Concentration and Distribution of Heavy Metals (lead, Cadmium, Chromium, Copper, Nickel, Zinc) in Karacid Shore and Offshore Sediments

ABS11tACT: A study to measure the heavy metal pollution level in the sediment of coastal and offshore area indicates that high concentration of heavy metals were found around Manora channel and eastern coast of Karachi. In comparison with coastal areas, relatively low concentration of heavy metals was recorded in the offshore area. The result shows that sewage and industrial wastes are the main source of heavy metal poUution in the coastal area. The concentration of heavy metals in the sediments is as follows: Chromium 10.4-33.69, nickell3.3-47.6, lead 10.0-39.04, cadmium 0.08-0.21, zinc 7.4-73.2 and copper 9.44-18.56 mglkg. In the offshore areas strong correlation was observed between copper and organic carbon, and calcium carbonate and cadmium. In the shore area such correlation has been recorded among nickel, chromium, zinc, and chromium and copper. The Karachi. coast is viewed as moderately poUuted when compared to other continental coastal areas.