Aircrew and Spacecrew Radiation Exposure The Dangers of Getting High - - PowerPoint PPT Presentation

B.J. Lewis B.J. Lewis Royal Military College of Canada Royal Military College of Canada Ottawa Chapter, Canadian Nuclear Society Ottawa Chapter, Canadian Nuclear Society Ottawa, Ontario Ottawa, Ontario April 16, 2009 April 16, 2009

Aircrew and Spacecrew Radiation Exposure “The Dangers of Getting High”

Outline

Aircrew Radiation Exposure Assessment

Measurements and Computer Code Development

Space Radiation Monitoring

Typical Annual Radiation Exposure

Total Average Annual Exposure 3.6 mSv

Impetus

• ICRP-60 (1990) and ICRP-103 (2007):

– Reduce radiation exposure limits:

• Nuclear Energy Worker (NEW): 50 to 20 mSv/year
• Public: 5 to 1 mSv/year

– Recognize occupational exposure of aircrew to radiation

Aircrew Radiation Regulation

• European Union

(Basic Safety Standard Directive, May 2000)

• Canada

(Transport Canada, Commercial and Business Aviation Advisory Circular, April 2001) – Account for exposure for >1 mSv/y (> 8 km)

• Assess exposure
• Adjust working schedules (> 6 mSv action level)
• Inform workers
• Control doses during pregnancy (<1 mSv)

• P. Band et al., B.C. Cancer Foundation (Cdn/AC Pilots, 1950-1992)

– Excess AML and prostatic cancer

• J. Grayson et al., Brooks AFB (USAF Pilots, 1975-1989)

– Excess cancer in all sites, testis & urinary bladder

• E. Pukkala et al, Finnish Cancer Registry (FAs, 1967-1992)

– Excess female breast and bone cancer

• European Study of Cancer Among flying PErsonnel (ESCAPE) (9 countries) (1960-1997)

– Scarce evidence for specific occupational cancer risk – Revised interest with ESCAPE II (or COSMIC) study to include US PAN AM cohort

• D. Irvine, British Airways Pilots, 1998
• B. Grajewski, NIOSH Studies (FA (1998-2000), Pilots (2001))

– FAs reproductive health effects – Biomarker study of pilots

Epidemiological Studies

Radiation Exposure to Aircrew

Complex mixed-radiation field Galactic Cosmic Rays (GCR) Solar Particle Events (SPE)

Galactic Cosmic Ray (GCR) Exposure Conditions

• Relatively constant field dependent upon:
• Solar Activity
• Latitude
• Altitude
• Complicated field
• Many particle types, large energy range
• Greater uncertainty in biological risk

Solar Magnetic Field Shielding (When)

• GCR intensity

GCR intensity anticoincident anticoincident with solar cycle with solar cycle

50 100 150 200 250 300 350 400 1953 1958 1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 Year S u n s p o t N u m b e r 1500 2000 2500 3000 3500 4000 4500 C lim a x H o u rly C o u n t R a te /1 0 0 19 20 21 22 23

Earth Magnetic Field Shielding

(Where)

• Greater shielding at equator than

geomagnetic poles (factor of ~3)

Atmospheric Shielding (How High)

Satellite Balloon Supersonic Subsonic High Peaks

Atmospheric Nucleus 40 km 20 km 10 km 1 km

MNS LET Chamber NE213 Scintillator Anthropomorphic Phantom with TLDs and BDs BGO Scintillators

Detector NIMs, Computers, UPS

LLRM

Equipment Suite Development

Commercial Aircraft Measurement

TEPC TEPC SWENDI SWENDI Eberline Eberline NRD NRD SWENDI SWENDI Ionization Ionization Chamber Chamber

Aircrew Radiation Studies

Experimentation

• ~250 Flights (Portable Instruments)
• Ionization Counter/Al2O3 TLDs (low-LET)
• SWENDI Remmeter/Bubble Detectors (high-LET)
• Liulin-4N and 4SN (Si-based) LET Spectrometers
• Tissue Equivalent Proportional Counter (Hawk TEPC)

Model/Code Development

• Predictive Code AIrcrew Radiation Exposure (PCAIRE)

20 40 60 TEPC IC TLD SWENDI BD

TOTAL = NEUTRON IONIZING +

Ambient Dose Equivalent Distribution (μSv)

Gamma Gamma X X-

• Ray

Ray Electron Electron Ionizing Ionizing (low (low-

• LET)

LET) Neutrons Neutrons (high (high-

• LET)

LET) 20 20 1 1 1 1 1 1

Quality Factor

Aircrew

Q=1 38% Q>1 62%

US Atomic Radiation Workers Q=20 Lung 4% Q=1 93% Q>1 Other 3%

Global Flight Group Flight Time (h) Total Dose

• Eq. (μSv)

Trans-Pacific (CYVR-KIX) Trans-Atlantic (CYYZ-LHR) Trans-Canada (CYYZ-CYVR) Caribbean (BGI-CYYZ) Northwest/Yukon (CYOW-CYFB CYRB-CYSR-CYFB-CYOW) 10.2 6.5 5.0 5.7 10.2 57 ± 9 39 ± 6 35 ± 5 27 ± 4 54 ± 28 2.2 ± 0.4 2.5 ± 0.4 2.4 ± 0.4 2.2 ± 0.4 3.4 ± 0.6

TEPC Data from Selected Flight Routes

Q

Data Coverage

HNL LP PD DIAP

PGUA

TEPC Count Rate

500 1000 1500 2000 2500 0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00

Time (Z) Count Rate (C ounts/M in)

19:00 20:00 21:00 22:00 23:00 0:00 1:00 2:00

Time (Z)

5000 10000 15000 20000 25000 30000 35000 40000

Altitude (ft)

Heading North

Constant Latitude

YGK-YYZ-HGK Polar Flight (2005)

YGK-YYZ YYZ-HGK (polar) HGK HGK-YYZ YYZ-YGK

Toronto to Hong Kong Hong Kong to Toronto

4/18/05 9:00 4/18/05 21:00 4/19/05 9:00 4/19/05 21:00 4/20/05 9:00 4/20/05 21:00

Date and Time

2000 4000 6000 8000 10000 12000

Altitude (m)

IC+SWENDI HAWK FH41B LiuLin FH41B Corrected Flight Altitude 0.1 1 10

Ambient Dose Equivalent Rate (uSv/h)

TEPC Data Analysis

Geomagnetic latitude calculated from geographic latitude & longi Geomagnetic latitude calculated from geographic latitude & longitude tude

Geomagnetic Latitude, Bm (deg)

• 45
• 30
• 15

15 30 45 60 75 90

Ambient Total Dose Equivalent Rate, H (μSv/h)

2 4 6 8 10 12 14 16 9.4 km 10.0 km (+2 μSv/h) 10.6 km (+4 μSv/h) 11.2 km (+6 μSv/h) 11.8 km (+8 μSv/h) Best Fit at 10.6 km

.

Latitude Dependence: Dose Rate Vs Cutoff Rigidity

Ambient dose equivalent rate (35000 ft)

Cutoff Rigidity, Rc (GV)

2 4 6 8 10 12 14 16 18

Ambient Dose Equivalent Rate (μSv/h)

2 4 6 8 10

North South Best Fit

.

GCR ability to penetrate magnetic GCR ability to penetrate magnetic field field

Global Cutoff Rigidity Contours

Altitude Effect (Balloon Flights)

Satellite Balloon Supersonic Subsonic High Peaks

Atmospheric Nucleus 40 km 20 km 10 km 1 km

Atm

• spheric Depth h (g / cm

2)

200 400 600 800 1000

fAlt

0.01 0.1 1 10 Balloon Data (July 14, 2001) Balloon Data (July 23, 2001) M

• del

Solar Cycle Effect (10.7 km)

Vertical cutoff rigidity Rc (MV)

2 4 6 8 10 12 14 16 18

Ambient dose equivalent rate (μSv/h) normalized to 10.6 km

2 4 6 8

RMC IC+SWENDI (Climax = 3744 counts/h/100, Φ = 984 MV) ACREM IC+NMX (Climax = 4277 counts/h/100, Φ = 498 MV) Best Fit ACREM IC+NMX Best Fit RMC IC+SWENDI

Poles Equator

IC + SWENDI

PCAIRE Code

Visual_PCAIRE.exe

PCAIRE Code vs Concorde/ER-2 (NASA) (High-Altitude)

15.2 -18 km (Concorde) 15.2 - 21 km (ER-2) PCAIRE Predicted Route Dose (μSv)

20 40 60 80 100 120 140 160

TEPC Measured Route Dose (uSv)

20 40 60 80 100 120 140 160 Heliocentric Potential (FAA) Deceleration Param eter (NASA) Concorde Flights ER-2 South 1 & 2 ER-2 East ER-2 North 2 ER-2 North 1

Aircrew Annual Exposure

1 2 3 4 5 6

Flight Attendants Pilots

PC-AIRE Prediction of Annual Dose Equivalent (mSv)

ICRP 60 Public Limit

99-EHD-239

2 4 6

Average Exposure (mSv/year)

Occupation

Nuclear Fuel Handler Industrial Radiographer Uranium Miner Nuclear Medicine Technologist Commercial Aircrew

Canadian Annual Occupational Exposures

Health Impact

• ~25% of population will develop fatal cancer
• If aircrew exposed to 6 mSv/y over 30 years, risk of

developing a fatal cancer: 6 mSv/y x 30 y x 4 x10-5 cancers/mSv = 0.7%

Radiation Exposure from Solar Particle Events (SPE)

• Highly sporadic events associated with

solar flares and coronal mass ejection

– Additional exposure to aircrew

Aircrew Exposure from SPEs

• Propagate GCR and GOES-11 spectra (p, He) through

atmosphere with Monte Carlo Code (MCNPX)

Proton Flux (n/MeV/sr/cm2) Proton energy (MeV) SPE GCR

Dose and NM Count Rate Prediction

( ) ( ) ( ) ( )

∑ ∑ ∑ ∑ ∑ ∑

= Ω = = Ω + − = Ω = = Ω + −

= ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ ⎭ ⎬ ⎫ ⎩ ⎨ ⎧ ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ ⋅ ⋅ Δ ⋅ = = ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ ⎭ ⎬ ⎫ ⎩ ⎨ ⎧ ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ ⋅ ⋅ Δ ⋅ =

m i i prim E i NM m i n j prim i E ij j i i m i i prim E i A m i n j prim i E ij j i i

E Φ E P Φ h s P R E c C E Φ E P Φ P K E c H

1 , 1 1 , 1 , 1 1 , 1 1 , 1 , 1

3600 ) h count ( h s 3600 ) h Sv ( , E & & & & & & &

NM Count Rate Dose Rate Energy bin width NM Response Function MCNPX matrix coefficients Primary GOES spectrum Dose Conversion Coefficient

Global Cut-

• ff Rigidity

Contours

Noisy Sun Effects

Solar Storm Effects and Solar Flare Anisotropy

"SOHO (ESA & NASA)"

Neutron monitor peak count rate - April 15

th, 2001

1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04

100 1000 10000 Effective Cutoff Rigidity (MV)

Count Rate (C/s)

RMC Model (0 km) Thule Oulu Cape Schmidt Lomniky Stit Magadan Irkutsk Alma Ata Apatity Jungfraujoch Kiel Newark Rome Yakutsk RMC Model (3 km) South Pole

RMC Model (0 km) RMC Model (3 km)

Neutron Monitor Analysis

SPE Aircrew Exposure (GLE 60)

2 4 6 8 10 12 14 16 18 10 11 12 13 14 15 16 17 18 19 20

GCR (background) (PCAire v7.2) SPE Model Measurements (MDU)

Prague – JFK International, NY

Start of Solar Flare

Ambient Dose Rate (μSv/hr)

Universal Time (UTC) * Spurny et al

(April 2001)

Commercial Code Development: PCAIRESys

• Operational environment:

– Not for Research – Monitoring system for large number of personnel and flights

Airline Human resources database Airline Human resources database

PCAIRE PCAIRESys Sys

Dose database

• dose by flight
• dose by crew

I n t e r f a c e Pcaire system administrator Employees Employer National Dose Registry Database administrator

Sources of Space Radiation (Manned Missions in Low-Earth Orbit)*

S N SOUTH ATLANTIC ANOMALY (Protons) INNER RADIATION BELT (Protons) OUTER RADIATION BELT (Electrons) OUTER RADIATION BELT (Electrons) GALACTIC COSMIC RADIATION (GCR) (Protons to Iron Nuclei) Magnetic Axis Spin Axis * Adapted from: M. Golightly, “Radiation Familiarization,” CSA Training with SRAG, NASA, JSC, January 27-31, 2003. SOLAR PARTICLE EVENT (Protons to Iron Nuclei)

Nominal In-flight Radiation Environment

Electrons in outer radiation belt Galactic Cosmic Rays Protons in South Atlantic Anomaly

Space Weather Radiation Enhancements

Outer electron belt enhancement--electrons Solar particle event (SPE)--protons Additional radiation belts-- high energy electrons, protons (?)

Parameters that Affect Exposure or Susceptibility

• Mission Factors
• Space Weather
• Orbit Inclination
• South Atlantic Anomaly (SAA) Passage
• Altitude
• Shielding
• Length of Mission
• Individual Factors
• Sex
• Age
• Health Status
• Nutritional Status
• Ethnicity

IV-CPDS TEPC RAMs CPDs TEPC PRDs CPDs EV-CPDS

EV-CPDS: Extra- Vehicular Charged Particle Spectrometer IV-CPDS: Intra- Vehicular Charged Particle Spectrometer TEPC: Tissue Equivalent Proportional Counter RAM: Radiation Area Monitors (TLDs) PRD: Passive Radiation Dosimeter (TLDs) CPD: Crew Passive Dosimeter (TLDs, PNTD) Active instrument real-time telemetry Active instrument no real-time telemetry Passive instrument

Space Radiation Monitoring

* Adaped from: M. Golightly, “Initial Briefing to Astronauts Radiation Exposure During Space Missions, 1998 Astronaut Candidate Class,” NASA-JSC, June 10, 1999.

Space Dosimetry*

Type Program Measurements

Crew Personnel Dosimetry: TLD-100 All Programs Absorbed dose TLD-300, 600, 700 STS, and ISS Absorbed dose CR-39 or other Nuclear plastic track detectors Apollo, Skylab, STS, STS, Mir Fluence vs. LET or Z Fission Foils Apollo, STS Neutrons Area dosimetry: TLD-100 STS, Mir, ISS Absorbed dose TLD-300, 600, 700 STS, ISS Absorbed dose CR-39 or other Nuclear plastic track detectors Fluence vs. LET or Z Fission Foils Apollo, STS Neutrons Active Ionization Chambers Apollo, Skylab Absorbed dose TEPC STS, Mir, ISS Lineal energy, dose, dose equivalent Z,E Telescope Mir, STS, ISS Fluence vs. Z and E Bonner Spheres STS, ISS Neutrons Bubble detectors STS Neutrons

*Adapted from: F. Cucinotta, “Organ Dose Estimates for Astronauts,” CSA Training with SRAG, NASA-JSC, January 27-31, 2003.

Typical Exposures

• Daily Exposures

– 150 – 200 μGy/d (solar max) (2 x greater at solar minimum) – 25 mGy or ~ 60 mSv for 140 days (CNSC terrestrial limits are 20 mSv/y) – Dependent upon where you spend your time/sleep/timing/altitude etc.

• SPE Doses (IVA)

– Highly variable

• Small events ~100– 200 μGy ( ~ 300 μGy @ TEPC/Lab Fwd)
• Large events ~ 10 – 20+ mGy (Jul 2000 estimate ~6 mGy @ Node1)

Radiation Exposure Comparisons

Type of Exposure

• Limit: Annual Canadian Public
• Limit: Annual Canadian Radiation Worker
• Average annual exposure to natural background
• Average annual occupational exposure (US) (ground)
• Living one year in Kerala, India
• Airline Flight Crew
• Apollo 14 Highest Skin Dose
• Average Shuttle Skin Dose
• STS 82 Highest Skin Dose
• STS-57 (473 km, 28.5°)
• STS-60 (352 km, 57°)
• 140 day mission on ISS (400 km, 51.56°)
• 1 year in deep space (5 g cm-2 Al shielding)
• 1 year deep space (5 g cm-2 polyethylene shielding)
• Mars mission BFO Dose (GCR+SPE: behind 10 g cm-2 shielding) (3-year)

Dose Equivalent

1 mSv/y 20 mSv/y 2.94 mSv/y 2.10 mSv/y 13 mSv/y 1-6 mSv/y 14 mSv ~4.33 mSv 76.3 mSv 19.1 mSv 4 mSv ~60 mSv 1140 mSv 870 mSv 800 to 2000 mSv

Biological Effects of Ionizing Radiation

• Ionizing radiation causes atoms and molecules to become ionized or excited:

– Produce free radicals – Break chemical bonds – Produce new chemical bonds and cross-linkage between macromolecules – Damage molecules that regulate vital cell processes (e.g. DNA, RNA, proteins).

• Tissues that undergo rapid cell regeneration are most

sensitive to radiation (e.g., blood-forming organs, reproductive organs, and lymphatic system)

U.S. Astronaut Exposure Limits

Exposure Duration Blood Forming Organs Eye Skin 30 days 0.25 1.0 1.5 Annual 0.50 2.0 3.0

Career Limit: fatal cancer (3% for all ages and both sexes)

National Council on Radiation Protection and Measurements (NCRP), “Guidance on Radiation Received in Space Activities.” NCRP Report No. 98, (July 31, 1989) NCRP Report No. 132 (Dec 2000) Career Exposure Lim its NCRP Report No. 9 8 ( 1 9 8 9 ) ( Sv) 1 0 Year Career Exposure Lim its NCRP Report No. 1 3 2 ( 2 0 0 0 ) ( Sv) Age ( yr) Male Fem ale Male Fem ale 25 1.5 1.0 0.7 0.4 35 2.5 1.75 1.0 0.6 45 3.25 2.5 1.5 0.9 55 4.0 3.0 3.0 1.7

Non-Stochastic (Deterministic) Effects: NCRP-98 (Sv) and NCRP-132 (Gy-Eq)*

*NCRP-132 uses relative biological effectiveness (RBE) in place of quality factor (Q)

Observed Astronaut Health Effects (Hamm & Al 2000)

• Significant increase in lifelong risk of cataracts in astronauts
• Of 48 lens opacities in 295 astronauts, 39 of those occurred after space flight
• 90% of those 39 cataracts occurred after lunar missions and high inclination space flights
• 14 cases of cancer in 312 astronauts from 1959 to present (excluding non-

melanoma skin cancers)

• 59% higher than the control group

• No protection from

Earth’s magnetic field

image from NASA/Viking

Interplanetary Travel

Summary

Aircrew Radiation

• PCAIRE Code Development (GCR and Solar Flares)

Experimentally-based - Only one! Commercial Airline Application (spin off) (PCAIRESys)

• Space Radiation

Acknowledgements

• RMC Research Team: Prof. L. Bennett, Research Associates and Assistants

(A.R. Green, A. Butler, M. Boudreau, B. Bennett), Graduate Students (Dr. P. Tume, M. McCall, B. Ellaschuck, M. Desormeaux, Dr. M. Pierre, H. Al Anid)

• Air Canada, Canada 3000 Airlines, Canadian Airlines International, Canadian

Regional Airlines, First Air, Aerolinas Argentinas, British Airways, Air Operations at 8 Wing Trenton, 437/436/429 Squadrons

• J. Servant (Transport Canada),C. Thorp & S. Kupca (DGNS/DND), W. Friedberg

(US Federal Aviation Administration), H. Goldberg (Air Transport Association of

Canada), M. Pelliccioni & A. Zanini (INFN), E. Felsberger (U Graz), S. Roesler

(CERN), A. Chee (Boeing), H.Schraube (GSF), W. Heinrich (U Siegen), K. O’Brien (Northern Arizona U), U. Schrewe (FHH), D. Bartlett (NRPB), V. Ciancio (UNP), D. Irvine (British Airways), J. Lafortune and F. Lemay (PCAIRE Inc)

• G. Badhwar (NASA-JSC), F. Cuccinotta (NASA-JSC)
• H. Ing, M. Smith, K. Garrow (Bubble Technology Industries)