Distribution of heavy metal concentrations in surface waters from ennore estuary, Tamil Nadu, India

An investigation was carried out in the Ennore creek for the assessment of heavy metal pollution pertaining to cadmium, copper, lead and zinc during January – December 2008 in all the four stations of post-monsoon, summer, pre-monsoon and monsoon. The data processed revealed that the concentrations of cadmium, copper, lead and zinc were above the permissible limits of coastal standards. The station wise levels of heavy metal concentration were in the order of station 4> station3> station 2> station 1. The seasonal variation of heavy metals observed in the Ennore estuary was maximum during summer and monsoon. Strong correlation (P<0.001, α=0.05) was found among the stations in the Ennore creek during post-monsoon, summer, pre-monsoon and monsoon. Among the stations in the Ennore estuary stations 3 and 4 were highly polluted and stations 1 and 2 was less polluted with cadmium, copper, lead and zinc.