ANJUM FAROOQUI
Abstract
The surface soil and sedimentary soil profile of 1.5 m deep from the ground surface deposited during Holocene in the Adyar estuary is heavily loaded daily by the Chennai metropolitan waste water. An average of 500 ..ig/g toxic arsenic concentration was found in surface soil samples near the Elphinstone bridge, Adyar (Chennai, south-east). The concentration is high throughout the 1.5 m deep sedimentary soil in the area showing concentrations ranging from 60-1200 tg/g. Analysis of Arsenic accumulation in leaves of some plants growing in the estuary indicates it uptake through soil. Thespesia populnea and Acacia are good accumulators of Arsenic followed by Prosopis juliflora and La n t ana carnara. The latter two species are abundant exotic plant spices in the estuary perhaps tolerant to the pollution load. On the other hand. These pesia populnea, a mangrove associate is rare in the estuary that probably indicates its susceptibility to increasing authropogenic pressure. Most of the Arsenic analysed in soil is water soluble and high in the stagnant sewage dump area along the banks of the Ayar river than the midstream. It is likely that the contamination is through number of arterial drainage joining the river. The possible source of Arsenic may be groundwater or industrial effluent. Arsenic may find its way into the dietary intake of human beings and cattle through the products from aquaculture, pisciculture and agriculture dependant on the water from Adyar estuary.