Key input for RP Culture

from JHPS

10th Feb. 2011

Japan Health Physics Society (JHPS)

CRIEPI, Japan

Takatoshi Hattori

Goals for RP Culture

To give visibility to the fundamentals of RP (science and values)

To promote radiation risk awareness To promote shared responsibility among practitioners,

operators, regulators and management To maintain the RP heritage To facilitate its transmission To improve the quality and effectiveness of RP To improve communication with society To enhance the visibility of RP in our societies

2

Ref. IRPA website( http://www.irpa.net/images/stories/2010/irpa-rp-culture-krk-3-5-2010.ppt)

Needs for Visibility of RP

Probabilistic effect is a target of RP concerning public exposure below 1 mSv/y.

but, there is no actual and detectable health damage from exposure in the dose region below 1 mSv/y.

How can we ensure the visibility for such low probabilistic risk ?

3

One of solution: Background based approach

4

BG cancer mortality distribution

Ref.: National Cancer Center

Age-adjusted Cancer Mortality Rate under Age 75 by Prefectures (2005)

5

Scientific knowledge #1

BG cancer risk and assumed risk due to man-made radioactive nuclides

0.15

0.10

0.05

0.00

Pro

babi

lity

10-6

10-5

10-4

10-3

10-2

Detriment-adjusted nominal risk (/y)

BG cancer risk

Assumed maxium risk due to man-made

radioactive nuclides

Dose limit for public1 mSv/y

1of BG cancer risk

T. Hattori, Understanding of minute assumed risk due to radiation from man-made radioactive nuclides taking into consideration quantitative comparison with detriments based on background cancer mortality in Japan. Jpn. J. Health Phys., Vol. 45, No. 2, pp172-176 (2010).

http://www.jstage.jst.go.jp/browse/jhps

6

BG cancer incidence distribution

Radiation risk (detriment) in ICRP Pub. 103 was derived using database in Cancer Incidence in Five Continents Vol. VIII in International Agency for Research on Cancer (IARC).

The newest one is Cancer Incidence in Five Continents Vol. IX issued in 2009.

5 continents (6 regions) 60 countries (214 registries)

0 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mu

lativ

e p

rob

ab

ility

(%

)

7

Probability plot

World

　 σ ：3.8×10-4Mean： 1.6×10-3

0 1 10-3 2 10 -3 3 10 -3.01

.1

1

5102030

50

70809095

99

99.9

99.99

AsiaEuropeNorth America

Detriment-adjusted nominal risk (/y)

Cu

mu

lativ

e p

rob

ab

ility

(%

)

8

Probability plot (6 Continents)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

Asia Africa Oceania

Europe

Central　&　South　America

North　America

9

Probability plot (North America)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

0 100 1 10-3 2 10-3 3 10-3.01

.1

1

5102030

50

70809095

99

99.9

99.99

Detriment-adjusted nominal risk (/y)

Cu

mm

ula

tive

pro

ba

bilit

y (%

)

North　America

Canada United　States

5　x　10-5

assumed　risk　for　1　mSv/y

5　x　10-5

assumed　risk　for　1　mSv/y

5　x　10-5

assumed　risk　for　1　mSv/y

10

Scientific knowledge #2

BG cancer risk and assumed risk due to man-made radioactive nuclides

0.15

0.10

0.05

0.00

Pro

babi

lity

10-6

10-5

10-4

10-3

10-2

Detriment-adjusted nominal risk (/y)

Assumed maximum risk due to man-made

radioactive nuclides

SDW

Equivalent todose limit for public

1 mSv y-1

BG cancer risk

WorldAsia

Europe

SDASDESDN

NorthAmerica

Summary

Fundamentals of RP is currently too difficult and sometimes ambiguous for understanding by public.

RP experts should have more comprehensive understanding of radiation risk on a basis of their own countries’ data to improve communication with their societies.

If we can propose an international program using platform of RP Culture, RP system in the region below 1 mSv/y could be evolved by comprehensive background cancer risk approach.

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Thank you for your attention !Thank you for your attention !