A preliminary study on herbal resources and their contamination with toxic heavy metals around pulicat lake, North Chennai, South east coast of India

In the present study, available herbal resources among the 96 villages around Pulicat Lake have been isolated, identified and located using global positioning system. Nearly 34 species of herbal plants belonging to 24 families have been observed in these villages. Analysis of 27 plant and 27 soil samples for concentrations of toxic heavy metals (cadmium, chromium and lead) reveals relatively higher concentrations of cadmium (4.81 μug mL ^-1) and chromium (1.472 μg mL ^-1) in the plants when compared with the soil samples. In addition to this, 22 water samples were collected and their physiochemical parameters like pH, salinity, chloride, carbonate and bicarbonate were analyzed. The results obtained indicate that pH and chloride do not seem to influence the bioavilability of toxic heavy metals. Further work is required to establish the relationships among physiochemical characters of the water, soil, accumulation of heavy metals in plants and their physiology.