and the load generated in the fish-eating population have been shown with response to dose- response relationship and the WHO prescribed limits. In this paper an analysis has been attempted to focus on the major causative factors of mercury contamination through human activities. An evaluation of the recent activities such as construction of dams for hydroelectric power generation, impoundment for other water reservoirs, cutting new lakes, deforestation and erosion of forest soil enriched in toxic metals has been attempted with notes on the flood perturbation of the eco- stability. An overview has been made of the salient aspects accelerating the processes of methylation in the present day ecosystem.