Monday, July 1, 2013

Nuclear deaths- not many, honest!

Just after the Fukushima disaster, the BBC’s  ‘Bang Goes the Theory’ popular science programme had a look at nuclear safety and health impacts. Based on presentations from Prof Gerry Thomas from Imperial College, it was suggested that only 122 people were known to have died as a result of the Chernobyl disaster and that none would die due to Fukushima. Amongst others, the Nuclear Consult group of over 50 academics submitted a complaint, alleging that this was a biased, partial account.  The BBC subsequently admitted, on its complaints website, that ‘the figure 122 was presented as definitive whereas certainty is in fact lacking’, But it added, ‘the programme was misleading in that respect, though not to a degree which might have amounted to bias in relation to the arguments about nuclear power’

That is a matter of opinion. A UN backed report in 2006 estimated that among the 600 000 persons receiving significant exposures (liquidators, evacuees, and residents of the most ‘contaminated’ areas), about 4,000 extra fatal cancers might occur and that among the 5 million persons residing in less contaminated areas with lower doses, an additional 5,000 cancer deaths might occur. These estimates were speculative, and later UN studies talked of stress playing a role in observed illnesses. However , it has been accepted that that there had been over 4,000 cases of thyroid cancer in children and adolescents who were exposed at the time of the accident, although in nearly all cases that was treatable.  The debate continued. Independent studies claimed that the total death toll could be in the range of 30,0000-60,000 . See  and

Nuclear Consult persevered with their complaint via the BBC Trust and recently received a further response. This reiterated the view that with regard to Chernobyl, the failure to mention known non-fatal health effects and the decision not to put the “observable” deaths into a wider context meant the audience would not be able to reach a reliable conclusion. This was not consistent with the stated aim of the programme to get to “the truth about the effects of radiation”, and would not have met audience expectations.

But it added ‘whilst the finding of inaccuracy in relation to the programme’s representation of the scale of health impacts from the Chernobyl fallout acknowledged the health impact was greater than the programme reflected, the programme’s broader
contention that in relative terms the impact was not as great as some people have
come to believe appears to have been well-founded.’

 It also found that ‘with regard to the prediction of zero deaths as a result of the Fukushima accident, Prof. Thomas was offering an informed judgement and not stating an established fact, and that she was qualified to do so as an acknowledged expert in the field of radiation and human health. The Committee noted that her conclusion was broadly in line with other informed opinion’. See ‘Sept’ 2012 on the BBC Trusts web site:
Does that includes the very cautious Stanford University study which concluded there would be between 15 and 1100 radiation related cancer deaths due to Fukushima, with their best estimate being 130 deaths, plus 24 to 1800 non-lethal cancers, with 180 being their best estimate? It noted that 600 people had died as a result of the evacuation. Given uncertainties about the location/exposure of evacuees and also the unreliability of the radiation impact model used for low doses, it said upper bound mortalities and morbidities could be increased to 1300 and 2500, respectively. 
Some more recent estimates put the possible death toll higher: see Nuclear Monitor 758
However,  it will take time before any impacts show- it can take decades for cancers to present. This hasn’t stopped the UN Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) from issuing preliminary findings last December, in which it  said that that so far no radiation health effects had been observed in Japan among the public, workers or children in the area of the Fukushima Daiichi nuclear power plant: it claimed that the doses of radiation received were low and no discernible health effect could be expected. It admitted that there were impact 
uncertainties at low doses, but did not recommend multiplying low doses by large numbers of individuals to estimate numbers of radiation-induced health effects. Six workers received total doses of over 250 mSv during their time tackling the emergency, while 170 received doses over 100 mSv, but none of these have shown ill effects so far. Amongst the general public, it says the largest dose thought to have been received by a Japanese child is 35 mSv.  Background level is around 2mSv, but the critics of the ‘low does is no problem’ view say that’s for external exposure: internally absorbed radioactive material is likely to have a much larger, longer term, impact. Time will tell.
In a subsequent report, the World Health Organisation repeated the ‘low risk’ claim. It calculated that in the worst hit areas there could be an increase in solid cancer risk of 4% for females exposed as infants. In Japan, 29.04% of females develop solid cancer by the age of 89, so an increase in that risk of 4% would raise it to 30.20% among females in the most exposed population, with breast cancer risk rising 6% in females, raising the risk for the exposed group from 5.53% to 5.86% by the age of 89., while the risk of leukemia in males might rise  by around 7% in males exposed as infants, raising the risk for the exposed group from 0.6% to 0.64% by age 89. The risk of developing (treatable) thyroid  cancer was estimated to have risen by 70% in females exposed as infants but with "little risk apparent after the age of 20." The overall thyroid risk estimate was raised from 0.75% to 1.27% by age 89. Given these figures, it concluded that  no observable increases in cancer rates above baseline rates are anticipated’.

We will have to wait a few decades to find out if they are right.. UNSCEAR is to do further studies, including, in 2014, a review of the epidemiology of low-dose radiation risks and WHO did recommend long term monitoring. Like UNSCEAR, WHO's used  the linear ‘no-low threshold’ method of gauging health effects, which on one hand, the industry sees as overestimating impacts from low doses and on the other some scientist feel underestimates the impact, for example of ingestion of  radioactive material, even at radiation levels below (external) background. So there are unresolved scientific disputes, and despite the continued assurances from UNSCEAR and WHO  that all is well, we still don’t know for certain yet, but sadly ‘zero’ deaths seems optimistic.