Regional Distribution of Fukushima Thyroid Cancer Cases (Confirmed and Suspected) Analyzed by Citizen Scientists

The first round of thyroid examination concluded in March 2014, and its results are nearly complete, except for some of the secondary examination results which were still not available as of August 24, 2014. Fukushima Medical University denies any regional difference in the incidence of thyroid cancer amongst Fukushima children and considers it unlikely that the current incidence of cancer is related to radiation exposure.  Although it might not be possible to epidemiologically assess the radiation health effects until the second round of thyroid examination is finished at the end of March 2016, the currently available data could still be analyzed in more detail.

As the nature of Japanese language allows significant amounts of information to be shared in a tweet using 140 letters, there has been an active discussion going on regarding the thyroid examination results on Twitter. When the results are released by Fukushima Medical University, citizen scientists--some professionals and some concerned citizens--would closely examine and analyze them.

Some say it is all due to the screening effect, having nothing to do with radiation exposure, and they claim the thyroid examination is causing more harm by unearthing cancer that might have laid dormant until much later in life. Some go to the other extreme to claim all the cancer cases could be due to radiation exposure. And there are those who are somewhere in-between, calling for a careful data collection and analysis so as not to miss any cases which might potentially be related to radiation exposure.

Two of the Twitter users actively involved in the discussion, @pririn and @iPatrioticmom, analyzed the latest Fukushima thyroid ultrasound examination results, released n August 24, 2014. Rather than claiming definite radiation health effects, which at this point is difficult to do, they simply want to point out the need for proper analyses of data from the first round of examination. They admit that this analysis is not by any means a final one and that the data is not age adjusted.

The translation was assisted by @sitesirius and @niigatamama.

Original analysis in an Excel file: Japanese and English.


Tab 1: Regional distribution of confirmed and suspected thyroid cancer cases in 
Fukushima Prefecture

Based on Table 8 of "Thyroid Examination (Initial Screening)" provisional results


FY2011 target municipalities
FY2012 target municipalities
FY2013 target municipalities

No.City, Town, VillageNumber of primary examination participantsNumber of confirmed or suspected cancerProportion of confirmed or suspected cancerIncidence per 100,000
1Minamisoma南相馬市1078920.02%19
2Date伊達市1060620.02%19
3Tamura田村市632730.05%47
4Kawamata川俣町222120.09%90
5Namie浪江町324920.06%62
6Hirono広野町83800.00%0
7Naraha楢葉町115300.00%0
8Tomioka富岡町230210.04%43
9Okuma大熊町197310.05%51
10Futaba双葉町94900.00%0
11Iitate飯舘村94300.00%0
12Kawauchi川内村28010.36%357
13Katsurao葛尾村18300.00%0
Subtotal41813140.03%33.5
14Fukushima福島市47336120.03%25
15Koori桑折町185700.00%0
16Kunimi国見町142900.00%0
Subtotal50622120.02%23.7
17Nihonmatsu二本松市884650.06%57
18Motomiya本宮市523330.06%57
19Koriyama郡山市53962230.04%43
20Shirakawa白河市1080560.06%56
21Miharu三春町271710.04%37
22Otama大玉村137220.15%146
23Ten-ei天栄村87800.00%0
24Nishigo西郷村361810.03%28
25Izumizaki泉崎村115610.09%87
Subtotal88587420.05%47.4
26Soma相馬市504600.00%0
27Shinchi新地町110500.00%0
Subtotal615100.00%0
28Iwakiいわき市47759190.04%40
Subtotal47759190.04%39.8
29Sukagawa須賀川市1153240.04%35
30Kagamiishi鏡石町194700.00%0
31Yabuki矢吹町245200.00%0
32Ishikawa石川町207810.05%48
33Yamatsuri矢祭町77400.00%0
34Asakawa浅川町106700.00%0
35Tanagura棚倉町225610.04%44
36Hanawa塙町121000.00%0
37Ono小野町131700.00%0
38Furudono古殿町79000.00%0
39Nakajima中島村80100.00%0
40Hirata平田村82410.12%121
41Samegawa鮫川村50300.00%0
42Tamakawa玉川村98400.00%0
Subtotal2853570.03%24.5
43Kitakata喜多方市571000.00%0
44Aizuwakamatsu会津若松市1463250.03%34
45Minamiaizu南会津町180300.00%0
46Kaneyama金山町13600.00%0
47Mishima三島町12900.00%0
48Shimogo下郷町68810.15%145
49Nishiaizu西会津町63800.00%0
50Tadami只見町49200.00%0
51Inawashiro猪苗代町187110.05%53
52Bandai磐梯町41300.00%0
53Aizumisato会津美里町254700.00%0
54Aizubange会津坂下町207410.05%48
55Yanaizu柳津町37500.00%0
56Hinoemata檜枝岐村6100.00%0
57Showa昭和村10100.00%0
58Kitashiobara北塩原村38200.00%0
59Yugawa湯川村50710.20%197
Subtotal3255990.03%27.6

Incidence rate in adjacent municipalities, grouped together so each group consists of about 10,000 to 20,000 primary examination participants (age group is not controlled)
(Groups are shown in gradations of the color--blue, yellow, or green--assigned to each fiscal year's target municipalities in the table above).



Regional differences--up to 5 times between the FY2012 and FY2013 target municipality groups as shown below:

FY2012 Nihonmatsu, Motomiya and Otama, 64.7 per 100,000 (shown in red)
FY2013 Northern Hamadori and Southern Nakadori, 13.0 per 100,000 (shown in green--top and bottom of the map)





*****

Shown below is the same table as above, except with each fiscal year's target municipalities color-coded according to the map immediately below. Names of the municipalities are shown in English and numbers are assigned corresponding to the numbers shown in the leftmost column.

FY2011 target municipalities
FY2012 target municipalities
FY2013 target municipalities


No.City, Town, VillageNumber of primary examination participantsNumber of confirmed or suspected cancerProportion of confirmed or suspected cancerIncidence per 100,000
1Minamisoma南相馬市1078920.02%19
2Date伊達市1060620.02%19
3Tamura田村市632730.05%47
4Kawamata川俣町222120.09%90
5Namie浪江町324920.06%62
6Hirono広野町83800.00%0
7Naraha楢葉町115300.00%0
8Tomioka富岡町230210.04%43
9Okuma大熊町197310.05%51
10Futaba双葉町94900.00%0
11Iitate飯舘村94300.00%0
12Kawauchi川内村28010.36%357
13Katsurao葛尾村18300.00%0
Subtotal41813140.03%33.5
14Fukushima福島市47336120.03%25
15Koori桑折町185700.00%0
16Kunimi国見町142900.00%0
Subtotal50622120.02%23.7
17Nihonmatsu二本松市884650.06%57
18Motomiya本宮市523330.06%57
19Koriyama郡山市53962230.04%43
20Shirakawa白河市1080560.06%56
21Miharu三春町271710.04%37
22Otama大玉村137220.15%146
23Ten-ei天栄村87800.00%0
24Nishigo西郷村361810.03%28
25Izumizaki泉崎村115610.09%87
Subtotal88587420.05%47.4
26Soma相馬市504600.00%0
27Shinchi新地町110500.00%0
Subtotal615100.00%0
28Iwakiいわき市47759190.04%40
Subtotal47759190.04%39.8
29Sukagawa須賀川市1153240.04%35
30Kagamiishi鏡石町194700.00%0
31Yabuki矢吹町245200.00%0
32Ishikawa石川町207810.05%48
33Yamatsuri矢祭町77400.00%0
34Asakawa浅川町106700.00%0
35Tanagura棚倉町225610.04%44
36Hanawa塙町121000.00%0
37Ono小野町131700.00%0
38Furudono古殿町79000.00%0
39Nakajima中島村80100.00%0
40Hirata平田村82410.12%121
41Samegawa鮫川村50300.00%0
42Tamakawa玉川村98400.00%0
Subtotal2853570.03%24.5
43Kitakata喜多方市571000.00%0
44Aizuwakamatsu会津若松市1463250.03%34
45Minamiaizu南会津町180300.00%0
46Kaneyama金山町13600.00%0
47Mishima三島町12900.00%0
48Shimogo下郷町68810.15%145
49Nishiaizu西会津町63800.00%0
50Tadami只見町49200.00%0
51Inawashiro猪苗代町187110.05%53
52Bandai磐梯町41300.00%0
53Aizumisato会津美里町254700.00%0
54Aizubange会津坂下町207410.05%48
55Yanaizu柳津町37500.00%0
56Hinoemata檜枝岐村6100.00%0
57Showa昭和村10100.00%0
58Kitashiobara北塩原村38200.00%0
59Yugawa湯川村50710.20%197
Subtotal3255990.03%27.6


Tab 2: Incidence by municipality and March 15th plume

Incidence rate of each municipality and plume flow on March 15, 2011 analyzed by JAEA

Incidence rate per 100,000 (in red) in municipalities with more than 1,000 primary examination participants, superimposed on maps showing contaminated regions due to the March 15-16 radioactive plume, analyzed by JAEA

Sources: 
① Table 8 of "Thyroid Examination (Initial Screening) provisional results"
② "Formation of contaminated areas from the morning of March 15 to the afternoon of March 16" on page 16 of "Diffusion of Radioactive Iodine in the Environment: Based on the Model Calculation Results" by Masamichi Kayano, JAEA"

<Plume flow 1: March 15, 2011 from 6:00 am to 3:00 pm>


<Plume flow 2: March 15, 2011 from 3:00 pm to 9:00 pm>


<Plume flow 3: From 9:00 pm on March 15 to 6.00 am on March 16>




<Plume flow 1 to 3>


Tab 3: Incidence by municipality and soil contamination

Incidence rate of each municipality and soil contamination

Incidence rate per 100,000 (in red) in municipalities with more than 1,000 primary examination participants, superimposed on a map of radioactive cesium concentration in agricultural land











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