[1] Malaysian Nucl Agcy Bangi, Radiat Proc Technol Div, Kajang 43000, Selangor, Malaysia
[2] Univ Kebangsaan Malaysia, Fac Engn & Built Environm, Dept Chem & Proc Engn, Bandar Baru Bangi 43650, Selangor, Malaysia
[3] Univ Putra Malaysia, Fac Sci, Dept Phys, Serdang 43400, Selangor, Malaysia
[4] Natl Inst Hlth, Inst Med Res, Environm Hlth Res Ctr, Shah Alam 40170, Selangor, Malaysia