EdF try to excuse their radioactive mud by comparing the gamma-radiation to that from eating 20 bananas.
They also use airline pilots and radon-homes as comparators in their
statement to the Senedd . They doubtless use these hoary old arguments because they have not met the real international standard for dumping at sea (see
FoE Brief).
What's wrong with the banana argument? Bananas contain potassium, with the tiny fraction of radio-potassium (0.01%) as throughout the environment. The human body needs potassium - contains far more than from 20 bananas - but quickly excretes any more than it needs. Eating bananas adds nothing to the body burden. Radio-carbon, as in all foods, contributes more to damaging the body's cells in emitting beta-radiation. Radiopotassium has fewer emissions but of gamma radiation which very largely passes out of the body, like X-rays.
Airline pilots are at risk from cosmic radiation; they choose to take that risk and are paid highly for it. Homes in radon areas are fitted with measures to disperse this radioactive gas filtering through the rocks, which otherwise filters into homes and causes comparable risks to tobacco smoking. For EdF to impose the risk on everyone who uses local beaches, eats local food, or simply breathes in microparticles from sea-spray is quite different. Individual risks may be small, but international regulation sets a limit on the "collective" risk to the population.
A second point is the failure to assess the total harm to humans. The main damage is not from the gamma rays that pass through us, but from inhaled and ingested nuclides which emit alpha or beta radiation. The nuclear industry assesses gamma-equivalent dose, as in the ICRP standard, but this has long been disputed. The Government's Cerrie committee on internal radioactive emitters,
reporting in 2004, established significant science behind internal emitters. Its minority
report led to alternative ECHR standards, but nuclear interests have refused to take these up in the IAEA standards - these still cover simple gamma-radiation alone. Alpha and beta emitters must however be taken into account in specific assessment of the harm from Hinkley's mud, as the radionuclides are taken up in marine life and by humans around the Severn Estuary. The radium measured in the deep mud samples is an alpha emitter, causing damage at the cell-level - the
radium-girls painting luminous dials are the famous example. The Wales-based
Low Level Radiation Campaign has longstanding expertise in this area, proceeding from the Cerrie findings.
EdF's claim
"an infinitesimally small level of exposure to radiation, far below the threshold requiring a more detailed assessment or even close to approaching a radiation dose that could impact human health or the environment"
is obviously false, even on IAEA/ICRP standards. The gamma-exposure of dredge workers was calculated at 5.8 uSv/yr, which is only marginally below the IAEA limit of 10 uSv/yr. These numbers alone are close enough to require that the deep mud is sampled to international standards and the 5.8 figure revised upwards. Then compliance with international standards requires the "detailed assessment" they want to avoid by the banana argument.
