Antinuclear

Jim Green’s comprehensive analysis of the World Health Organisation’s report on Fukushima’s radiation health effects

What to make of the WHO report on health risks from the Fukushima disaster?  Summary and comments from Jim Green jim.green@foe.org.au 2 March 2013, 

 World Health Organization, February 2013, ‘Health risk assessment from the nuclear accident after the 2011 Great East Japan Earthquake and Tsunami based on a preliminary dose estimation’

http://www.who.int/ionizing_radiation/pub_meet/fukushima_report/en/index.html

And a related report released at the same time:

‘Preliminary dose estimation from the nuclear accident after the 2011 Great East Japan Earthquake and Tsunami’

In a nutshell

The report is important because of WHO’s stature, and because it acknowledges the likelihood of increased cancer incidence and mortality from radiation exposure from the Fukushima disaster (whereas many nuclear apologists claim otherwise).

What the WHO report does

1. It pulls together lots of information on radiation exposures from the Fukushima disaster.

As you can imagine there is a lot of guess work. And the results are necessarily preliminary because radiation exposure from fallout from the accident is ongoing.

The report states (section 5 of the dose estimation report): “The radiation doses in this report represent a preliminary assessment of doses for the first year after the Fukushima accident based on data available to the panel up to September 2011. Doses are provided for different populations by age and geographical location.”

So it only considers radiation doses in the first year. It states: “The experience of the Chernobyl accident was that about 30% of the lifetime dose was delivered during the first year and about 70% during the first 15 years. On the basis of environmental activity concentration data, it can be expected that the fraction of the lifetime dose beyond the first year will be lower for the Fukushima Daiichi nuclear power plant accident than for the Chernobyl accident, due to the greater influence of the shorter-lived 134CS (half-life two years) compared to 137CS (half-life 30 years).”

2. It uses information / estimates on radiation exposure to predict increases in cancer incidence risks

According to the WHO’s FAQ, “the risks were calculated taking into account population radiation exposure over lifetime, assuming that risks are proportional to doses (i.e. “linear non-threshold ” /LNT model), and without applying a factor often used when the dose is low or delivered over a long period of time (i.e. dose and dose rate effectiveness factor /DDREF).”

The FAQ justifies that choice on the basis that the “assumptions and methodological choices in this assessment were consciously made to minimize the possibility of underestimating health risks, i.e. conservative assumptions were made.”

However a conservative approach would consider the possibility that LNT underestimates true risks. For example a 2006 report from the U.S. National Academy of Sciences states, “combined analyses are compatible with a range of possibilities, from a reduction of risk at low doses to risks twice those upon which current radiation protection recommendations are based.” (BEIR VII, 2006)

What the WHO report does NOT do

The WHO report does not consider cancer incidence and mortality statistics to see if there is a significant increase that can be attributed to Fukushima. Presumably the reason for this is that no significant increase could possibly be detected for various reasons such as the long latency period of most cancers, and the impossibility or near-impossibility of determining the impact of the Fukushima accident given that cancer incidence and mortality figures are being driven up and down by a multitude of other factors.

The Executive Summary states:

This report does not include:

• doses within 20 km of the Fukushima site, since most people in the area were rapidly evacuated. While some dose may have been received prior to evacuation, such assessment would have required more precise data than were available to the panel.
• doses to workers, because the evaluation of occupational radiation exposure requires a dosimetric approach different from the one used for members of the public. The assessment conducted by the WHO Health Risk Assessment (HRA) Expert Working Group will incorporate information on workers’ exposure provided by the Government of Japan.

The report provides estimates of radiation exposure within and beyond Japan, but it does not give any estimates regarding the number of people who fall into each category of radiation exposure.Therefore it is not possible from this WHO study to come to any estimate as to the total number of cancer deaths that could arise from the Fukushima disaster.

Other preliminary studies have attempted to estimate the long-term death toll. These include a “very preliminary order-of-magnitude guesstimate” of “around 1000” fatal cancers (von Hippel, 2011), and a Stanford University study that estimates “an additional 130 (15–1100) cancer-related mortalities and 180 (24–1800) cancer-related morbidities incorporating uncertainties associated with the exposure−dose and dose−response models used in the study” (Ten Hoeve and Jacobson, 2012).

Those estimates / guesstimates could underestimate the true death toll. However claims from various sources (certainly not this WHO report) that the death toll will reach hundreds of thousands should be ignored or, better still, actively contested because i) they are implausible and ii) they are presumably causing some distress in Japan (though only a tiny fraction of the distress caused by Japan’s corrupt nuclear industry and its many accomplices including uranium mining companies in Australia − if not for their failings and wilful negligence the accident wouldn’t have happened in the first place).

What the WHO report finds − cancer incidence estimates

 The media release accompanying the report provides the following summary:

“The primary concern identified in this report is related to specific cancer risks linked to particular locations and demographic factors,” says Dr Maria Neira, WHO Director for Public Health and Environment. “A breakdown of data, based on age, gender and proximity to the nuclear plant, does show a higher cancer risk for those located in the most contaminated parts. Outside these parts – even in locations inside Fukushima Prefecture – no observable increases in cancer incidence are expected.”

 In terms of specific cancers, for people in the most contaminated location, the estimated increased risks over what would normally be expected are:

• all solid cancers – around 4% in females exposed as infants;
• breast cancer – around 6% in females exposed as infants;
• leukaemia – around 7% in males exposed as infants;
• thyroid cancer – up to 70% in females exposed as infants (the normally expected risk of thyroid cancer in females over lifetime is 0.75% and the additional lifetime risk assessed for females exposed as infants in the most affected location is 0.50%).

 For people in the second most contaminated location of Fukushima Prefecture, the estimated risks are approximately one-half of those in the location with the highest doses.

 The report also references a section to the special case of the emergency workers inside the Fukushima NPP. Around two-thirds of emergency workers are estimated to have cancer risks in line with the general population, while one-third is estimated to have an increased risk.

 The almost-200-page document further notes that the radiation doses from the damaged nuclear power plant are not expected to cause an increase in the incidence of miscarriages, stillbirths and other physical and mental conditions that can affect babies born after the accident. 

The Executive Summary provides a bit more detail (and of course the full report provides lots more detail):

In the two most affected locations of Fukushima prefecture, the preliminary estimated radiation effective doses for the first year ranged from 12 to 25 mSv. In the highest dose location, the estimated additional lifetime risks for the development of leukaemia, breast cancer, thyroid cancer and all solid cancers over baseline rates are likely to represent an upper bound of the risk as methodological options were consciously chosen to avoid underestimation of risks. For leukaemia, the lifetime risks are predicted to increase by up to around 7% over baseline cancer rates in males exposed as infants; for breast cancer, the estimated lifetime risks increase by up to around 6% over baseline rates in females exposed as infants; for all solid cancers, the estimated lifetime risks increase by up to around 4% over baseline rates in females exposed as infants; and for thyroid cancer, the estimated lifetime risk increases by up to around 70% over baseline rates in females exposed as infants. These percentages represent estimated relative increases over the baseline rates and are not estimated absolute risks for developing such cancers. It is important to note that due to the low baseline rates of thyroid cancer, even a large relative increase represents a small absolute increase in risks. 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. These estimated increases presented above apply only to the most affected location of Fukushima prefecture. For the people in the second most affected location, the estimated additional lifetime cancer risks over baseline rates are approximately one-half of those in the highest dose location. The estimated risks are lower for people exposed as children and adults compared to infants.

 In the next most exposed group of locations in Fukushima prefecture, where preliminary estimated radiation effective doses were 3–5 mSv, the increased lifetime estimates for cancer risks over baseline rates were approximately one-quarter to one-third of those for the people in the most affected geographical location.

 Among Fukushima Daiichi nuclear power plant emergency workers, the lifetime risks for leukaemia, thyroid cancer and all solid cancers are estimated to be increased over base-line rates, based upon plausible radiation exposure scenarios. These scenarios and their corresponding estimated risks are detailed in the body of this report. A few emergency workers who inhaled significant quantities of radioactive iodine may develop non-cancer thyroid disorders.

 Indirect deaths

The WHO report is silent on indirect deaths, but these should be considered, especially those resulting from the failure of TEPCO and government authorities to develop and implement adequate emergency response procedures. A September 2012 Editorial in Japan Times notes that 1,632 deaths occurred during or after evacuation from the triple-disaster; and 160,000 of the 343,000 evacuees were dislocated specifically because of the nuclear disaster (Japan Times, 2012). A January 2013 article in The Lancet notes that “the fact that 47% of disaster-related deaths were recognised in Fukushima prefecture alone indicates that the earthquake-triggered nuclear crisis at the Fukushima power plant caused extreme hardship for local residents.” (Ichiseki, 2013)

Non-cancer health effects – hereditary, psychological etc.

According to the WHO’s FAQ:

8. What about risks of birth defects due to the exposure of unborn children? Based on the low doses no increases in miscarriages, stillbirths or birth defects are expected as a result of prenatal radiation exposure from the accident.

 

9. What about health risks for power plant emergency workers? The greatest estimated risks are for a few emergency workers who received high doses to the thyroid gland (thyroid cancer risk). There may be an increased long-term risk of circulatory diseases among workers with the highest exposure levels.

 

10. Will future generations be affected? A risk of radiation-induced hereditary effects has not been definitively demonstrated in human populations. Based on animal data, any risk of hereditary effects for the offspring of those who were exposed before they have conceived children is considered to be much lower than the additional lifetime risk of cancer assessed for the individuals exposed (about ten times lower).

 

The WHO report states (p.89): “In addition to the doses, health monitoring and surveillance of people exposed to low radiation doses necessitates consideration of legal, social, economic and psychological factors, which go beyond the scope of the present report.”

 

Needless to say, the Fukushima disaster has caused an immense amount of suffering, particularly for the 160,000 evacuees. As the Nuclear Accident Independent Investigation Commission report notes, the Fukushima disaster was the result of “collusion between the government, the regulators and TEPCO” and evacuees “continue to face grave concerns, including the health effects of radiation exposure, displacement, the dissolution of families, disruption of their lives and lifestyles and the contamination of vast areas of the environment.” (NAIIC, 2012)

What the WHO report finds − radiation doses

In a nutshell (section 5 of the dose estimation report: Summary and conclusions):

 

• In Fukushima prefecture the estimated effective doses are within a dose band of 1−10 mSv, except in two of the example locations where the effective doses are estimated to be within a dose band of 10–50 mSv.
• In prefectures neighbouring Fukushima, the estimated effective doses are within a dose band of 0.1−10 mSv, and in all other prefectures the effective doses are estimated to be within a dose band of 0.1−1 mSv.
• In the rest of the world estimated effective doses are less than 0.01 mSv, and are usually far below this level.

More detail from section 3.3.1 of the dose estimation report:

 Estimated effective doses

• Of the example locations considered in Fukushima prefecture, several are in the area 20–30 km from the site where characteristic effective doses in the first year, to all age groups, are estimated to be in the dose band of 10–50 mSv. The dominant pathway in these locations is estimated to be external dose from ground deposits but there are also contributions from the other exposure pathways. In these locations, only the first four months of exposure from external dose have been included as it has been assumed that relocation would have occurred at that time.
• At other locations considered as examples in Fukushima prefecture, the characteristic effective doses in the first year, to all age groups, are estimated to be in the range 1−10 mSv. In these locations the major exposure pathways are external dose from ground deposition and ingestion doses.
• In prefectures neighbouring Fukushima, characteristic effective doses in the first year, to all age groups, are estimated to be in the dose band of 0.1–10 mSv. This wider range of dose band for these neighbouring prefectures reflects the wide variation in deposition levels across these areas. The dominant pathway here is estimated to be external dose from ground deposits.
• In other Japanese prefectures, characteristic effective doses in the first year, to all age groups, are estimated to be in the dose band of 0.1–1 mSv, with the dominant pathway being food ingestion. In countries neighbouring Japan, characteristic effective doses in the first year, to all age groups, are estimated to be less than 0.01 mSv, with the dominant pathway being ingestion of locally-produced food.
• For the rest of the world, characteristic effective doses in the first year, to all age groups, are also estimated to be less than 0.01 mSv, and are usually far below this level. Again, the dominant pathway is ingestion of locally produced food.

 

The dose estimation report discusses thyroid doses in section 3.3.2:

• For most of Fukushima prefecture, the estimated characteristic thyroid doses in the first year, to all age groups, are in the dose band of 10–100 mSv. The exception is Namie town in Futaba county, which lies partially within the 20km restricted area and the deliberate evacuation area (Figure 1). Dose estimates were calculated for the part of the town located in the area 20–30 km from the site, showing thyroid doses to infants within the dose band of 100−200 mSv. In several of the most affected locations, the doses were estimated only for the first four months, as relocation was assumed to have occurred at that time. It should be noted that a significant contributor to thyroid

References

BEIR VII − US National Academy of Sciences, Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation, 2006, ‘Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2’, www.nap.edu/catalog.php?record_id=11340

Ichiseki, Hajime, 19 January 2013, ‘Features of disaster-related deaths after the Great East Japan Earthquake’, The Lancet, Vol.381, Issue 9862, www.thelancet.com/journals/lancet/article/PIIS0140-6736%2813%2960091-4/fulltext

Japan Times, 19 September 2012, Editorial: ‘Slow road to reconstruction’,www.japantimes.co.jp/text/ed20120919a1.html

NAIIC, 2012, ‘The Official Report of the Fukushima Nuclear Accident Independent Investigation Commission’, http://warp.da.ndl.go.jp/info:ndljp/pid/3856371/naiic.go.jp/en/

 

Ten Hoeve, John E., and Mark Z. Jacobson, 2012, ‘Worldwide health effects of the Fukushima Daiichi nuclear accident’, Energy and Environmental Science, June, www.stanford.edu/group/efmh/jacobson/TenHoeveEES12.pdf

 

von Hippel, Frank, 2011, ‘The radiological and psychological consequences of the Fukushima Daiichi accident’, Bulletin of the Atomic Scientists, September/October, vol.67 no.5,http://bos.sagepub.com/content/67/5/27.abstract

 

March 1, 2013 - Posted by Christina Macpherson | Uncategorized