Heavy metals burden of Keenjhar Lake, District Thatta, Sindh, Pakistan

Detection of heavy metals (HMs) content from Keenjhar Lake water was carried out monthly from January to December, 2003. Zinc, chromium, copper, iron, manganese, nickel and cadmium were analyzed by dual mode of analytical methods flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry (FAAS and ETAAS) by multi element standard solution. The concentrations of zinc, chromium, copper, iron, manganese Nickel and cadmium were 1.4 to 104.3 μgL -1 , 1.28 to 4.9 μgL -1 , 0.6 to 7.3 μgL -1 , 2 to 45.6 μgL -1 , 0.2 to 6.7 μgL -1 , 3.54 to 39.5 μgL -1 and 1.0 to 4.3 μgL -1 , respectively. Zn 2+ , Cr + , Cu 2+ , Fe 2+ and Mn 2+ concentrations were recorded lower than those of permissible limits, whereas Ni + and Cd + were higher than those of permissible limits recommended by WHO (2004). Key words: Heavy metals, Keenjhar Lake, toxicity.