Determination of 226Ra, 228Ra and 40K in Soil from Felda Jengka-15 Oil Palm Plantation Masitah Aliasauthor Zaini Hamzahauthor Ahmad Saatauthor Muhamat Omarauthor Zakaria TajuddinauthorNaturally occurring radioisotopes such as 238U and 232Th are present in earth’s crust producing uranium and thorium daughters such as 226Ra and 228Ra. Radium is found at low level in soil, water, rocks, coal, plants and food. 40K also exist in the earth crust with a concentration of about 1.8 mg/kg or 13 pCi/g. In this study, the activity concentrations of 226Ra, 228Ra and 40K were determined in topsoil samples collected from 10 acres of oil palm plantation in FELDA Jengka 15, Maran District, Pahang Darul Makmur. 350 g of dried samples were ground and packed in a plastic container and allow to stabilize for at least three week before counting using gamma spectrometer with Germanium hyper pure detector (HPGe). The gamma spectra were analyzed using Genie 2000 for the activity concentrations of 226Ra and 228Ra and 40K. The results show the range of 10.5 – 35.3 Bq/kg for 226Ra, 11.4 – 42.8 Bq/kg for 228Ra and 11.3 – 156.6 Bq/kg for 40K. Q Science, Computer Science2005ANALISJournal