Atomic Spin

On March 30, The Daily Express ran with this front page this front page article:

The headline’s technically true, but the scale of the radioactive fallout compared to the media fallout is a bit out of sync. Slightly elevated levels of the radioactive isotope iodine-131 (I-131) have been seen in Glasgow and Oxfordshire, but the key word here is slightly.

The levels of I-131 detected in Oxfordshire rose by 0.0003 becquerel per cubic metre (Bq/m³), while in Glasgow it rose by just 0.00001 Bq/m³. A becquerel (Bq) is the unit of radioactivity; 1 Bq means you have one radioactive atom decaying and releasing radiation per second. These decays are what produce the distinctive clicks of a Geiger counter; each “click” represents a flash of radiation from the decay of one atom. As you may have seen in school, even when held away from radioactive sources a Geiger counter will probably give you a click or two per second – we’re surrounded natural radiation from the air, the ground, space and even from our own bodies. Around you right now, radon gas is releasing, on average, 20 Bq/m³ of radiation while inside your body, radioactive potassium-40 is decaying at over 4,000 Bq, and carbon-14 is producing radiation at a similar rate. Compared this background radiation, the change due to fallout is minimal: 0.0003 Bq is equivalent to one atom of radioactive iodine decaying per hour, and 0.00001 Bq is one extra decay per day. (For some perspective, after Chernobyl I-131 levels in the air at Harwell reached a maximum of 4 Bq/m³, ten thousand times the levels seen in Oxfordshire.)

Working out how much harm radiation causes isn’t always easy – a few bequerels from radon gas are more harmful than the thousands of bequerels released by potassium in your body, since radon releases harmful alpha radiation instead of the comparatively safe gamma radiation, and radon spends most of its time lurking in your delicate lungs – so to work out the risk you need to work out the equivalent dose, a measure of how much damage the radiation does to the body usually measured in sieverts. Being exposed to 0.0003 Bq/m³ extra I-131 is equivalent to an increased dose of 0.01 microsieverts (μSv) per year. You would absorb almost as much radiation just by sleeping next to someone for one night. For comparison, the smallest dose that we know to be harmful is around 100,000 microsieverts per year; millions of times more than anyone in the UK could receive from the fallout.

The Express quotes John Large, one of the critics of the nuclear industry, as saying:

The International Commission on Radiological Protection – which is made up of government agencies – is quite clear. It says any increase in accumulated radiation dose exposure is accompanied by a proportionate increase in risk. That is the natural law.

For Sepa [Scottish Environmental Protection Agency] to make profound statements about it is ‘not of concern’ to the public is not right. Of course the risk’s tiny but it’s up to the public to decide.

If you want the public to make an informed decision about nuclear power, it has to actually be informed. Screaming about “TSUNAMI NUCLEAR FALLOUT” without providing any context is not helpful, it’s just scaremongering, plain and simple.

Since the harmful dose for radiation is 5 million times higher than the levels found in Oxfordshire, I wonder what John Large would like Sepa to have said. Saying that these radiation levels are not of concern is not leading the public on, it’s simply a cold, hard medical fact. If Large does think these radiation levels are of concern, then may I suggest that his next statement focuses on the extreme dangers of radioactive bedmates.