DETERMINATION OF NATURAL RADIOACTIVITY AND HEAVY METALS AT THE FORMER MINING SITE OF KOLEJ UNIVERSITI ISLAM ANTARABANGSA SELANGOR (KUIS) LAKE

An ex-mining site has created an undesirable effect on the environment, such as the destruction of plants and contamination. Thus, this study was conducted to determine the natural radioactivity and heavy metal presence in the ex-mining site at Kolej University Islam Antarabangsa Selangor (KUIS) lake. Both parameters were measured using gamma spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the concentrations of U (0.44 ± 0.31 Bq/L), Th (0.04 ± 0.02 Bq/L), 226 Ra (0.19 ± 0.11 Bq/L), and K (0.62 ± 0.37 Bq/L) in water samples were below the recommended values by the World Health Organization (WHO) for drinking water source, which implied the safe consumption of the water. However, the presence of U, Th, 226 Ra, and K in sediment samples exceeded the limit proposed by UNSCEAR, with the radioactivity of 49.1 ± 18.8 Bq/kg, 102.3 ± 3.3 Bq/kg, 133.2 ± 18.8 Bq/kg, and 297.1 ± 25.7 Bq/kg, respectively. For heavy metal determination, zinc was found in the sediment with the highest concentration (17.34 ± 15.79 mg/kg) compared to other heavy metals, while the concentration of arsenic was highest in water with 0.58 ± 0.26 μg/L. All hazard indices were found to be below the safety limit except for the gamma index of 1.6 ± 0.7 Bq/kg and 104.1 ± 48.4 nGy/h for the gamma dose rate.