Tritium’s health hazards: why we should be concerned Dr Ian Fairlie Consultant on Radiation in the Environment London United Kingdom Tritium releases from reactor types TBq per GW(e) yr Heavy Water Reactor Pressurised Water Reactor Boiling Water Reactor 670 20 2 data source: UNSCEAR (2000) Tritium Release Limits TBq/year (combined liquid and gaseous) COUNTRY Nuclear Power Station TBq /year Canada Darlington Belgium Doel 100 Germany All sites 70 846,000 Netherlands Borssele 30 UK 8 Sizewell Key Problem official dose per Bq for tritium is very low therefore the estimated tritium “doses” are usually tiny but the huge tritium releases mean if tritium’s dose estimates are wrong, the health consequences could be serious Tritium doses from inhalation (EU RODOS Model) in mSv 8th Meeting of the IAEA (EMRAS) Tritium & C-14 Working Group May 30 - June 1, 2007 - Bucharest, Romania (http://www.nipne.ro/emras/) Tritium doses from ingestion (EU RODOS Model) in mSv 8th Meeting of the IAEA (EMRAS) Tritium & C-14 Working Group May 30 - June 1, 2007 - Bucharest, Romania (http://www.nipne.ro/emras/) Estimated tritium levels in cow’s milk (EU RODOS Model) HTO Bq/kg 8th Meeting of the IAEA (EMRAS) Tritium & C-14 Working Group May 30 - June 1, 2007 - Bucharest, Romania (http://www.nipne.ro/emras/) Estimated tritium levels in cow’s milk (EU RODOS Model) OBT Bq/kg 8th Meeting of the IAEA (EMRAS) Tritium & C-14 Working Group May 30 - June 1, 2007 - Bucharest, Romania (http://www.nipne.ro/emras/) Tritium concentrations in air near Canadian reactors Bq/m3 from Osborne RV (2002) Tritium in the Canadian Environment: Levels and Health Effects. Report RSP 0153-1. Prepared for the CNSC. Tritium concentrations in food near Canadian reactors - Bq/l from Osborne RV (2002) Tritium in the Canadian Environment: Levels and Health Effects. Report RSP 0153-1. Prepared for the CNSC. Estimated annual tritium intakes near a Canadian nuclear power station after Osborne, 2002; annual intake values from Health Canada (1994) Tritium source Intake per Tritium Bq/year annum concentration Water in food 425 litres ~2,000 Bq/L 850,000 Air Inhalation 8,400 m3 10 Bq/m3 84,000 Water in drinks 550 litres 100 Bq/L 55,000 10 Bq/m3 33,000 ~700 Bq/kg ~53,000 Skin absorption OBT in food TOTAL 60% of inhalation 75 kg ~1,000,000 Controversy over Tritium’s “Doses” tritium’s dose coefficient is the smallest (by far) of all radionuclides often described as a “weak” emitter, but 2-3 times more hazardous than most gamma/beta emitters major misconceptions present 3 main problems Reports discussing the Controversy Over Tritium Doses 1. 2. 3. 4. 5. AGIR HPA Report (2007) Review of Risks from Tritium Melintescu A, Galeriu D and Takeda H (2007) Reassessment Of Tritium Dose Coefficients For The General Public. Radiat Protect Dosim June 2007, pp. 1–5 Fairlie I (2007) RBE and wR values of Auger emitters and low-range beta emitters with particular reference to tritium. Journal of Radiol Prot. Vol 27 pp 157-168 US EPA draft White Paper. Modifying EPA Radiation Risk Models Based on BEIR VII. August 1 2006 Makhijani A, Smith B, and Thorne MC (2006) Science for the Vulnerable: Setting Radiation and Multiple Exposure Environmental Health Standards to Protect Those Most at Risk. See chapter 7 on tritium. http://www.ieer.org/campaign/report.pdf What’s Wrong? 1. Wrong radiation weighting factor (wR) 2. Wrong metabolic/dosimetric models 3. Refusal to acknowledge its hazards 1. Radiation “weighting” (wR) is Wrong An important issue UK (AGIR) says wR x 2 US EPA says wR x 2.5 but ICRP says it won’t change (because of French obsession with fusion research ITER at Cadarache) Observed RBE values from Fairlie I (2007) RBE and wR values of Auger emitters and low-range beta emitters with particular reference to tritium. Journal of Radiological Protection. Vol 27 pp 157-168 Distribution of RBEs for HTO/gamma 4 3.5 RBE 3 2.5 2 1.5 1 0.5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Experiment 2. Tritium Models are Poor No recognition of tritium levels building up to high levels from chronic exposures No consideration of heterogenous distribution of tritium, especially OBT OBT badly modelled: experimental animal and human data ignored 3. Unusual Tritium Properties unrecognised Extreme mobility in environment (as H2O) Rapid uptake in biota, ie humans 60% of atoms in humans are H atoms High atomic exchangeability Ability to bind with organic materials 5% in metabolic reactions each day Short-range beta particle, so damage depends on location in cell, eg near DNA? Overall Result: Tritium’s dose coefficient should be increased x 20 1. 2. 3. Weighting Factor = x 2.5 Correct Models =x4 Hazardous Nature = x 2 Therefore need to increase tritium doses by 2.5 x 4 x 2 = 20 Precautionary Principle Ie - err on the side of caution Do not use scientific uncertainty as excuse for inactivity where there is some evidence of harm – act to reduce or avoid it or warn about it Main Conclusions high tritium concentrations in air moisture, food, water near NPPs therefore high tritium exposures to nearby residents likely cancers, leukemias (but hard to pick up) Main Recommendations 1. 2. 3. 4. 5. Use Precautionary Principle Set up permanent health committees on tritium with NGO reps Further epidemiology studies Advise local people Tighten tritium limits Health Recommendations protect the vulnerable and most exposed pregnant women, nursing mothers, and children (under 4) should not live within 10 km people within 5 km should not consume food from their gardens, beehives, orchards, and wild foods growing nearby Globe and Mail: June 12 2007 Useful References Canadian Nuclear Safety Commission (2001) Tritium in the Canadian Environment: Levels and Health Effects. Report RSP-0153-1. Prepared for the Canadian Nuclear Safety Commission under CNSC contract no. 87055-01-0184 by Ranasara Consultants and Richard Osborne. CERRIE (2004) Report of the UK Government’s Committee Examining the Radiation Risks of Internal Emitters. www.cerrie.org Energy Washington Week (2007) “EPA Tritium Risk Plan May Force Tighter Nuclear Plant Controls”, Vol. 4, No. 25, 20 June 2007. Fairlie I (2007) RBE and wR values of Auger emitters and low-range beta emitters with particular reference to tritium. Journal of Radiological Protection. Vol 27 pp 157-168. (2007) http://www.iop.org/EJ/abstract/0952-4746/27/2/003/ Greenpeace Canada. (2007) Tritium Hazard Report: Pollution and Radiation Risk from Canadian Nuclear Facilities. http://www.greenpeace.org/raw/content/canada/en/documents-and-links/publications/tritium-hazard-report-pollu.pdf Health Canada (1994) Human Health Risk Assessment for Priority Substances. Ottawa, Canada: Ministry of Supply and Services Canada. http://www.iop.org/EJ/abstract/0952-4746/27/2/003/ Hey E (1995) The Precautionary Principle. Where Does It Come From And Where Might It Lead In The Case Of Radioactive Releases To The Environment. In Proceedings of an International Atomic Energy Agency Symposium on The Environmental Impact of Radioactive Releases. Vienna, May 1995. IAEA-SM-339/195. Kirchner G (1990) A New Hazard Index for the Determination of Risk Potentials of Radioactive Waste. J of Environmental Radioactivity, 11, pp 71-95. Makhijani A, Smith B, and Thorne MC (2006) Science for the Vulnerable: Setting Radiation and Multiple Exposure Environmental Health Standards to Protect Those Most at Risk. See chapter 7 on tritium. http://www.ieer.org/campaign/report.pdf OECD/NEA (1980) Radiological Significance and Management of Tritium, Carbon-14, Krypton-85, and Iodine-129 Arising from the Nuclear Fuel Cycle Nuclear Energy Agency of OECD, Paris. Ontario Drinking Water Advisory Council (2009) Report and Advice on the Ontario Drinking Water Quality Standard for Tritium. http://www.odwac.gov.on.ca/reports/minister_reports.htm Ontario Government’s Select Committee on Ontario Hydro Affairs: Hearings on The Safety of Ontario's Nuclear Reactors. Tuesday, July 10, 1979. http://www.ccnr.org/tritium_2.html#scoha Osborne RV (1966) Absorption of tritiated water vapour by people. Health Phys 12:1527-1537 Osborne RV (2002) Tritium in the Canadian Environment: Levels and Health Effects. Report RSP-0153-1. Prepared for the Canadian Nuclear Safety Commission. Paunescu N, Cotarlea M, Galeriu D, Margineanu R and Mocanu N (1999) Evaluation of environmental tritium levels in pre-operational period of Cernavoda CANDU Nuclear Power Plant. Journal of Radioanalytical and Nuclear Chemistry Volume 239, Number 3. March 1999. pages 465-470. Porter Commission (1980) The Report of the Royal Commission on Electric Power Planning. Volume 6. Environmental and Health Implications of Electric Energy in Ontario. p 85. Ontario Government, Toronto, Ontario, Canada. Societatea Nationala “Nuclearelectrica” S.A. CNA Cernavoda. (2005) Raport di Mediu. Song MJ, Son SH and Jang CH (1995) Tritium Inventory Prediction in a Candu Plant. Water Management Vol 15 No 8 pp 593-598.. UNSCEAR (2000) Sources and Effects of Ionizing Radiation. United Nations Scientific Committee on the Effects of Atomic Radiation. New York NY USA. Varlam C et al (2005) The use of tritiated wastewater from NPP Cernavoda to estimate maximum soluble pollutants on the Danube - Black Sea channel. Fusion Science and Technology, vol. 48, no 1., pp. 716-719. Workman WJ, Trivedi A and Cornett RJ (1998) Tritium Concentrations inside the Homes of Occupationally Exposed Workers: Dosimetric Implications. Health Physics Vol 75 No 1, pp 56-59.