title: NATURAL RADIOACTIVITY IN SEDIMENTS AND RIVER BANK SOIL OF KALLADA RIVER OF KERALA, SOUTH INDIA AND ASSOCIATED RADIOLOGICAL RISK.
abstract: The paper presents the activity concentrations of232Th,226Ra and40K in the sediments and river bank soil samples collected from the Kallada river environs of coastal Kerala. The radiological risks associated with these radionuclides were calculated. The samples were processed following standard procedure, and activity was counted using a high-efficiency 5″ × 5″ NaI (Tl) detector coupled to GSPEC gamma spectroscopy system. The mean values of measured activities of232Th,226Ra and40K in soil samples were found to be 98.1 ± 0.4, 60.3 ± 1.1 and 343.4 ± 1.8 Bq kg-1, respectively, which results in an average absorbed dose rate of 103 nGy h-1The corresponding values for sediment samples were found to be 88.0 ± 0.4, 48.6 ± 0.9 and 423.2 ± 2.0 Bq kg-1, respectively, with a resulting absorbed dose rate of 95 nGy h-1Radium equivalent activity, annual effective dose equivalent, the external and internal hazard indices were determined and compared with recommended limits. The results of the work provide background data on natural radioactive isotopes, which are useful in the assessment of human radiation exposure from natural environment. The accumulation of information on natural radiation is of great value for radiation protection.
authors.affiliation: Department of Studies in Physics, Mangalore University, Mangalagangothri 574199, India.
authors.forename: N
authors.initials: N
authors.lastname: Venunathan
authors.affiliation: Department of Studies in Physics, Mangalore University, Mangalagangothri 574199, India.
authors.forename: C S
authors.initials: CS
authors.lastname: Kaliprasad
authors.affiliation: Department of Studies in Physics, Mangalore University, Mangalagangothri 574199, India narayanay@yahoo.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Narayana
mesh_terms: D001417:Background Radiation; D005843:Geography; D005844:Geology; D007194:India; D011197:Potassium Radioisotopes / Q000032:analysis*; D016016:Proportional Hazards Models; D011834:Radiation Monitoring / Q000379:methods; D011851:Radioactivity; D011868:Radioisotopes; D011883:Radium / Q000032:analysis*; D045483:Rivers; D012987:Soil / Q000737:chemistry*; D012990:Soil Pollutants, Radioactive / Q000032:analysis; D013051:Spectrometry, Gamma; D013910:Thorium / Q000032:analysis
chemical_list: D011197:Potassium Radioisotopes; D011868:Radioisotopes; D012987:Soil; D012990:Soil Pollutants, Radioactive; D013910:Thorium; D011883:Radium