From The Guardian UK: http://www.guardian.co.uk/environment/2011/apr/11/nuclear-apologists-radiation
George Monbiot and others at best misinform and at worst distort evidence of the dangers of atomic energy
guardian.co.uk, Monday 11 April 2011
Soon after the Fukushima accident last month, I stated publicly that a nuclear event of this size and catastrophic potential could present a medical problem of very large dimensions. Events have proven this observation to be true despite the nuclear industry’s campaign about the “minimal” health effects of so-called low-level radiation. That billions of its dollars are at stake if the Fukushima event causes the “nuclear renaissance” to slow down appears to be evident from the industry’s attacks on its critics, even in the face of an unresolved and escalating disaster at the reactor complex at Fukushima.
Proponents of nuclear power – including George Monbiot, who has had a mysterious road-to-Damascus conversion to its supposedly benign effects – accuse me and others who call attention to the potential serious medical consequences of the accident of “cherry-picking” data and overstating the health effects of radiation from the radioactive fuel in the destroyed reactors and their cooling pools. Yet by reassuring the public that things aren’t too bad, Monbiot and others at best misinform, and at worst misrepresent or distort, the scientific evidence of the harmful effects of radiation exposure – and they play a predictable shoot-the-messenger game in the process.
1) Mr Monbiot, who is a journalist not a scientist, appears unaware of the difference between external and internal radiation
Let me educate him.
The former is what populations were exposed to when the atomic bombs were detonated over Hiroshima and Nagasaki in 1945; their profound and on-going medical effects are well documented. 
Internal radiation, on the other hand, emanates from radioactive elements which enter the body by inhalation, ingestion, or skin absorption. Hazardous radionuclides such as iodine-131, caesium 137, and other isotopes currently being released in the sea and air around Fukushima bio-concentrate at each step of various food chains (for example into algae, crustaceans, small fish, bigger fish, then humans; or soil, grass, cow’s meat and milk, then humans).  After they enter the body, these elements – called internal emitters – migrate to specific organs such as the thyroid, liver, bone, and brain, where they continuously irradiate small volumes of cells with high doses of alpha, beta and/or gamma radiation, and over many years, can induce uncontrolled cell replication – that is, cancer. Further, many of the nuclides remain radioactive in the environment for generations, and ultimately will cause increased incidences of cancer and genetic diseases over time.
The grave effects of internal emitters are of the most profound concern at Fukushima. It is inaccurate and misleading to use the term “acceptable levels of external radiation” in assessing internal radiation exposures. To do so, as Monbiot has done, is to propagate inaccuracies and to mislead the public worldwide (not to mention other journalists) who are seeking the truth about radiation’s hazards.
Continue reading at: http://www.guardian.co.uk/environment/2011/apr/11/nuclear-apologists-radiation