PowerPoint

Medical Assistance for
the 23km Zone after
the Fukushima Dai-ichi Nuclear Disaster
The University of Tokyo, The Institute of Medicine
Minamisoma Municipal General Hospital,
Department of Internal Medicine
Dr. Masaharu Tsubokura
Contents
1.
2.
3.
4.
5.
Background Information
Internal Radiation Exposure Control
External Radiation Exposure Control
Indirect Health Effects
Conclusion
Present state of radioactive materials
5cm from
surface of the
soil
Bind tightly to dirt or mud
At first, there was no device (dosimeter) to measure the level of airborne
radiation
Tsubokura et al. Internal medicine 2012
Control of Radiation Exposure
5
External and Internal Radiation Exposure
Internal Radiation Exposure Control
(Whole Body Counter: WBC)
The program started in
July 2011 at
Minamisoma Munical General Hospital
Whole Body Counter (Fastscan) used today
Detection limit: 250 Bq/body
• Continuous monitoring of the internal
radiation exposure level since the disaster.
• The program is now mandatory for all the
students in Minamisoma and Soma cities.
Whole Body Counter (Babyscan) used today
Detection limit: 50 Bq/body
Prevalence of Internal Radiation Exposure (Cesium 137)
Location: Minamisoma City General Hospital
Duration: 2011/September/26-2012/March/31
Total Number of Participants: 7814 (above 16 years old)
Number of participants
6000
5229
Even the highest level of
internal radiation exposure
detected can be considered
“not so high”
5000
4000
3000
2000
1000
0
1338
495
1mSv/year
421
153 72 38 16 21
9
6
16
Radioactive
potassium
Bq/kg
Tsubokura et al. JAMA 2012
10
The possible reasons for the low
internal radiation exposure
• Relatively small size of the explosion
• Mandatory evacuation
• Strict food regulation
• The public had some knowledge about a nuclear
disaster (e.g., Chernobyl)
• Frequent “Radiation and health seminar”
However, these factors had significant negative effects on
the local communities
11
Prevalence of Internal Radiation Exposure
Location: Hirata Central Hospital
Duration: October/2011-November/2012
Sample size: 32,811 (above 16 years old)
A decline in the overall detection rates
for both adults and children
Proc. Jpn. Acad., Ser. B Hayano et al. 2013
Food inspection must continue
Prevalence of Internal Radiation Exposure (Cesium 137)
Location: Minamisoma City General Hospital
Duration: 2012/April/1-2012/September/30
Total Number of Participants: 7814 (above 16 years old)
7000
6420
Number of Particiapnts
Above20Bq/Kg
0.16%（2.28%）
6000
5000
Above 30Bq/Kg
0.11%（0.87%）
4000
Above40Bq/Kg
0.09%（0.40%）
Polarization in the
levels of internal
radiation exposure
3000
Above 50Bq/Kg
0.04%（0.20%）
2000
1000
239
0
263
35
9
2
1
1
1
2
1
3
Bq/Kg
*(
) implies the percentage of the first screening program （9/26～3/31）
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How we can reduce the risk of internal exposure…
Avoid regularly eating types of foodstuffs
which are under shipment control*, without
radiation inspection.
*As of December 22, 2014, following foodstuff have been regulated:
(1) Mushrooms
(2) Edible wild plants (e.g., butterbur, and aralia sprouts)
Most important is a type of foodstuff, NOT production area
(Tsubokura et al. PLOS ONE. 2014)
15
Food intake at Minamisoma City
Total Number of Participants: approx.3000
Q. How are you obtaining the following food products (Multiple answers)
100
Despite of their dietary habits,
the detection rate continued to decline.
90
Percentage（％）
80
70
60
50
40
30
20
10
0
Rice
米
Meat
肉
Fish
魚
Vegetable
野菜
Mushrooms
キノコ類
Milk
牛乳
In the supermarket with
consideration of production area
スーパーで購入し、産地を選ぶ
スーパーで購入するが、産地は選ばない
In the supermarket without consideration of production area
地元または家庭でとれたものを用いる
From home gardens
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External Radiation Exposure Control
(Glass badges)
Measures the periodic average level of
external exposure
Measures the hourly average level of
external radiation exposure
Air-Contamination Trends
(Source: Ministry of Education, Culture, Sports, Science and Technology)
18
Air-Contamination Trends
(2013.11.19)
40km
Soma city
30km
Minamisoma city
(Source: Ministry of Education, Culture, Sports, Science and Technology)
19
Air-Contamination Trends
(2013.11.19)
40km
Soma city
30km
Minamisoma city
(Source: Ministry of Education, Culture, Sports, Science and Technology)
20
Air-Contamination Trends
(2013.11.19)
40km
Soma city
30km
Minamisoma city
(Glass Badge: GD-450, Chiyoda Technol Corp.)
(Source: Ministry of Education, Culture, Sports, Science and Technology)
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Dose distribution in Soma city (Oct. – Sep.)
(％）
45.0
2011 (n=4,010)
40.0
35.0
30.0
26.0
25.0
25.2
20.0
16.1
15.0
10.0
5.0
14.9
6.9
3.9
3.5
1.5
0.7
0.5
0.8
0.0
Annual additional effective dose (mSv) ≒Personal Dose Equivalent: Hp(10)
Dose distribution in Soma city (Oct. – Sep.)
(％）
45.0
2011 (n=4,010)
40.0
38.2
2012 (n=4,135)
35.0
28.7
26.0
25.2
30.0
25.0
20.0
16.1
15.0
13.0
14.9
12.8
10.0
5.0
0.0
6.9
3.9
4.2
1.7
3.5
0.7
1.5
0.3
0.7
0.1
0.5
0.0
0.8
0.2
Annual additional effective dose (mSv) ≒Personal Dose Equivalent: Hp(10)
Dose distribution in Soma city (Oct. – Sep.)
(％）
45.0
42.5
40.0
42.4
2011 (n=4,010)
38.2
2012 (n=4,135)
35.0
2013 (n=3,173)
28.7
26.0
25.2
30.0
25.0
20.0
16.1
15.0
13.0
14.9
11.2
12.8
10.0
5.0
6.9
3.9
2.8
4.2
0.9
0.0
1.7
0.2
3.5
1.5
0.7
0.2
0.1
0.1 0.7
0.0
0.0 0.3
0.0 0.5
0.0 0.8
0.0
Annual additional effective dose (mSv) ≒Personal Dose Equivalent: Hp(10)
25
Decontamination Cost: Approx. £ 5 billion
26
Level of exposure is low, but,,,,
27
Soma High School &
Fukushima High School
Q. Things I would like to
know about radiation
We no longer discuss about radiation issues, but there are
still students with self-destructive comments.
Contents
Future health effects
#
16
Water & seafood safety
How long will it take until we can live without worrying
about radiation?
The amount of radiation we are currently exposed to
6
The actual contamination level
3
Things we need to be careful of
3
Differences between internal and external exposure
2
Vegetables/food products safety
2
Methods on how to get rid of radiation
2
Issues on decontamination & release of the No Entry Zone
2
Differences between Chernobyl and Hiroshima
2
Safety of areas around my house
Differences between artificial and naturally occurring
radiation
Methods on how to get rid of radiation from our body
1
Ways to read radiation level in units.
1
Differences between radiation in Japan and abroad
1
5
4
1
1
Other comments:
• I am not interested. I do not see a
point in discussing about
something that had happened
more than two years ago.
• I am not interested. How the
knowledge on radiation would help
us get rid of the radiation we have
been already exposed to?
• I do not really know about it, but I
think I would probably die of
cancer.
• I do not know if we will be healthy
in ten years.
The purpose of information sharing
① To prevent loss of self-confidence
（For them to continue their normal daily life)
② To prevent isolation
（Socially, Economically, Physically, Physiologically
etc…)
It is important to share the information (e.g., the
result on screening test), and to provide
additional support/service.
Current Challenges
1. To provide frequent feedbacks to the residents about the
results of each screening program
2. To establish a sustainable screening system
3. Residents have low interest and understanding towards the
importance of frequent checkup
4. To evenly share information amongst the people involved in
all projects.
5. To combine the WBC results to the other related tests
Facilities holding a
WBC
W
W
W
W
Thank you
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