Monday 4 March 2013

WHO Report

On Thursday the WHO issued a report. Full title: Health Risk Assessment from the nuclear accident after the 2011 Great East Japan Earthquake and Tsunami based on a preliminary dose estimation. The world's media screams 'Increased risk of Cancer in Fukushima'. Greenpeace accuses the WHO of being in cahoots with  the nuclear industry and says it 'shockingly downplays' the cancer impacts on the population. Whereas Mr Kanno, mayor of Iidate, says the projections are overestimates and not based on reality. He's a quietly spoken, moderate man who has skillfully steered his county through this disaster and when he objects, you sit up and take notice. But hang on a minute, what exactly is being said?

The WHO first assessed the preliminary dose (what we call hibaku 被爆 exposure) and then estimated lifetime doses and increased risk in all solid cancers combined, and also leukaemia, thyroid cancer and female breast cancer. The lifetime risks for both sexes were estimated at three different ages at exposure: 1 year (infant), 10 years (child), and 20 years (adult). Health risks for male emergency workers were estimated for three different ages (20 years, 40 years, and 60 years).

For most of us in Fukushima prefecture the results are reassuring. I quote, 'Outside the geographical areas most affected by radiation, even in locations within Fukushima prefecture, the predicted risks remain low and no observable increases in cancer above natural variation in baseline rates are anticipated.' Also, 'the estimated dose levels in Fukushima prefecture were also too low to affect fetal development or outcome of pregnancy and no increases, as a result of antenatal radiation exposure, in spontaneous abortion, miscarriage, perinatal mortality, congenital defects or cognitive impairment are anticipated'.

However, the report does point to an increase over baseline rates in areas where 'radiation effective doses for the first year ranged from 12 to 25 mSv' - Mr Kanno's county no less. The increases sound scary: around 6% over baseline rates for some cancers and a whopping 70% for thyroid cancer in females exposed as infants. But these are not absolute increases. As the report says, 'For example, the baseline lifetime risk of thyroid cancer for females is just three-quarters of one percent and the additional lifetime risk estimated in this assessment for a female infant exposed in the most affected location is one-half of one percent'. 

What Mr Kanno, the Japanese Ministry of Environment, and people here take issue with is the assumptions used. First, that people stayed in high radiation areas for four months. But people near the reactor were evacuated within days. Iidate county was evacuated in April. Only a handful of people refused to budge. Next, 'that consumers only ate food produced in the area where monitoring was implemented'. This is rubbish. There was a ban on all food in the exclusion zone and a prefecture-wide ban on milk, beef, spinach and other produce. 

The report does say that 'the dose estimates and assumptions used ...were deliberately chosen to minimize the possibility of underestimating eventual health risks' and I suppose it's good to have a few scare stories up your sleeve if you're trying to get people to prepare for the worst. But it doesn't do us any service, as we try and restore confidence in Fukushima.

Another moot point is the report's use of the Linear Model, i.e. that risks increase in direct proportion to the dose. I know this is controversial. You can download a copy of the report from the WHO website:  WHO Report

Already March. We had one warm day which fooled us into thinking spring was on the way but snow in the air again this weekend. My friend in Kitakata has two feet of snow. 
Love to you all

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