LETTER | Some rare earths mining advocates evidently are unaware of the lack of consensus among radiobiologists and radiation safety specialists regarding the health risks of chronic, low-level exposure to ionising radiation from internal emitters.
The “safe thresholds” of 1 mSv/yr (public) and 20 mSv/yr (occupational) that they repeatedly invoke are pragmatic recommendations on dose limits from the International Commission on Radiological Protection (ICRP) which relies on quantitative risk models largely calibrated against external sources of instantaneous irradiation of large human populations, most importantly, the long-term follow-up studies of survivors of the Hiroshima and Nagasaki atomic bomb blasts, as well as patients subjected to medical X-rays.
Whether these risk models are adequate for assessing the health risks of chronic exposure to low-level ionising radiation from ingested or inhaled radioactive particulates (notwithstanding periodic updates and refinements), remain contentious especially in the wake of excess childhood leukaemia near nuclear power plants that could not be explained by radiation exposures which were two to three orders of magnitude below the “safe thresholds”.
Most notably, two large epidemiological studies in Germany (KiKK, 2008) and in France (Geocap, 2012) have reported statistically robust findings of a doubling of leukaemia risk among children living within a 5 km radius of a nuclear power plant, where radiation exposures were much below 1 mSv/yr.
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 (Cerrie, 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 up to 10-fold (see for instance a four-page summary by Cerrie panel member Dr Philip Day on why health risks of internal emitters need to be fundamentally re-assessed.
Could the excess leukaemia be due to electromagnetic fields associated with high voltage power cables be linked to the nuclear power stations? Or to population mixing and vulnerability to infectious agents suspected of causing leukaemia? (Kinlen hypothesis). No one can be sure.
In other words, nobody really knows at this point how safe (or hazardous) a rare earths refinery may be given that much of the radioactive solid wastes are in powder form, i.e. respirable when dry as suspended particulates or ingestable from contaminated surfaces.
When experts in radiation safety disagree among themselves, the Precautionary Principle becomes even more important in public health practice (let’s recall that obstetric X-rays were considered safe by the medical and scientific community until the 1950s, when Professor Alice Stewart (Oxford) raised the alarm with her findings of increased risk of childhood leukaemia.
These findings were initially also dismissed as a fringe minority opinion - by Richard Doll, no less, the doyen of cancer epidemiologists and regius professor of medicine at Oxford - but Stewart’s persistence eventually saw them incorporated into mainstream medical practice).
Rare earths mining advocates are either unaware of the unresolved debates over internal emitters or are being cavalier with the Precautionary Principle.
In contrast to the state of California for instance, where Molycorp had to comply with a zero liquid wastes discharge requirement, or in Germany, where the popular will obliged Angela Merkel to phase out nuclear power plants even as scientists and researchers continue to lock horns over the unexplained excess of childhood leukaemia in the vicinity of nuclear power plants and nuclear-reprocessing facilities.
Most pertinent to us perhaps, is the case of an Australian company, Arafura Resources Limited and its proposed rare earth operations in Australia, as an illustrative example of how the Precautionary Principle is operationalised there. The Department of Natural Resources, Environment, the Arts and Sport of the Northern Territory Government had the following conditionality for the issuance of an operating license “Item 1.3.5 Receipt and storage of waste from (off-site) ore processing”
Tailings produced from the off-site processing of ore (i.e. processing waste) are proposed to be transported back to the mine-site for long-term storage. The processing waste will contain radioactive material (e.g. thorium)”. In plain language, the radioactive solid wastes produced by Arafura’s mining, ore concentration, and refining processes were to be returned to the originating mine-site at Nolans Bore (near Alice Springs, NT) for secure burial.
In accordance with principles of environmental justice, it was considered unfair to burden the residents of Whyalla, South Australia (location of the proposed rare earths refinery) with anxieties over their community’s health.
Applying the same standard of precaution locally would require operators to return their radioactive solid wastes to its originating mine-site wherever that may be.
We recall that the Asian Rare Earth (ARE) refinery at Bukit Merah (Ipoh) had very opaque long-term waste management plans if any. Ad hoc arrangements, including the aborted Papan dump-site, eventually led to a situation of indiscriminate open dumping of radioactive thorium-cake wastes at Lahat, Menglembu, Pengkalan, Jelapang, Buntong, Simpang Pulai among other locations.
It would be sad if local communities end up as lab rats in an experiment again.
The writer is attached to the Citizens Health Initiative.
The views expressed here are those of the author/contributor and do not necessarily represent the views of Malaysiakini.