Quantifying Dose from External Irradiation-Tools for Use on Free-Ranging Wildlife

Thomas HINTON, IER
Toshiro WADA, IER
Hiroko ISHINIWA, IER
Kei OKUDA, Tokyo Univ. of Ag. & Tech
Jim BEALSEY, University of Georgia, USA

OUTLINE of TALK
• Need for improved radiation dosimetry with wildlife• Passive dosimeters (TLD, OSL)
• New tool: GPS-electronic dosimeter• Electronic Spin Resonance of teeth for life time dose estimates• Molecular methods (frequency of dicentrics)• Dose – Effects and challenges in determining environmental risks from radiation exposuresAnimals can receive a radiation dose from:(1) ingesting contaminated food or water,(2) inhaling radioactive material, or(3) external irradiation

Accurate quantification of dose isamong the greatest challenges in fieldresearch of free-ranging animals

Dose is the measurement most lacking in many of thecontroversial papers regarding radiation effects to wildlife at
Chernobyl and Fukushima

Current models do not assess external dose realistically because they do notconsider an animal’s spatial and temporal use of habitats, or the habitat’s large
heterogeneity in levels of radioactive contamination

Polessye StateRadiation EcologicalReserve, BELARUS

2160 km 2Home range~ 100 km 2

Determining external dose is particularly challenging because radiation deposition
is not uniform among the many, many different habitats available to animals….

Thermoluminescent Dosimeters (TLDs)…
• Integrate dose over the entire time that they areon the animal• Recapture of the animal and laboratory analyses

of TLD is required3580 fish captured,tagged andreleased;

29% recaptured

Woodhead, 1973

T. WADAOKUMA TOWN---Large Japanese Field Mice(Apodemus specious)• Age of mouse estimated from tooth characteristics• Internal dose estimated from Cs-134 and Cs-137 concentrations in tissues• External dose estimated from OSL nanoDot dosimeter

Lifetime dose ranged from 52 to 340 mGy;
External doses 5 to 95 times > than Internal.

With Vectronic Aerospace and Mirion, we produced a new scientifictool that permits an animal’s location and short-term integrated
dose to be periodically sent, via satellite, to the investigatorWe merged two existing
technologies (Wildlife Tracking
Collars that use GPS) andElectronic Dosimeters (designed for
determining dose to humans)

Hinton, et al. (2015) JER 145:58-65

Developed a whole-body, field assay
method to determine gamma emitting
radionuclides internal to live animals
CZT spectroscopy Cd, Zn and Te composition

Field tested the GPS-dosimeter
and whole body assay methods
at Chernobyl

Chernobyl
WolvesCollaboration with
Dr. Jim BeasleyChernobyl
WolvesCollaboration with
Dr. Jim BeasleyChernobyl
WolvesCollaboration with
Dr. Jim BeasleyObtained a GPS location and dose every 35 minutes

Chernobyl
WolvesCollaboration with
Dr. Jim Beasley

GPS track of a
Chernobyl wolf over
400 km2 area

GPS tracks of
8 ChernobylWolves

Collaboration withDr. Jim BeasleyObtained dose rate dataand whole-bodyradiocesium

concentrations of theanimals, as a function ofradionuclide deposition
data.

TITRE DE LA PRESENTATION - DATE DE LA PRESENTATION

20/20

野生イノシシ"グレース"の1ヶ月間にわたる外部線量率測定
External dose rate measurements from wild boar, “Grace”, over a one-month period

Dr. Kei Okuda

Hourly intervals

Wild Boar “Grace”….. living 4 km from the FDNPP

野生イノシシ"グレース"の生息地は福島第一原子力発電所から４ km

Hourly intervals

Life Time Dose to Boar
Electron Paramagnetic Resonance Dosimetry

Technique Development Phase福島大学環境放射能研究所
Ecosystems

群集Communities
Populations
Individual
KELLY CUNNINGHAM,
Veterinarian student,
Colorado State University

Tissues

Cells 細胞細胞
Cells

生態系

個体群

個体

組織

Chromosome damage in cells of wild boar exposed to radiation

放射線被ばくした野生イノシシの細胞内の染色体損傷

Molecules DNA分子DNADNA
Molecules
DNA分子電離放射線による染色体のDNA損傷
Ionizing Radiation Causes DNA Damage in Chromosomes

二動原体染色体
Dicentric Chromosomesケリーは、イノシシの染色体と動原体を蛍光染色する高度な方法を用いて、損傷した染色体と二動原体染色体を可視化している。

Kelly uses sophisticated methods that paint chromosomes, and their centromeres….making iteasier to visualize the damaged ones and those that have formed dicentrics .

細胞１００個に対する二動原体染色体の平均発生数
Average Number of Dicentric Chromosomes per 100 cells

3.00
Dicentric Chromosomes (per 100 cells)

細胞１００個に対する二動原体染色体

3.50

2.50

2.00

1.50

1.00

0.50

0.00
High Exposure Rate

高線量被ばく ；Low Exposure Rate

低線量被ばく ；Unexposed

被ばく無しCHALLENGES 課題

野生生物の状況については、ほとんど知られていない
Because of a lack of appropriate data,
there is not an international consensus
on how best to measure radiologicalimpacts to wildlife

Ecosystems
Communities

Populations
Individual

関連性は？？
relevance

Tissues
Cells

個体組織細胞DNA Molecules
DNA分子
DNAMolecules
分子

個体群

生態系
群集

適切なデータがないため、野生生物に対する放射線影響に関する最適な測定方法についての国際的な合意はない

CHALLENGES 課題

Fundamental differences in human and ecological risk analyses .

人間と生態系とのリスク分析における基本的な違い
typeunit of observation, what
we are trying to protect

タイプ

観測単位

終了点

人間

個人

生涯発癌リスク

individual

lifetime cancer risk

Humanendpoint, what we measuredose-response

線量反応
確立されているrelationships
established

生態系

多様

多様

Ecologicalvaries

variesnot established

死亡,再生,染色体損傷

慢性の,低レベル被ばく
放射線への個体,個体群,群集,
生態系
individual,population,community,ecosystem??

??
mortality, reproduction,chromosome damage

確立されていない??
for chronic, lowlevel exposure
to radiation

6

Future Work:
Research dose-effects
from chronic exposuresto radiation