An Experimental Study on the Direct Contamination Pathway of Elemental iodine Vapor $(I_2)$ for Rice Plants

벼에 대한 원소상 요오드 증기$(I_2)$의 직접오염경로 해석 실험

  • Choi, Y.H. (Korea Atomic Energy Research Institute) ;
  • Lim, K.M. (Korea Atomic Energy Research Institute) ;
  • Lee, C.M. (Korea Advanced Institute of Science and Technology) ;
  • Park, H.G. (Korea Atomic Energy Research Institute) ;
  • Park, D.W. (Korea Atomic Energy Research Institute) ;
  • Choi, G.S. (Korea Atomic Energy Research Institute) ;
  • Choi, H.J. (Korea Atomic Energy Research Institute) ;
  • Lee, H.S. (Korea Atomic Energy Research Institute) ;
  • Lee, C.W. (Korea Atomic Energy Research Institute)
  • Published : 2004.09.30

Abstract

Rice plants were exposed to $I_2$ vapor for 80 min at different growth stages in an exposure box to investigate the parameters concerning direct plant contamination. Deposition velocity $(m\;s^{-1})$ of the $I_2$ vapor for the straws was in the range of $1.4{\times}10^{-5}-1.3{\times}10^{-4}$ depending on the exposure time, being comparatively low during the earlier part of the plant growth. Ear deposition velocity was in the range of $2.5{\times}10^{-5}-6.7{\times}10^{-5}$. Whole-plant deposition velocity was in the range of $1.4{\times}10^{-5}-1.8{\times}10^{-4}$ with the highest from the exposure performed on Aug. 18 (7 d after the start of heading). The time-dependent variation generally decreased when the deposition velocity was normalized to the biomass density No noteworthy tendency in the deposition velocity was observed with regard to the temperature, sunlight and humidity. Translocation factor for the hulled seeds was $3.3{\times}10^{-5}-4.7{\times}10^{-4}$ with the highest from the Aug. 23 exposure. It was found that a leaf deposition even before the ear emergence resulted in a considerable seed translocation.

피폭상자 내에서 벼를 생육단계별로 80 분 간 $I_2$ 증기에 피폭시키고 작물체 직접오염 관련 인자를 조사하였다. $I_2$ 증기의 경엽부 침적속도$(m\;s^{-1})$는 피폭시기에 따라 $1.4{\times}10^{-5}-1.3{\times}10^{-4}$의 범위로 생육 전반기 피폭시 비교적 낮았다. 이삭 침적속도는 $2.5{\times}10^{-5}-6.7{\times}10^{-5}$의 범위였다. 전체 작물체에 대한 침적속도는 $1.4{\times}10^{-5}-1.8{\times}10^{-4}$의 범위로 8월 18일(출수 시작후 7일) 피폭시 가장 높았다. 침적속도를 생육밀도 기준으로 나타내면 시기에 따른 변이 정도가 대체로 감소하였다. 기온, 일광 및 습도에 대한 이렇다할 침적속도의 경향성은 관찰되지 않았다. 요오드의 현미 전류계수는 $3.3{\times}10^{-5}-4.7{\times}10^{-4}$의 범위로 8월 23일 피폭에서 가장 높았다. 출수전 경엽부에 침적한 요오드도 상당량 현미로 전류하는 것으로 나타났다.

Keywords

References

  1. M. J. Crick and G. S. Linsley, An Assessment of the Radiological Impact of the Windscale Reactor Fire, October, 1957, NRPB-R135, National Radiological Protection Board (1982)
  2. R. S. Daniels, 'Three Mile Island assessments,' in Environmental Radioactivity, Proc. the 19th Annual Meeting, 6-7 April, 1983, NCRP(1983)
  3. IPSN, The Tchernobyl Accident, Rapport IPSN 2/86, Revision 3(1986)
  4. S. Uchida, M. Sumiya, Y. Muramatsu, Y.Ohmomo, S. Yamaguchi, H. Obata and M. Umebayashi, 'Deposition velocity of gaseousI to rice grains,' Health Phys., 55,779-782(1988) https://doi.org/10.1097/00004032-198811000-00007
  5. M. I. Sheppard and J L. Hawkins, 'Iodine and microbial interactions in an organic soil,' J. Environ. Radioactivity, 29, 91-109(1995)
  6. P. G. Voilleque and J. H. Keller, 'Air-to-vegetation transport of $^{131}I$ as hypoiodous acid (HOI),' Health Phys., 40,91-94(1981)
  7. S. Uchida, Y. Muramatsu, M. Sumiya and Y. Ohmomo, 'Biological half-life of gaseous elemental iodine deposited onto rice grains, Health Phys., 60, 675-679(1991)
  8. R. K. Singhal, U. Narayanan and I. S. Bhat,' Laboratory evaluation of interception and translocation of $^{131}I$ in fenugreek and okra plants,' Health Phys., 67, 529-534(1994)
  9. Y. Nakamura, M. Sumiya, S. Uchida and Y. Ohmomo,'Transfer of gaseous iodine to rice plants,' J. Radiat. Res., 27, 171-182(1986)
  10. H. Noguchi and M. Murata, 'Physicochemical speciation of airborne $^{131}I$ in Japan from Chernobyl,' J. Environ Radioactivity, 7, 65-74(1988)
  11. R. J. Cox and C. J. Pickford, 'Determination of iodine-129 in vegetable samples by inductively coupled plasma mass spectrometry,' J. of Analatical Atomic Spectrometry, 7, 635-640(1992)
  12. J W. Olesik, Anal. Chem. Plasma Atomic Emission Spectroscopy, Boca ration, CRC press(1990)
  13. Y. Muramatsu, S. Uchida, M. Sumiya and Y. Ohmomo, 'Deposition velocity of gaseous organic iodine from the atmosphere to rice plants,' Health Phys., 71, 757-762(1996)
  14. C. A. Pelletier and J. D. Zimbrick, 'Kinetics of environmental radioiodine transport through the milk food chain,' in Environmental Surveillance in the Vicinity of Nuclear Facilities, Edited by W. C. Reinig, Springfield, IL : Charles C. Thomas(1970)
  15. G. Voigt, 'Physical transport and chemical and biological processes in agricultural systems,' in : Health Impacts of Large Releases of Radionuclides, Wiley, Ciba Foundation Symposium 203, 3-20(1997)
  16. P. J. Barry and A. C. Chamberlain, 'Deposition of iodine onto plant leaves from air,' Health Phys., 9, 1149-1157 (1963)
  17. 박종성, 조재영, 이은웅, 조동삼, 변종영, 이석순, 최관삼, 신제 작물생리학, 향문사(1991)
  18. Y. Nakamura and Y. Ohmomo, 'Factors used for the estimation of gaseous radioactive iodine intake through vegetation-II. Uptake of elemental iodine by spinach leaves,' Health Phys., 38, 315-320(1980)
  19. Y. H. Choi, K. M. Lim, D. Yu, H. G. Park, Y. G. Choi and C. M. Lee, 'Transfer pathways of $^{54}Mn,\;^{57}Co,\;^{85}Sr,\;^{103}RU\;and\;^{134}CS$ in rice and radish plants directly contaminated at different growth stages,' Annals of Nuclear Energy, 29, 429-446(2002)
  20. M. Sumiya, S. Uchida, Y. Muramatsu, Y. Ohmomo and H. 'Obata, Transfer of gaseous iodine from atmosphere to rough rice, brown rice and polished rice,' Hoken Butsuri, 22, 265-268(1987)
  21. IAEA, Handbook if Parameter Values for the Prediction of Radionuclide Transfer in Temperate Environments, Technical Report Series No. 364(1994)
  22. H. Müller and G. Pröhl, 'ECOSYS-87: A dynamic model for assessing radiological consequences of nuclear accidents,' Health Phys., 64, 232-252(1993)