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The leather industry is one of the major foreign exchange earners in India. The tanning process uses many chemicals in the procedure. Chromium is one of them. The hexavalent form of chromium that is used in tanning causes cancer, stomach-ache, headache, dizziness, diarrhoea, and allergies to those exposed to it.

Chromium tanning is a large source of pollution in India. The chromium is spread from the industry areas by being used as irrigation water by farmers on their land where it leaks to the groundwater. Leakage from the industry and the drains with waste water leading to a nearby river or lake is another way of spreading. Solid waste from the tanneries can be seen in the areas surrounding the tanneries as piles of skin pieces with the characteristic blue colour that comes from the chromium treatment. During the rain periods rainwater washes out the chromium from the skin pieces and percolates through the soil.

There are several ongoing research programs on the effects of chromium exposure, on alternative chemicals to use in tanning and on crops that can absorb the dangerous form of chromium. Tamil Nadu Agricultural University works together with the Pollution Control Board of Tamil Nadu and the industry owners in Erode district with the purpose to find a solution to the problems that the tanneries in Erode district causes. Alternative crops that can absorb chromium is experimented with. The project also does regular surveys of the levels of chromium in wells, drains and rivers surrounding the tannery area in Erode district.

In this project soil samples and water samples from the area was collected on the regular surveys in the district and analysed for chromium. A mobility studies has been performed through batch experiments and a column study.

The soil showed surprisingly low values of chromium both in comparison with the results from Vellore district (a neighbour district) and with the national guidelines. The levels of Cr in the groundwater in Erode were with the exception of four samples higher than the stipulated level for drinking water, 50 µg/l. The mobility study showed that the absorption ability of the soil is poor and the mobility of chromium is high which promote further pollution of surrounding wells and rivers.