title: Assessment of environmental (226)Ra, (232)Th and (40)K concentrations in the region of elevated radiation background in Segamat District, Johor, Malaysia.
abstract: Extensive environmental survey and measurements of gamma radioactivity in the soil samples collected from Segamat District were conducted. Two gamma detectors were used for the measurements of background radiation in the area and the results were used in the computation of the mean external radiation dose rate and mean weighted dose rate, which are 276 nGy h(-1) and 1.169 mSv y(-1), respectively. A high purity germanium (HPGe) detector was used in the assessment of activity concentrations of (232)Th, (226)Ra and (40)K. The results of the gamma spectrometry range from 11 ± 1 to 1210 ± 41 Bq kg(-1) for (232)Th, 12 ± 1 to 968 ± 27 Bq kg(-1) for (226)Ra, and 12 ± 2 to 2450 ± 86 Bq kg(-1) for (40)K. Gross alpha and gross beta activity concentrations range from 170 ± 50 to 4360 ± 170 Bq kg(-1) and 70 ± 20 to 4690 ± 90 Bq kg(-1), respectively. These results were used in the plotting of digital maps (using ARCGIS 9.3) for isodose. The results are compared with values giving in UNSCEAR 2000.
authors.affiliation: Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johore Bahru, Johore, Malaysia. mouneersaleh@yahoo.com
authors.forename: Muneer Aziz
authors.initials: MA
authors.lastname: Saleh
authors.forename: Ahmad Termizi
authors.initials: AT
authors.lastname: Ramli
authors.forename: Yasser
authors.initials: Y
authors.lastname: Alajerami
authors.forename: Abubakar Sadiq
authors.initials: AS
authors.lastname: Aliyu
mesh_terms: D001417:Background Radiation; D040362:Geographic Information Systems; D062305:Geographic Mapping; D006801:Humans; D008296:Malaysia; D011197:Potassium Radioisotopes / Q000032:analysis*; D011829:Radiation Dosage; D011834:Radiation Monitoring; D011883:Radium / Q000032:analysis*; D018570:Risk Assessment; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013051:Spectrometry, Gamma; D013910:Thorium / Q000032:analysis*
chemical_list: D011197:Potassium Radioisotopes; D012990:Soil Pollutants, Radioactive; D013910:Thorium; D011883:Radium
keywords: (226)Ra; (232)Th; (40)K; Environmental; Isodose; Soil