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Natalia Shagina , Evgenia Tolstykh and Marina Degteva

Evaluation of In Utero Doses from Maternal Ingestion of Strontium Radioisotopes at the Techa River. Natalia Shagina , Evgenia Tolstykh and Marina Degteva Urals Research Center for Radiation Medicine, Chelyabinsk, Russia John Harrison and Tim Fell Health Protection Agency, Chilton, Didcot, UK

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Natalia Shagina , Evgenia Tolstykh and Marina Degteva

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  1. Evaluation of In Utero Doses from Maternal Ingestion of Strontium Radioisotopesat the Techa River Natalia Shagina, Evgenia Tolstykh and Marina Degteva Urals Research Center for Radiation Medicine, Chelyabinsk, Russia John Harrison and Tim FellHealth Protection Agency, Chilton, Didcot, UK Wesley Bolch and Matthew Maynard University of Florida, Gainesville, USA

  2. Contamination of the Techa River in 1950s (Southern Urals, Russia)

  3. Pathways of internal exposure for the Techa River population River water – an essential source of drinking water in most villages Locally produced foodstuffs – milk, meat, vegetables, etc. Muslyumovo (78 km from release site)

  4. Maternal ingestion of Sr isotopes lead to in utero exposure of offspring Sr isotopes easily transfer through placenta during pregnancy and are retained in foetal tissues (predominantly skeleton)

  5. Methodology for in utero dose evaluation consists of the three major steps Quantification of time dependent amount of Sr isotopes ingested by a mother Quantification of retention of Sr isotopes in foetal tissues as a result of transfer from a mother Quantification of the energy absorbed in foetal bone marrow due to nuclear disintegrations in mineralized foetal bone INTAKEFUNCTION BIOKINETICMODEL DOSIMETRICMODEL

  6. Reconstruction of 89,90Sr intakes for the Techa River residents 90Sr - from numerous 90Sr measurements in human teeth and whole body (Tolstykh et al 2011) 89Sr - using 89Sr-to-90Sr ratio in river water (Shagina et al 2012) Comparison of dietary 90Sr intake at the Techa River and in the United Kingdom(PapworthandVennart 1984)

  7. Maternal intakes of Sr radioisotopes Intake of 89,90Sr during pregnancy is increased due to increased nutritional and water requirements Intake of 89,90Sr by mothers in 1950-1952(period of max intake)

  8. Biokinetic model for strontium ICRP-88 biokinetic model was adapted to the Techa River population by fitting to Russian and Urals data Details are in presentation P02.81 by Shagina et al.

  9. Dosimetry models for in utero exposure Phantoms for 11.5 and 21 week foetuses were developed at University of Florida from CT and MRI images of foetal specimens These phantoms were used to develop a series of all gestation ages (12-38 weeks) 11.5 week foetus image 11.5 week foetus phantom 21 week foetus image 21 week foetus phantom

  10. Age-dependent dose per nuclear transformation for studied radionuclides Dose in spongiosa is a surrogate for dose absorbed in foetal bone marrow

  11. In-utero red bone marrow dose calculated for children born in Muslyumovo in 1950-1952

  12. ICRP models were recommended for radiation protection of a foetus Models developed in this study are more appropriate for epidemiological studies Comparison with estimates obtained with ICRP Publication 88 models

  13. Application of the developed methodology in risk assessment Methodology and models developed in this study provide dosimetric support for evaluation of solid cancer and leukaemia risk from protracted exposure in the Techa River in utero Exposed Cohort The Cohort comprises 12,000 offspring with most cohort members exposed to ingested radionuclides (mainly Sr isotopes). Study of this cohort may provide valuable information on risks from exposures to internal emittersin early human life

  14. Acknowledgements Our research leading to these results received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 249675 I would like to thank the Russian IRPA Associate Society for nominating me for a Young Professional Prize Thank you for your attention!

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