Holothuria species as indicator of heavy metals pollution in Pulau Bidong, Terengganu

Abstract

This study aims at determining the heavy metals concentration and bioaccumulation factor (BAF) in Holothuria species in Pulau Bidong, Terengganu. Concentration of selected heavy metals (Zn, Fe, K, Mg, Pb, Cd, Co and Al) were analyzed in body wall, longitudinal muscle, respiratory tree, and digestive tract of Holothuria species in Pulau Bidong by using lCP-OES after the samples were digested with Microwave Digestion machine with l.5 mL of nitric acid. The heavy metals concentration are significantly different (p < 0.05) between body parts of Holothuria. K and Mg were the two highest metals with the concentration level of K was 5097.57 µg/g in body wall, 4333.04 µg/g in longitudinal muscle, 329.76 µg/g in respiratory tree and 5672.95 µg/g in digestive tract while concentration of Mg was 7858.32 µg/g in body wall, 6248.71 µg/g in longitudinal muscle, 7012.86 µg/g in respiratory tree and 9256.27 µg/g in digestive tract. Concentration of Pb was five times higher than the permissible levels of Malaysian Food Regulation while Cd was 2.4 times higher than permissible levels in world scale. Bioaccumulation factor of Holothuria species indicated Holothuria species is macroconcentrator with the values of bioaccumulation factor is higher than 2 in all four body parts. This indicates Holothuria species is suitable for biomonitoring of its environment. K and Mg are essential elements that require for daily biological processes of Holothuria which explains the high concentration of both elements in Holothuria species.