Distribution of heavy metals in surface water of Ranipet industrial area in Tamil Nadu, India.

Ranipet industrial area is about 120 km from Chennai on Chennai-Bangalore highway and is a chronic polluted area identified by Central Pollution Control Board of India. It is one of the biggest exporting centers of tanned leather in India. The total number of industries located in and around Ranipet town are 240 tanneries along with ceramic, refractory, boiler auxiliaries plant, and chromium chemicals. Studies were carried out to find out the contamination of surface water bodies due to industrial effluents. The results reveal that the surface water in the area is highly contaminated showing very high concentrations of some of the heavy/toxic metals like Cadmium ranging from 0.2 to 401.4 microg/l (average of 51.1 microg/l), Chromium 2.4-1,308.6 (average of 247.2 microg/l), Copper 2.1-535.5 microg/l (average of 95.5 microg/l), Nickel 1.6-147.0 microg/l (average of 36.7 microg/l), Lead 6.4-2,034.4 microg/l (average of 467.8 microg/l) and Zinc 20.8-12,718.0 microg/l (average of 3,760.4 microg/l). The concentration levels of these metals are much above the permissible limits in surface water and are health hazards especially for the people working in the tannery industries. It was observed that the people in the area are seriously affected and suffering from occupational diseases such as asthma, chromium ulcers and skin diseases. Distribution of metals, their contents at different locations, and their effects on human health are discussed in this paper.