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Lynas: Radioactive Waste Dumping from Rare Earth Refining. Chan Chee Khoon People’s Health Forum, Malaysia ckchan50@yahoo.com July 7, 2012. Rare Earth Elements (Lanthanides).
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Lynas: Radioactive Waste Dumping from Rare Earth Refining Chan Chee Khoon People’s Health Forum, Malaysia ckchan50@yahoo.com July 7, 2012
Rare Earth Elements (Lanthanides) • Valuable ingredients in powerful miniaturized magnets, in metal alloys, as catalysts in oil and gas industries, optical enhancers in high performance video display screens (Prius hybrid car motors & batteries, smart-phones, wind turbines, precision bombs, etc) • China currently produces ~ 95% rare earth minerals • Export controls, skyrocketing prices of rare earths (US$ 5/kg, 2003 US$ 109/kg, Feb 2011) • Lynas plans on supplying 20-30% global market when fully operational (largest RE refinery in the world)
Lynas Rare Earth Minerals Refinery • REOs (40% concentrates) imported from W Australia • Gebeng refinery - digestion with concentrated acids, extraction and purification • also produces 20,000 tonnes powdery solid wastes annually ~1600 ppm 232Thorium and lesser amounts of 238Uranium and their radioactive progenies • long term plan for solid waste disposal? • onsite RSF (10 years capacity) • recycle by re-dilution in bulk manufacture of cement, road base, fertilizer & gypsum products(?)
Ionizing Radiation • Alpha (α) radiation (helium nucleus, 8000x mass of electron) • Beta (β) radiation (electron, or positron with accompanying neutrino) • Gamma (γ) radiation (short wavelength energetic ray) • Radiation dosimetry (inverse square law); α-dosimetry • Bio-kinetics of internal emitters (absorption, mobility, retention, excretion, localisation [down to the sub-cellular and molecular level])
Unexplained Excess of Childhood Leukemias • ‘safe thresholds’ of 1 mSv/yr (public), 20 mSv/yr (occupational) based on ICRP’s quantitative risk models – calibrated against external irradiation (Hiroshima/Nagasaki atomic bomb blasts) • Sellafield nuclear reprocessing plant (UK, 1983) • Chernobyl (Ukraine, 1986) • KiKK study (Germany, children <5yr). Residence <5km from nuclear power plant, doubling of childhood leukemia risk Int J Cancer, February 2008 • Geocap study (France, children <15 yr). Residence <5km vs. >20km from nuclear power plant, doubling of childhood leukemia risk Int J Cancer, February 2012 • above excesses @ exposures 100-1000x below 1 mSv/yr
Competing Hypotheses • could the excess leukaemia be due to inhaled or ingested radioactive particulates not satisfactorily accounted for in ICRP’s risk models? A UK expert panel (2004, ) could not arrive at a consensus regarding the health risks of low level exposure to these internal emitters. Opinions among the UK panel members ranged from negligible adverse effects to an underestimation of risk by at least a 100 fold – clearly no consensus among the experts. • could the excess leukaemia be due to electromagnetic fields associated with high voltage power cables linked to the nuclear power stations? • or to population mixing and vulnerability to infectious agents suspected of causing leukaemia? (Kinlen hypothesis) • or to paternal irradiation of reproductive gametes? (Gardner) • or to teratogenic effects on the developing foetus/embryo? (Fairlie) No one can be sure.
ARE’s legacy – a neglected, continuing problem • indiscriminate clandestine dumping of thorium-cake wastes in 1980s - Lahat, Menglembu, Pengkalan, Jelapang, Buntong, Simpang Pulai, among other locations • thorium cake wastes from ARE’s operations contained up to 360,000 ppm 232Thorium (Akademi Sains Malaysia, 2011)1 • unknown number of dump sites at unknown locations? • excess childhood leukemias in greater Ipoh? • lung cancers among ARE employee cohorts? • Kledang dumpsite – gas seepage containing 222Radon? 1 Rare Earth Industries: Moving Malaysia’s Green Economy Forward, p.30, table 2.9, Akademi Sains Malaysia, August 2011. ARE’s thorium cake wastes also contain 7000ppm 238Uranium which decays to 222Radon (half-life 3.8 days, alpha-emitter; lung cancer risk factor)