Ecological risk assessment due to heavy metals prevalence in the sediments of Kayamkulam estuary, Kerala, India

Kayamkulam estuary, popular for inland fishing, in southern coast of India, Kerala lies in close proximity to major industrialisation set ups (mining companies). In the present baseline study, the heavy metal concentration in the sediments of this estuary were analysed to evaluate its pollution status and consequent risks to the environment. The extent of contamination was assessed in the 50 samples collected from 10 transects using Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP - OES), where the study found the mean concentration of metals to fall in the following order as: Fe [17,817.9 ppm] > Mn [117.35 ppm] > Cr [88.85 ppm] >Zn [53.68 ppm] > Ni [49.25 ppm] > Pb [20.02 ppm] > Co [13.34 ppm] > Cu [4.80 ppm]. Among these metals, Zn was found abundantly in the polluted sites, due to anthropogenic activities, such as mining and metallurgical processes. However, the values of the risk indices computed including [(Igeo), (PLI), (EF) and (PERI)], were low and reveals the present study area to be restrained from ecological risk. The outcome of the study, acting as baseline data will address pollution related problems in future, especially in biota.