Identification of potentially toxic elements in crops and aquatic life at former tin mine sites in Perak.

This research aims to determine and identify Potentially Toxic Elements (PTEs) in crops and aquatic life grown and bred at several former tin mines in Perak. Samples were taken at Bidor, Bemban, Malim Nawar and Tronoh, which represents different conditions. The sites at Bemban and Bidor has agricultural and aquaculture activities which are referred to as active sites. Neither Malim Nawar nor Tronoh have any agricultural or aquaculture activities since the mining era, therefore representing former tin mines that are inactive. Generally, PTEs commonly found at mining sites are lead (Pb), zinc (Zn) and copper (Cu) (Ang et al. 1998). Due to the exposure to natural element and changes in climate, every sample will be taken in two conditions; (1) fish from inactive mining pond and fish bred by farmers at mining pools from the active site. (2) Crops that grow naturally near the mining pond and crops grown by farmers. The methodology for sample analysis was done by using wet digestion analysis with nitric acid and hydrochloric acid. Concentration of heavy metals was determined using flame atomic absorption spectrometry (FAAS). Pb concentration was found to be high in senduduk’s root at 57.62 mg/kg and in the muscle of Cichla sp. at 27.28 mg/kg. Zn concentration was also high in senduduk’s stem at 115.65 mg/kg and in the viscera of Cichla sp. at 203.65 mg/kg. The results also show that Pb and Zn levels are high regardless of whether it is from the active or inactive former tin mine site. The concentration of Pb and Zn found in all of the food crops and fish samples in this study were found to be above the safe limit issued in Food Act 1983.