Is the Food in Japan Safe?
Talk given at the American Chamber of Commerce Japan, Tokyo (starts 5:30pm, Tokyo)
by Professor Wade Allison, Oxford
Professor Akira Tokuhiro, University of Idaho 3 October 2011
Professor Akira Tokuhiro
• Akira Tokuhiro, Ph.D.; [email protected] • Professor of Nuclear and Mechanical Engineering • Born in Tokyo, educated in the U.S. • 20+ years of international nuclear engineering R&D, research,
teaching experience • Tokuhiro and co-authors, Technical Lessons Learned from Fukushima,
Valve World, Oct 2011. Fukushima Dai-ichi: Initial Technical Lessons, Nuclear Exchange, May 2011. Updated Technical Lessons Learned 100 Days After Quake, Tsunami at the Fukushima Dai-ichi, Units 1-6, Nuclear Power Plant, July 2011.
• University of Idaho • 1776 Science Center Drive
Idaho Falls, Idaho USA 83402 • T: +1- 208-533-8102
F: +1-208-526-8455
2
Post-Fukushima Nuclear Power Plant Accident, Challenges in the Days Ahead
3
Challenges in Short (assuming cold shutdown established)
Time: years to come
Expense: multi-year expenses
Technical: achievable; cleanup is larger scale than TMI; little to no experience in Japan
Safety: aftershock possible, NPS degradation (weathering), access difficult
Environmental : effluent release mitigation; onsite and offsite mitigation, water & airborne effluents
Waste management: interim waste storage plan & implementation in conjunction with or ahead of cleanup
Workforce: large workforce needed; need to monitor exposure and post-exposure health
4
Contamination map, ‘hot-spots’
http://mdn.mainichi.jp/mdnnews/news/20110914p2a00m0na013000c.html
Contamination is distributed
5
slide 6
Wade Allison, Akira Tokuhiro in Minami Soma, Iitate, Namie
Hotspots
Hot spot mapping is not being consistently done throughout Japan yet. It needs to be and the results need to be made public.
People exposed to hot spots need to be tested for radiation exposure.
Some villages/cities will be taken off the lists, whereas others will be added.
Clean-up (top soil removal) needs to happen systematically to make areas safe.
Locations for safe redeployment of soil must be established.
7
Food Safety, Matter of Risk
Recent O157, O111 E-coli outbreak and deaths at chain restaurant Eating ‘fugu’, at licensed and unlicensed restaurants Hg-ladened tuna Genetically-modified corn, soy beans
http://www.google.com/imgres?q=mercury+in+tuna&um=1&hl=en&gl=us&tbm=isch&tbnid=S2a4j6FMeE8r6M:&imgrefurl=http://news.3yen.com/2010-04-26/death-metal-sushi/&docid=CCTj8e3PCf8O5M&w=302&h=350&ei=222CTpifNc-CsgLZp_iIDw&zoom=1&biw=1280&bih=568&iact=rc&dur=394&page=1&tbnh=139&tbnw=116&start=0&ndsp=19&ved=1t:429,r:3,s:0&tx=44&ty=79 8
What is Risk? Risk is relative to the individual, the group, societal
subgroups and the country itself
Risk involves ‘perception of benefit’ vs. ‘perception of risk’
Therefore, ‘benefit’ and ‘risk ’ are constantly at issue
Examples of risk: •Eating fugu (puffer fish) •Eating mercury-ladened fish or eating radiation-ladened fish •Smoking cigarettes and drinking alcohol •Flying on commercial airline •Driving or being a passenger in a car
9
Risk map – U.S. vs. Japan
10
Risk and Resiliency
The biological make-up of the individual. Each of us can and does accommodate toxins differently.
“Resiliency” broadly defined is the ability of the body to accommodate and mitigate the negative health effects of toxins to which one is exposed.
One tries to minimize risk; however, there is a different degree of resiliency in each of us.
Health effects from ingested toxins may appear immediately to many years later; all types of cancer can be cause by exposure to toxins.
Sometimes, (low) risk and (high) resiliency is not enough to overcome cancer; many times it is sufficient
11
Metrics to Consider in Exposure to Radiation
Time(T): How long/how short is the exposure?
Number/magnitude(N): How large/small is the amount of radiation?
Length/area(L, L x L): How large/small an area is contaminated?
Energy (E): What is the energy of the ionizing radiation?
Distribution(D): Where is contamination?
12
Radiation and Reason, Akira Tokuhiro
There are many risks in daily life; while voluntary risk is acceptable, involuntary is not; remember the personal balance between perception of benefit vs. risk
There are many toxins that one ingests in today’s polluted word; 13% (2007, Wikipedia) of all world deaths are from cancer; don’t single out radiation; human body has ability to accommodate toxins; the body is resilient over a lifetime; each individual is different; science does not understand everything
Radiation detection and measurement is well-developed but more sensitivity means higher-end instruments; lower-end can be misleading; I encourage confirmatory, independent measurement; work with radiation detection & measurement experts
Health effects studies on children & women of child-bearing years are very difficult to do; conservatism should not be ‘1/10th’; we simply do not know the complete health effects
13
http://ajw.asahi.com/article/0311disaster/opinion/AJ2011092810124
Radiation expert believes more food testing needed – Prof. Emeritus, Ikuro Anzai
“…central government said it would not allow food to reach the market if it contained radiation that exceeded provisional standards, concerns are being raised as to whether that promise is being kept. The most important issue right now is that the sense of trust among consumers is being hurt. “
14
Action Plan, Food Safety
For the individual Fear is factor Be vigilant; cross-check information Learn ‘risk and resiliency’; “TLEDN” Re-establish trust from all parties; communication and substantiated commitment
15
Contact information
Dr. Akira Tokuhiro Professor, Mechanical & Nuclear
Engineering University of Idaho
1776 Science Center Drive Idaho Falls, ID 834-2-1575 USA
+1-208-533-8102 www.if.uidaho.edu
Post-Fukushima, Anticipated questions Radiation Discussion Points:
Q1:Hot spot mapping - At what point should evacuations still be considered A: per hotspot maps (generally NW areas) if and when cleanup and remediation is to take place and if annual dose (as set) is exceeded
Q2: Exposure on March 15 and March 21 - What were they exposed to and should they be concerned? A: need to check list of radio-nuclides to assess whether exposure is of concern (is there data, has it been announced?)
Q3: How long will decontamination take and how long for the plant to be decommissioned? A: see previous slide for plant; site vs. off-site
Q4: What is the effect of long-term, low-level exposure? A4: Wade Allison will address this.
Q5:How can people feel assured about exposure for children? A5: assurance is not so much about science but fear of the unknown; regardless of the science, parents may decide on the side of conservatism with respect to children.
Q6: Why is Iodine 131(8d)/Cesium134(2y)/137(30y) only measured and not other radionuclides? A6: if other isotopes are present, in principle, they can be measured. Iodine and cesium are volatile, Effects of I-131 may turn up as thyroid cancer; Cs-134/137 accumulate in muscles – may be of concern. T, N of exposure is key
17