Ecotoxicity study of blood cockles (Anadara granosa) near Kg Wai ex-dumping site

Abstract

Marine blood cockles, Anadara granosa (A. granosa) can be commonly found along the coasts of western Malaysian Peninsular, and for this study it was collected from the shores of Kuala Perlis. Blood cockles are widely consumed by the general public and are receptive to heavy metals and known as bioaccumulators. On the other hand, leachate sediments were obtained from a former landfill site in Kg Wai, which eventually will be channeled to the western coasts via Sungai Perlis. The study was made to evaluate the heavy metal content (Cu, Pb, Ni, Zn, Cr) in both sediment and cockles and it’s toxicity potential for human consumption. Both specimens were processed and digested using strong acids, concentrated nitric acid, hydrogen peroxide and hydrochloric acid. The specimens were tested using atomic absorption spectrometer (AAS) and spectrophotometer (for Cr only). It is found that lead (Pb) is most prominent type of heavy metal due to it’s high content in both cockles and sediment ranging >15 mg/kg, compared to the rest of the metals. The lowest would be chromium for all the specimens, ranging <0.1 mg/kg or <0.1 mg/L. In conclusion, the levels of heavy metals in blood cockles in Kuala Perlis are still under safe levels for consumption, after being compared with the permitted dosage listed by Malaysian Food Regulation 1985, FAO/WHO (1984), US EPA (2000), US FDA (1993), FSANZ (2002) dan EU (2001).