Browsing by Author "Weerakkody, W.A.T.L."

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    Assessment of Background Frequency of Micronuclei Formation in Two Selected Populations in Sri Lanka.
    (In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Weerakkody, W.A.T.L.; Warnakulasuriya, D.T.D.; Williams, H.S.A.; Dabarera, M.D.; Rathnayake, R.M.N.P.; Rodrigo, B.K.S.K.; Wickremasinghe, A.R.
    This study assessed background frequency of micronuclei formation using biodosimetry in persons living in Norochcholai and Ragama in Sri Lanka. Biodosimetry, a technique used to assess exposure to radiation, is considered superior to physical dosimetry. It gives a clearer picture of individual variation of susceptibility to radiation and human risk assessment. This study establishes baseline levels of micronuclei formation in a Sri Lankan population to monitor possible radiation accidents that may occur at a nuclear power plant that was commissioned in nearby India recently. Biodosimetry has been used to detect external and internal exposure to ionising radiations in scenarios of accidental and occupational exposure wherever nuclear power plants are present. 96 healthy individuals from both sexes were selected for the study (in the age range of 20-59 years), comprising 50 from Norochcholai (area closest to the power plant) and 46 (matched for gender, age and life style) from Ragama (as a control). 10ml of venous blood was drawn and the cytokinesis–block micronuclei assay was performed, 1000 binucleate cells were assessed; the median spontaneous micronuclei formation was estimated. Background radiation was measured using an Automess dose rate meter 6150AD. There was no significant difference in the median MN frequency between the two sexes (p= 0.538). There was no significant difference between the median background frequency of micronuclei formation between the two study areas (p=0.539). Significantly higher radiation dose rate (measured by suevey meter) has been shown in Ragama area compared to Norochcholei area (Mann Whitney U= 217.00, p=0.000 ). There was no strong correlation between background radiation and MN frequency in both areas. The MN frequency can be used as a baseline to monitor exposure to radiation in the future. This is important for monitoring radiation hazards and will be useful in case of a nuclear accident.
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    Assessment of background radiation and frequency of micronuclei formation in two selected populations in Sri Lanka.
    (University of Kelaniya, 2019) Weerakkody, W.A.T.L.
    This study assessed background radiation and frequency of micronuclei formation in persons living in Norochcholai and Ragama. Ninety-six healthy individuals (20-59 years of age) from both sexes were selected for the study, comprising 50 from Norochcholai (area closest to the power plant) and 46 from Ragama (control). Ten milliliters of venous blood was drawn and the cytokinesis—block micronuclei assay was performed. Thousand binucleate cells were assessed; the median spontaneous micronuclei formation was estimated. Background radiation was measured using an Automess dose rate meter 6150AD. There was no significant difference in the median micronuclei (MN) frequency between the two sexes (p= 0.538) and the two study areas (p=0.539). There was no correlation between background radiation and MN frequency. Fifty-four water samples (26 from Norochcholai and 28 from Ragama) were analyzed by gamma spectrometry and radioactivity was not detected in any of the water samples. Fifty-one soil samples (25 from Norochcholai and 26 from Ragama) were analyzed by gamma spectrometry. The median radioactivity concentration (IQ range) of 232 Th, 40 K, 226Ra and 210Pb in Norochcholai were 50.0Bqkg-l (31.3-91.2), 99Bqkg-1 (84.0-111.3), 22Bqkg-l (14.3-40.3Bqkg-l) and 27Bqkg-l (23-44Bqkg-l) respectively; in Ragama, the median radioactivity concentrations (IQ range) of were significantly higher in Norochcholai than that of Ragama area exceþt for 40K.The gamma ray absorbed dose rates in soil samples of Norochcholai varied between 32.1 nGyh-l and 81.1 nGyh-l with an average of 51.2nGy h-l which is lower than the global average of 57 nGyh-l; in Ragama, this varied between 27.8-40. lnGyh-1. The mean Raeq of Norochcholai was 149.7 Bqkg-l. A radium equivalent activity above 370, the limit set by the Nuclear Energy Agency group of experts as safe to be used in building materials, was observed in 2 soil samples from Norochcholai. All the soil samples from Ragama had a Raeq below 370Bq/kg. The median Raeq was 73.7 Bq/kg. The median annual effective dose in Norochcholai was 0.062 mSv.y-l and in Ragama it was 0.040mSvy-l. They were within the safe limit of ImSv/y. Hex of all the samples were below I. Thus the soil from both the study areas are safe for human health. Pb were 38.4Bq/kg (26.4-52.1), 100.7Bq/kg (93.1-163.9), 11.7Bq/kg (10.1-16.3) and 25.9 Bq/kg (19.8-47.5) respectively. 232Th activity concentration in both were higher than the world average. Activity concentrations of all the radionuclides. The results of this study can be used as baseline data to monitor exposure to radiation in the selected population in the future. This is important for monitoring radiation hazards and will be useful in case of a nuclear accident. KEYWORDS: Background radiation, micronuclei, Nuclear accident, baseline data, gamma spectrometry