Evaluation of Heavy Metal Contamination in Surface Soil around Industrial Area, Tamil Nadu, India

Impact of anthropogenic activities of man and his environment as a result of the growing rate of industrialisation in Tamilnadu, India is of a great concern. The objective of this research was to evaluate the physical properties and heavy metal concentration of soil in different industrial areas. Soil samples were collected from seven industries like welding, cement, steel, printing, textile, paint and tannery which releases heavy metals to environment. Electrical Conductivity (EC), pH, Cation Exchange Capacity (CEC), Organic Matter (OM), Organic Carbon (OC) and heavy metals viz. Cu, Mn, Cr, Pb, Zn and Fe were analysed. Except tannery and steel industry all samples have alkaline pH. The maximum EC 6.41 dSm was noticed in the soil sample collected from textile industry. The results showed that very high level of OC and OM were found in the soil contaminated by printing industry. The soil samples contaminated with cement and printing industries pollutants showed high CEC 26.4 and 38.7 m.eq /100g of soil. Different metals were found to be in higher level in different areas. High level of copper 28.9 ppm is noticed in sample collected from Tannery. The manganese level in increasing order is Textile < Cement < Steel < Painting < Tannery < Welding. The maximum level of iron 46.6 ppm and zinc 13.6 ppm is noticed in sample collected near welding industry. The soil sample of tannery industry showed high level of chromium 32.5 ppm and lead 15.7 ppm. However, comparing these concentrations with those obtained from locations of industrial activity, relatively high levels of heavy metals were recorded, with different industries. Considering all the heavy metals obtained at the study area, Zn, Pb and Cr dominated in all the investigated zones of high industrial impact. This is attributed to the indiscriminate disposal of industrial waste as well as anthropogenic point source contamination. The extremely high contents of the heavy metals generally recorded at the study area are terribly alarming in terms of environmental pollution. Therefore, the inhabitants (mostly children) and the numerous workers, who reside and work at such polluted environment, are at serious risk of heavy metal toxicity and awareness needs to be created as such.