Bioaccumulation of lead in gills and muscles of shellfish species from Pulicat lake, Tamil Nadu, India

Heavy metals are one of the most serious pollutants in the environment due to their toxicity, persistence and ability to concentrate along the food chain. Water bodies contaminated by heavy metals may lead to bioaccumulation in the food chain of an estuarine environment. Contamination of natural waters by heavy metals negatively affects aquatic biota and poses considerable environmental risks and concerns. In the present study, six species of shellfish, Fenneropenaeus indicus, Fenneropenaeus monodon, Fenneropenaeus semisulcatus, Scylla serrata, Clibanarius longitarsus and Meretrix casta in Pulicat lake, Tamil Nadu, India were analysed for the presence of lead in its gills and muscles from January 2011 to December 2012. The results showed seasonal variations in the uptake of lead. The highest concentration of lead was recorded in the gills of Meretrix casta (3.12μg/g) in the summer of 2012 and in the muscles of Fenneropenaeus indicus (2.15μg/g) during the premonsoon of 2011. In conclusion, the results of the present study indicated a mild to moderate accumulation of lead in the gills and muscles of shellfish species. Meretrix casta and Fenneropenaeus indicus showed a tendency to accumulate higher levels of lead than other shellfish species studied. At this rate, consumption of shellfish meat from Pulicat lake may lead to toxicity of man and other animals. Control measures are required to reduce lead pollution in Pulicat lake.