**6. Radiological hazard of 129I for man**

Transport pathways of iodine to human are ingestion and inhalation. Iodine present in food is adsorbed into blood in small intestine – inhaled iodine from the air is also transferred into blood. More than 80 % of iodine absorbed into the blood is concentrated in the thyroid gland, which is therefore the target organ of iodine – also radioactive 129I. Due to low beta and gamma energy of 129I and long half-life the radiation toxicity of 129I is mainly related to long term and low dose internal exposure of the thyroid to the beta radiation of 129I. An average iodine content in human thyroid is 10−15 mg. 129I and 127I are taken up by thyroid indiscriminately. The highest reported 129I/127I ratio was 10-4 in close vicinity of NFRP, which corresponds to 10-6 g or 6.64 Bq at 10 mg stable iodine content in thyroid. The corresponding annual radiation dose to thyroid would be 0.1 mSv year-1, which is 2.5 times higher than the dose regulation limit of 0.04 mSv year-1 set by the U.S. NRC for combined beta and photon emitting radionuclide to the whole body or any organ (Hou et. al., 2009). An annual thyroid equivalent dose of 1 mSv, which is comparable to the level of natural back-ground radiation, would only be reached by ratios exceeding 1.5 · 10-3 (Michel, 1999). Current concentrations of 129I in the environment do not represent any radiological hazard for man, even in the vicinity of nuclear fuel reprocessing plants. But to assess environmental impact and potential risk and consequences during long-term exposition information on the distribution and radionuclide species, speciation analysis, influencing the mobility, biological uptake and accumulation of radionuclides is needed (Salbu, 2007). Speciation analysis provides crucial information for evaluation of radionuclide transport mechanism in the environment and to the human body and accurate risk assessments (Hou et al., 2009).

### **7. Conclusion**

Anthropogenic 129I considerable enriched pre-nuclear environmental levels. Presently the main sources of 129I in the environment are nuclear fuel reprocessing plants (NFRP). Global distribution of 129I is not uniform – concentrations are elevated near NFRP – but anthropogenic 129I was detected in remote areas such as Antarctic.

Before the onset of nuclear age 129I and 127I were in equilibrium. Analysis of pre-nuclear material and deep layer of marine sediment gave the best estimated value for natural 129I/127I ratio in surface reservoirs to be (1.5 ± 0.15) · 10-12.

In transport and exchange of 129I among different compartments marine and soil ecosystems influenced by present biota – microorganisms play major role. Biogeochemical cycling of iodine is influenced by its strong association with organic material – ocean is the main reservoir of mobile iodine, where it is rapidly exchanged between biota, hydrosphere and atmosphere.

#### **8. References**

Aldahan, A., Alfimov, V., Possnert, G. (2007a). 129I anthropogenic budget: Major sources and sinks. *Applied Geochemistry,* Vol. 22, No. 3, pp. (606-618), ISSN 0883-2927

129I can be used to reconstruct 131I dose to thyroids. This method is limited only to areas that were relatively strong contaminated by fallout from Chernobyl like areas in Ukraine and

Transport pathways of iodine to human are ingestion and inhalation. Iodine present in food is adsorbed into blood in small intestine – inhaled iodine from the air is also transferred into blood. More than 80 % of iodine absorbed into the blood is concentrated in the thyroid gland, which is therefore the target organ of iodine – also radioactive 129I. Due to low beta and gamma energy of 129I and long half-life the radiation toxicity of 129I is mainly related to long term and low dose internal exposure of the thyroid to the beta radiation of 129I. An average iodine content in human thyroid is 10−15 mg. 129I and 127I are taken up by thyroid indiscriminately. The highest reported 129I/127I ratio was 10-4 in close vicinity of NFRP, which corresponds to 10-6 g or 6.64 Bq at 10 mg stable iodine content in thyroid. The corresponding annual radiation dose to thyroid would be 0.1 mSv year-1, which is 2.5 times higher than the dose regulation limit of 0.04 mSv year-1 set by the U.S. NRC for combined beta and photon emitting radionuclide to the whole body or any organ (Hou et. al., 2009). An annual thyroid equivalent dose of 1 mSv, which is comparable to the level of natural back-ground radiation, would only be reached by ratios exceeding 1.5 · 10-3 (Michel, 1999). Current concentrations of 129I in the environment do not represent any radiological hazard for man, even in the vicinity of nuclear fuel reprocessing plants. But to assess environmental impact and potential risk and consequences during long-term exposition information on the distribution and radionuclide species, speciation analysis, influencing the mobility, biological uptake and accumulation of radionuclides is needed (Salbu, 2007). Speciation analysis provides crucial information for evaluation of radionuclide transport mechanism in the environment and to the human body and accurate risk assessments (Hou et al., 2009).

Anthropogenic 129I considerable enriched pre-nuclear environmental levels. Presently the main sources of 129I in the environment are nuclear fuel reprocessing plants (NFRP). Global distribution of 129I is not uniform – concentrations are elevated near NFRP – but

Before the onset of nuclear age 129I and 127I were in equilibrium. Analysis of pre-nuclear material and deep layer of marine sediment gave the best estimated value for natural

In transport and exchange of 129I among different compartments marine and soil ecosystems influenced by present biota – microorganisms play major role. Biogeochemical cycling of iodine is influenced by its strong association with organic material – ocean is the main reservoir of mobile iodine, where it is rapidly exchanged between biota, hydrosphere and

Aldahan, A., Alfimov, V., Possnert, G. (2007a). 129I anthropogenic budget: Major sources and sinks. *Applied Geochemistry,* Vol. 22, No. 3, pp. (606-618), ISSN 0883-2927

anthropogenic 129I was detected in remote areas such as Antarctic.

129I/127I ratio in surface reservoirs to be (1.5 ± 0.15) · 10-12.

Belarus (Michel et al., 2005; Straume et al., 2006).

**6. Radiological hazard of 129I for man** 

**7. Conclusion** 

atmosphere.

**8. References** 


The Potential Of I-129 as an Environmental Tracer 385

Hou, X.L., Yan, X.J. (1998). Study on the concentration and seasonal variation of inorganic

Hou, X., Dahlgaar., H., Rietz, B., Jacobsen, U., Nielsen, S.P., Aarkrog, A. (1999).

activation analysis. *Analyst,* Vol. 124, No. 7, pp. (1109-1114), ISSN 0003-2654 Hou, X.L., Dahlgaard, H, Nielsen, S.P. (2000a). Iodine-129 time series in Danish, Norwegian

Hou, X., Dahlgaard, H., Nielsen, S.P., Ding, W. (2000b). Iodine-129 in human thyroids and

Hou X., Yan X., Chai C. (2000c). Chemical species of iodine in some seaweeds II. Iodine-

Hou, X., Dahlgaard, H., Nielsen S.P. (2001). Chemical speciation analysis of 129I in seawater

Hou X., Malencheko A.F., Kucera J., Dahlgaard H., Nielsen S.P. (2003a). Iodine-129 in

Hou, X.L., Fogh, C.L., Kucera, J., Andersson, K.G., Dahlgaard, H., Nielsen, S.P. (2003b).

Hou, X. (2004). Application of 129I as an environmental tracer. *Journal of Radioanalytical and* 

Hou, X.L., Aldahan, A., Nielsen, S.P., Possnert, G., Nies, H., Hedfors, J. (2007). Speciation of

Hou, X., Hansen, V., Aldahan, A., Possnert, G., Lind, O.C., Lujaniene, G. (2009). A review on

Hou, X., Zhou, W., Chen, N., Zhang L., Liu, Q., Lou, M., Fan, Y., Liang, W., Fu, Y. (2010).

*Analytical Chemistry,* Vol. 82, No. 18, pp. (7713-7721), ISSN 0003-2700 Izmer, A.V., Boulyga, S.F., Becker, J.S. (2003). Determination of 129I/127I isotope ratios in

*Nuclear Chemistry,* Vol. 262, No. 1, pp. (67-75), ISSN 0236-5731

*Chimica Acta,* Vol. 632, No. 2, pp. (181-196), ISSN 0003-2670

3, pp. (141-156), ISSN 0048-9697

ISSN 0048-9697

ISSN 0265-931X

0048-9697

ISSN 0013-936X

0267-9477

*Shelf Science,* Vol. 51, No. 5, pp. (571-584), 0272-7714

Vol. 245, No. 3, Vol. (461-467), ISSN 0236-5731

302, No. 1-3, pp. (63-73), ISSN 0048-9697

elements in 35 species of marine algae. *Science of the Total Environment,* Vol. 222, No.

Determination of 129I in seawater and some environmental materials by neutron

and northwest Greenland coast and the Baltic Sea by seaweed. *Estuarine Coastal and* 

seaweed in China. *Science of the Total Environment,* Vol. 246, No. 2-3, pp. (285-291),

bound biological macromolecules. *Journal of Radioanalytical and Nuclear Chemistry,*

and a preliminary investigation to use it as a tracer for geochemical cycle study of stable iodine. *Marine Chemistry,* Vol. 74, No. 2-3, pp. (145-155), ISSN 0304-4203 Hou, X.L., Dahlgaard, H., Nielsen, S.P., Kucera, J. (2002). Level and origin of Iodine-129 in

the Baltic Sea. *Journal of Environmental Radioactivity,* Vol. 61, No. 3, pp (331-343),

thyroid and urine in Ukraine and Denmark. *Science of the Total Environment,* Vol.

Iodine-129 and Caesium-137 in Chernobyl contaminated soil and their chemical fractionation. *Science of the Total Environment,* Vol. 308, No., 1-3, pp. (97-109), ISSN

I-129 and I-127 in seawater and implications for sources and transport pathways in the North Sea. *Enironmental Science and Technology,* Vol. 41, No. 17, pp. (5993-5999),

speciation of iodine-129 in the environmental and biological samples. *Analytica* 

Determination of Ultralow Level I-129/I-127 in Natural Samples by Separation of Microgram Carrier Free Iodine and Accelerator Mass Spectrometry Detection.

liquid solutions and environmental soil samples by ICP-MS with hexapole collision cell. *Journal of Analytical Atomic Spectrometry,* Vol. 18, No. 11, pp. (1339-1345), ISSN

transport of nuclear fuel-reprocessing wastes from mid-to-high latitudes in the Atlantic Ocean. *Marine Biology,* Vol. 131, No. 3, pp. (391-399), ISSN 0025-3162


*Applied Geochemistry,* Vol. 18, No. 12, pp. (1867-1873), ISSN 0883-2927 Edwards, R.R. (1962). Iodine-129: Its Occurrenice in Nature and Its Utility as a Tracer.

*Research B,* Vol. 268, No. 7-8, pp. (1139-1141), ISSN 0168-583X

Englund, E., Aldahan, A., Hou X.L., Possnert, G., Söderström C. (2010a). Iodine (129I and 127I)

Englund, E., Aldahan, A., Hou, X.L., Petersen, R., Possnert, G. (2010b). Speciation of iodine

Fehn, U., Snyder, G., Egeberg, P.K. (2000a). Dating of Pore Waters with 129I: Relevance for

Fehn, U., Snyder, G. (2000b). 129I in the Southern Hemisphere: Global redistribution of an

Fehn, U., Moran, J.E., Snyder, G.T., Muramatsu, Y. (2007). The initial 129I/I ratio and the

Frechou, C., Calmet, D., Bouisset, P., Piccot, D., Gaudry, A., Yiou, F., Raisbeck, G. (2001). 129I

Frechou, C., Calmet, D. (2003). 129I in the environment of the La Hague nuclear fuel

Fuge, R. (2005). Soils and iodine deficiency, In: *Essentials of Medical Geology,* O. Selinus (Ed.), 417-433, Elsevier, ISBN 0-12-636341-2, Amsterdam, The Netherlands. Gilfedder, B.S., Lai, S.C., Petri, M., Biester, H., Hoffmann, T. (2008). Iodine speciation in rain,

Gomez-Guzman, J.M., Lopez-Gutierrez, J.M., Holm, E., Pinto-Gomez, A.R. (2011). Level and

Gudelis, A., Lukšiene, B., Druteikiene, R., Gvozdaite, R., Kubarevičiene, V. (2006).

Hou X., Chai C., Qian Q., Yan X., Fan X. (1997). Determination of chemical species in some

*Physics Research B,* Vol. 259, No. 1, pp. (496-5029), ISSN 0168-583X

*Science,* Vol. 137, No. 3533, pp. (851-853)

*B,* Vol. 268, No. 7-8, ISSN 0168-583X

172, No. 1-4, pp. (366-371), ISSN 0168-583X

*Nuclear Chemistry*, Vol. 249, No. 1, pp. (133-138)

Vol. 70, No. 1-2, pp. (43-59)

6084), ISSN 1680-7316

9697

Katowice, Poland, October 17-21, 2005

0036-8075

transport of nuclear fuel-reprocessing wastes from mid-to-high latitudes in the Atlantic Ocean. *Marine Biology,* Vol. 131, No. 3, pp. (391-399), ISSN 0025-3162 Duffa, C., Frechou, C. (2003). Evidence of long-lived I and Pu isotopes enrichment in

vegetation samples around the Marcoule nuclear reprocessing plant (France).

in aerosols from northern Europe. *Nuclear Instruments and Methods in Physics* 

(127I and 129I) in lake sediments. *Nuclear Instruments and Methods in Physics Research* 

the Origin of Marine Gas Hydrates. *Science,* Vol. 289, No. 5488,pp. (2332-2335), ISSN

anthropogenic isotope. *Nuclear Instruments and Methods in Physics Research B,* Vol.

presence of 'old' iodine in continental margins, *Nuclear Instruments and Methods in* 

and 129I/127I ratio determination in environmental biological samples by RNAA, AMS and direct γ-X spectrometry measurements. *Journal of Radioanalytical and* 

reprocessing plant-from Sea to land. *Journal of Radioanalytical and Nuclear Chemistry,*

snow and aerosols. *Atmospheric Chemistry and Physics,* Vol. 8, No. 20, pp. (6069-

origin of 129I and 137Cs in lichen samples (*Cladonia alpestris*) in central Sweden. *Journal of Environmental Radioactivity,* Vol. 102, No. 2, pp. (200-205), ISSN 0265-931X

Applications of LSC for the determination of some radionuclides in waste matrices from the Ignalina NPP. *Proceedings of the 2005 International Liquid Scintillation Conference,* Arizona Board on behalf of the University of Arizona, pp. (343-353),

seaweeds (I). *Science of Total Environment,* Vol. 204, No. 3, pp. (215-221), ISSN 0048-


The Potential Of I-129 as an Environmental Tracer 387

Moran, J.E., Fehn, U., Teng, R.T.D. (1998). Variations in 129I/127I ratios in recent marine

Muramatsu, Y, Yoshida, S. (1995). Determination of 129I and 127I in environmental samples by

Muramatsu, Y., Yoshida, S., Uchida, S., Hasebe, A. (1996). Iodine desorption from rice

Muramatsu, Y., Wedepohl, K.H. (1998). The distribution of iodine in the earth's crust.

Muramatsu, Y., Yoshida, S. (1999). Effects of microorganisms on the fate of iodine in the soil environment. *Geomicrobiological Journal,* Vol. 16, No. 1, pp. (85-93), ISSN 0149-0451 Muramatsu, Y., Fehn, U., Yoshida, S. (2001). Recycling of iodine in fore-arc areas: evidence

Muramatsu, Y., Takada, Y., Matsuzaki, H., Yoshida, S. (2008). AMS analysis of 129I in

Osterc, A., Stibilj, V. (2005). Measurement uncertainty of iodine determination in

Osterc, A., Jaćimović, R., Stibilj, V. (2007). Development of a method for 129I determination

Osterc, A., Stibilj, V. (2008). 127I and 129I/127I isotopic ratio in marine alga *Fucus virsoides* from

Parry, S.J., Bennett, B.A., Benzig, R., Lally, A.E., Birch, C.P., Fulker, M.J. (1995). The

*Quaternary Geochronology,* Vol. 3, No. 3, pp. (291-297), ISSN 1871-1014 Orre, S., Smith, J.N., Alfimov, V., Bentsen, M. (2010). Simulating transport of 129I and

*Mechanisms,* Vol. 10, No. 1-2, pp. (213-233), ISSN 1567-7419

*Chemical Geology,* Vol. 147, No. 3-4, pp. (201-216), ISSN 0009-2541

1-2, pp. (193-203), ISSN 0009-2541

No. 1, pp. (149-159), ISSN 0236-5731

iodine brines in Chiba, Japan

10, No. 5, pp. (235-240), ISSN 0949-1775

2, pp. (273-283), ISSN 1318-0207

(757-765), ISSN 0265-931X

5731

6979

sediments: evidence for a fossil organic component. *Chemical Geology,* Vol. 152, No.

neutron activation analysis (NAA) and inductively coupled plasma mass spectrometry (ICP-MS). *Journal of Radioanalitycal and Nuclear Chemistry,* Vol. 197,

paddy soil. *Water, Air and Soil Pollution,* Vol. 86, No. 1-4, pp. (359-371), ISSN 0049-

from the iodine brines in Chiba, Japan. *Earth and Planetary Science Letters,* Vol. 192, No. 4, pp. (583-593), ISSN Recycling of iodine in fore-arc areas: evidence from the

Japanese soil samples collected from background areas far from nuclear facilities.

idealized tracers in the northern North Atlantic Ocean. *Environmental Fluid* 

radiochemical neutron activation analysis. *Accreditation and Quality Assurance,* Vol.

using radiochemical neutron activation analysis. *Acta Chimica Slovenica,* Vol. 54, No.

the North Adriatic Sea. *Journal of Environmental Radioactivity,* Vol. 99, No. 4, pp.

determination of 129I in milk and vegetation using neutron activation analysis. *Science of the Total Environment,* Vol. 173-174, No. 1, pp. (351-360), ISSN 0236-5731 Pham, M.K., Betti, M., Povinec, P.P., Benmansour, M., Bojanowski, R., Bouisset, P., Calvo,

E.C., Ham, G.J., Holm, E., Hult, M., Ilchmann, C., Kloster, M., Kanisch, G., Köhler, M., La Rosa, J., Legarda, F., Llauradó, M., Nourredine, A., Oh, J.-S., Pellicciari, M., Rieth, U., Rodriguez y Baena, A.M., Sanchez-Cabeza, J.A., Satake, H., Schikowski, J., Takeishi, M., Thebault, H., Varga, Z. (2010). A new reference material for radionuclides in the mussel sample from the Mediterranean Sea (IAEA-437). *Journal of Radioanalyticaland and Nuclear Chemistry,* Vol. 283, No. 3, pp. (851-859), ISSN 0236-


Izmer, A.V., Boulyga, S.F., Zoriy, M.V., Becker, J.S. (2004). Improvement of the detection

Keogh, S.M., Aldahan, A., Possnert, G., Finegan, P., Vintro, L. L., Mitchell P.I. (2007). Trends

Kutschera, W., Fink, D., Paul, M., Hollos, G., Kaufman, A. (1988). Measurement of the I-

Leblanc, C., Colin, C., Cosse, A., Delage, L., La Barre, S., Morin, P., Fiévet, B., Voiseux, C.,

Lefevre, O., Bouisset, P., Germain, P., Barker, E., Kerlau, G., Cagnat, X. (2003). Self-

Leiterer, M., Truckenbrodt, D., Franke, K. (2001). Determination of iodine species in milk

Lopez-Gutierrez, J.M. Garcia-Leon, M., Schnabel, Ch., Suter, M., Synal, H.A., Szidat, S.,

Lu, Z., Fehn, U., Tomaru, H., Elmore, D., Ma, X. (2007). Reliability of 129I/I ratios produced

Michel, R. (1999). Long-lived radionuclides as tracers in terrestrial and extraterrestrial matter. *Radiochimica Acta,* Vol. 87, No. 1-2, pp. (47-73), ISSN 0033-8230 Michel, R., Handl, J., Ernst, T., Botsch, W., Szidat, S., Schmidt, A., Jakob, D., Beltz, D.,

Mironov, V., Kudrjashov, V., Yiou, F., Raisbeck G.M. (2002). Use of I-129 and Cs-137 in soils

*Research and Technology,* Vol. 213, No. 2, pp. (150-153), ISSN 1438-2377 Li, K., Vogel, E., Krähenbühl, U. (2009). Measurement of I-129 in environmental samples by

*Spectrometry,* Vol. 19, No. 9, pp. (1278-1280), ISSN 0267-9477

*Radioactivity,* Vol 95, No. 1, pp. (23-38), ISSN 0265-931X

*Research A,* Vol. 506, No. 1-2, pp. (173-185), ISSN 0168-9002

ISSN 0281-1847

pp. (1773-1785), ISSN 0300-9084

(453-458), ISSN 0033-8230

259, No. 1, pp. (359-364), ISSN 0168-583X

No. 1-3, pp. (35-55), ISSN 0048-9697

ISSN 0048-9697

0265-931X

limit for determination of 129I in sediments by quadrupole inductively coupled plasma mass spectrometer with collision cell. *Journal of Analytical Atomic* 

in the spatial and temporal distribution of 129I and 99Tc in coastal waters sorrouding Ireland using *Fucus vesiculosus* as bio-indicator. *Journal of Environmental* 

129/I-131 ratio in Chernobyl fallout. *Physica Scripta,* Vol. 37, No. 2, pp. (310-313),

Ambroise, Y., Verhaeghe, E., Amouroux, D., Donard, O., Tessier, E., Potin, P. (2006). Iodine transfers in the coastal marine environment: the key role of brown algae and of their vanadium-dependent haloperoxidases. *Biochimie*, Vol. 88, No. 11,

absorption correction factor applied to 129I measurement by direct gamma-X spectrometry for *Fucus serratus* samples. *Nuclear Instruments and Methods in Physics* 

using ion chromatographic separation and ICP-MS detection. *European Food* 

ICP-CRI-QMS: possibilities and limitations. *Radiochimica Acta,* Vol. 97, No. 8, pp.

Garcia-Tenorio, R. (2004). Relative influence of 129I sources in a sediment core from the Kattegat area. *Science of The Total Environment,* Vol. 323, No. 1-3, pp. (195-210),

from small sample masses. *Nuclear Instruments and Methods in Physics Research B,* ol.

Romantschuk, L.D., Synal, H.A., Schnabel, C., López-Gutiérrez, J.M. (2005). Iodine-129 in soils from Northern Ukraine and theretrospective dosimetry of the iodine-131 exposure after the Chernobyl accident. *Science of the Total Environment,* Vol. 340,

for the estimation of I-131 deposition in Belarus as a result of the Chernobyl accident. *Journal of Environmental Radioactivity,* Vol. 59, No. 3, pp. (293-307), ISSN


The Potential Of I-129 as an Environmental Tracer 389

Straume, T., Anspaugh, L.R., Marchetti, A.A., Voigt, G., Minenko, V., Gu, F., Men, P.,

Stutz, J., Hebestreit K., Alicke, B., Platt, U. (2000). Chemistry of Halogen Oxides in the

Suarez, J. A., Espartero, A. G., Rodriguez, M. (1996). Radiochemical analysis of 129I in

Suzuki, T., Kitamura, T., Kabuto, S., Togawa, O., Amano, H. (2006). High sensitivity

Suzuki, T., Kabuto, S., Amano, H., Togawa, O. (2008). Measurement of iodine-129 in

Snyder, G.T., Riese, W.C., Franks, S., Fehn, U., Pelzmann, W.L., Gorody, A.W., Moran, J.E.

Snyder, G., Poreda, R., Fehn, U., Hunt, A. (2003b). Sources of nitrogen and methane in

Snyder, G., Fehn, U. (2004). Global distribution of I-129 in rivers and lakes: implications for

Szidat, S., Schmidt, A., Handl, J., Jakob, D., Botsch, W., Michel, R., Synal, H.A., Schnabel, C.,

Szidat, S., Schmidt, A., Handl, J., Jakob, D., Michel, R., Synal, H.A., Suter, M. (2000b).

Tendow, Y. (1996). Nuclear Data Sheets for A = 129. *Nuclear Data Sheets,* Vol. 77, No. 4, pp.

UNSCEAR Report (2000). Sources and effects of ionizing radiation, Vol. I: Sources, Annex A:

dela Vieja, A., Calero, M., Santisteban, P., Lamas, L. (1997). Identification and quantitation of

*Cosmochimica Acta,* Vol. 67, No. 23, pp. (4529-4544), ISSN 0016-7037

*Research Section B,* Vol. 223-224, pp. (579-586), ISSN 0168-583X

172, No. 1-4, pp. (699-710), ISSN 0168-583X

*Health Physics,* vol. 91, No. 1, pp. (7-19), ISSN 0017-9078

*Geochronology,* Vol. 3, No. 3, pp. (268-275), ISSN 1871-1014

*Atmospheric Chemistry,* Vol. 34, No. 1, pp. (65-85)

Vol. 369, No. 2-3, pp. (407-410), ISSN 0168-9002

3131

No. 9001, ISSN 1525-2027

(45-50), ISSN 0236-5731

of Atomic Radiation, pp. 63

(631-770)

Trofimik, S., Tretyakevich, S., Drozdovitch, V., Shagalova, E., Zhukova, O., Germenchuk, M., Berlovich, S. (2006). Measurement of I-129 and Cs-137 in soils from Belarus and construction of I-131 deposition from the Chernobyl accident.

Troposphere: Comparison of Model Calculations with Recent Field Data. *Journal of* 

radioactive waste streams. *Nuclear Instruments and Methods in Physics Research A,*

measurement of iodine-129/iodine-127 ratio by accelerator mass spectrometry. *Journal of Nuclear Science and Technology,* Vol. 43, No. 44, pp. (1431-1435), ISSN 0022-

seawater samples collected from the Japan Sea area using accelerator mass spectrometry: Contribution of nuclear fuel reprocessing plants. *Quaternary* 

(2003a). Origin and history of waters associated with coalbed methane: 129I, 36Cl, and stable isotope results from the Fruitland Formation, CO and NM. *Geochimica et* 

Central American geothermal settings: Noble gas and I-129 evidence for crustal and magmatic volatile components. *Geochemistry Geophysics Geosystems,* Vol. 4, Article

iodine cycling in surface reservoirs. *Nuclear Instruments and Methods in Physics* 

Suter, M., López-Gutiérrez, J.M., Städe, W. (2000a). Iodine-129: Sample preparation, quality control and analyses of pre-nuclear materials and of natural waters from Lower Saxony, Germany. *Nuclear Instruments and Methods in Physics Research B,* Vol.

Analysis of iodine-129 in environmental materials: Quality assurance and applications. *Journal of Radioanalyticaland and Nuclear Chemistry,* Vol. 244, No. 1, pp.

Dose Assessment Technologies, United Nations Scientific Committee on the Effects

iodotyrosines and iodothyronines in proteins using high-performance liquid


Reithmeier, H., Lazarev V., Kubo, F., Rühm, W., Nolte, E. (2005). 129I in precipitation using a

Reithmeier, H., Lazarev, V., Rühm, W., Schwikowski, M., Gäggeler, H., Nolte, E. (2006).

Salbu, B. (2007). Speciation of radionuclides – analytical challenges within environmental

Sanchez, L.F., Szpunar, J. (1999). Speciation analysis for iodine in milk by size-exclusion

Santos, F.J., Lopez-Gutierrez, J.M., Garcia-Leon, M., Suter, M., Synal H.A. (2005).

Schmitz, K., Aumann, D.C. (1995). A study on the association of two iodine isotopes, of

Santschi, P.H., Schwer, K.A. (2004). 129I/127I as a new environmental tracer or

Schnabel, C., Olive, V. Atarashi-Andoh, M., Dougans, A., Ellam, R.M., Freeman, S., Maden,

Schwehr, K.A., Santschi, P.H., Elmore, D. (2005). The dissolved organic iodine species of the

Shah, M., Wuilloud, R.G., Kannamkumaratha, S.S., Caruso, J.A. (2005). Iodine speciation

*Environmental Radioactivity,* Vol. 84, No. 1, pp. (103-109), ISSN 0265-931X Santos, F.J., Lopez-Gutierrez, J.M., Chamizo, E., Garcia-Leon, M., Synal H.A. (2006).

*Physics Research B,* Vol. 239, No. 3, pp. (273-280), ISSN 0168-583X

936X

pp. (47-53), ISSN 0265-931X

No. 1-2, pp. (772-775), ISSN 0168-583X

Vol. 321, No. 1-3, pp. (257-271), ISSN 0048-9697

482, No. 1, pp. (59-71), ISSN 0003-2670

Vol. 20, No. 3, pp. (176-182), ISSN 0267-9477

*Methods,* Vol. 3, pp. (326-337)

1702), ISSN 0267-9477

pp. (229-236)

new TOF system for AMS measurements. *Nuclear Instruments and Methods in* 

Estimate of European 129I Releases Supported by 129I Analysis in an Alpine Ice Core. *Environmental Science and Technology,* Vol. 40, No. 19, pp. (5891-5896), ISSN 0013-

impact and risk assessments. *Journal of Environmental Radioactivity,* Vol. 96, No. 1-3,

chromatography with inductively coupled plasma mass spectrometric detection (SEC-ICP MS). *Journal of Analytical Atomic Spectrometry,* Vol. 14, No. 11, pp. (1679-

Determination of 129I/127I in aerosol samples in Seville (Spain). *Journal of* 

Advances on the determination of atmospheric 129I by accelerator mass spectrometry (AMS). *Nuclear Instruments and Methods in Physics Research B,* Vol. 249,

natural 127I and of the fission product 129I, with soil components using a sequential extraction procedure. *Journal of Radioanalytical and Nuclear Chemistry,* Vol. 198, No. 1

geochronometer for biogeochemical or hydrodynamic processes in the hydrosphere and geosphere: the central role of organo-iodine. *Science of the Total Environment,*

C., Stocker, M., Synal, H.A., Wacker, L., Xu, S. (2007). 129I/127I ratios in Scottish coastal surface sea water: Geographical and temporal responses to changing emissions. *Applied Geochemistry,* Vol. 22, No. 3, pp. (619-627), ISSN 0883-2927 Schwehr, K.A., Santschi, P.H. (2003). Sensitive determination of iodine species, including

organo-iodine, for freshwater and seawater samples using high performance liquid chromatography and spectrophotometric detection. *Analytica Chimica Acta,* Vol.

isotopic ratio of 129I/127I: A novel tool for tracing terrestrial organic carbon in the estuarine surface waters of Galveston Bay, Texas. *Limnology and Oceanography:* 

studies in commercially available seaweed by coupling different chromatographic techniques with UV and ICP-MS detection. *Journal of Analytical Atomic Spectrometry,*


**19** 

*Chile* 

**Hydrodynamic Characterization of Industrial** 

In order to study the hydrodynamic behaviour of large flotation machines, the radioactive tracer technique has been used to measure a number of internal characteristics such as: • Residence time distribution (RTD) of liquid, solid and gas, in industrial cells and

Industrial flotation cells need to accomplish several functions such as: air bubble dispersion, solid suspension as well as to provide the best conditions for bubble-particle collision, aggregate formation and froth transport. For this reason, cells are typically provided with mechanical agitation systems which generate well mixed conditions for the pulp and air bubbles. In an industrial mechanical cell, however, the mixing condition prevents that particles have the same opportunity to be collected because a significant fraction of them actually spent a very short time in the cell (in a well-mixed condition almost 40% of particles stay in the cell for less than a half of the mean residence time). Because of the large short circuit in single continuous cells, the industrial flotation operation considers the arrangement of cells in banks. Thus, banks of 5-10 cells in series are commonly used in plant practice. The largest flotation cells presently used in industrial flotation operation are 130, 160, 250 and 300 m3. Figure 1 show the main characteristics of a self-aerated mechanical flotation cell, where the feed pulp circulates upwards through a draft tube by the rotor. Also, the air is self-aspirated from the upper

**1. Introduction** 

**1.1 Objective and organization of chapter** 

• Direct measurement of gangue entrainment. • Industrial flotation cell scanning with gamma ray. • Pulp flowrate distribution in parallel flotation banks.

**1.2 Relevance to industrial flotation machines**

• Flotation rate distribution.

part of the cell by the rotor.

columns. Actual mean residence time evaluation.

• Mixing regime in single cells, banks of cells and pneumatic columns. • Froth mean residence time of liquid, floatable and non-floatable solids. • Mixing time and internal pulp circulation in large industrial self-aerated cells.

• Gas holdup and gas residence time distribution in flotation machines.

**Flotation Machines Using Radioisotopes** 

*1Department of Chemical Engineering, Santa Maria University, 2Nuclear Applications Dept., Chilean Commission of Nuclear Energy,* 

Juan Yianatos1 and Francisco Díaz2

chromatography by photodiode-array ultraviolet-visible detection. *Journal of Chromatography B,* Vol. 688, No. 1, pp. (143-149), ISSN 0378-4347

