Aircrew and Spacecrew Radiation Exposure

Aircrew and Spacecrew Radiation Exposure
“The Dangers of Getting High”
B.J. Lewis
Royal Military College of Canada
Ottawa Chapter, Canadian Nuclear Society
Ottawa, Ontario
April 16, 2009
Outline
z Aircrew Radiation Exposure Assessment
z
Measurements and Computer Code Development
z 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)
Epidemiological Studies
•
P. Band et al., B.C. Cancer Foundation (Cdn/AC Pilots, 1950-1992)
–
•
J. Grayson et al., Brooks AFB (USAF Pilots, 1975-1989)
–
•
Excess female breast and bone cancer
European Study of Cancer Among flying PErsonnel (ESCAPE) (9 countries) (1960-1997)
–
–
•
•
Excess cancer in all sites, testis & urinary bladder
E. Pukkala et al, Finnish Cancer Registry (FAs, 1967-1992)
–
•
Excess AML and prostatic cancer
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
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 anticoincident with solar cycle
4500
400
4000
300
3500
250
3000
200
150
2500
100
50
0
1953
2000
19
1958
20
1963
1968
21
1973
1978
1983
Year
23
22
1988
1993
1998
2003
1500
2008
C lim a x H o u rly C o u n t R a t e /1 0 0
350
Su n sp o t N u m b er
•
Earth Magnetic Field Shielding
(Where)
•
Greater shielding at equator than
geomagnetic poles (factor of ~3)
Atmospheric Shielding
(How High)
Satellite
40 km
Balloon
20 km
10 km
1 km
Supersonic
Subsonic
High Peaks
Atmospheric
Nucleus
Equipment Suite Development
Detector NIMs, Computers, UPS
Anthropomorphic Phantom
with TLDs and BDs
MNS
BGO
Scintillators
LET Chamber
NE213 Scintillator
LLRM
Commercial Aircraft Measurement
Eberline
NRD
SWENDI Ionization
Chamber
TEPC
SWENDI
Aircrew Radiation Studies
ƒ 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)
ƒ Model/Code Development
• Predictive Code AIrcrew Radiation Exposure (PCAIRE)
Ambient Dose Equivalent Distribution (μSv)
60
40
20
0
TEPC
TOTAL =
IC
TLD
IONIZING
SWENDI
+
BD
NEUTRON
Quality Factor
Q=20
Lung
4%
Ionizing
(low-LET)
Q>1
Other
3%
Q=1
93%
Neutrons
US Atomic
(high
-LET)Radiation Workers
Q>1
Gamma
62%
Q=1
1
38%
X-Ray
1
Electron
1
Aircrew
20
TEPC Data from Selected Flight Routes
Global Flight Group
Trans-Pacific (CYVR-KIX)
Trans-Atlantic (CYYZ-LHR)
Trans-Canada (CYYZ-CYVR)
Caribbean (BGI-CYYZ)
Northwest/Yukon (CYOW-CYFB
CYRB-CYSR-CYFB-CYOW)
Flight
Time (h)
Total Dose
Eq. (μSv)
Q
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
Data Coverage
LP PD
DIAP
HNL
PGUA
TEPC Count Rate
40000
35000
2000
30000
25000
1500
20000
Constant Latitude
1000
15000
10000
500
Heading North
5000
0
0
0:00
1:00
2:00
3:00
4:00
Time (Z)
5:00
6:00
7:00
19:00
20:00
21:00
22:00
23:00
Time (Z)
0:00
1:00
2:00
Altitude (ft)
C o u n t R a te (C o u n ts/M in )
2500
YGK-YYZ-HGK Polar Flight (2005)
Toronto to Hong Kong
Hong Kong to Toronto
12000
IC+SWENDI
HAWK
FH41B
LiuLin
FH41B Corrected
Flight Altitude
10000
8000
1
6000
4000
2000
0.1
0
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
YGK-YYZ YYZ-HGK (polar)
HGK
HGK-YYZ
YYZ-YGK
Altitude (m)
Ambient Dose Equivalent Rate (uSv/h)
10
TEPC Data Analysis
.
Ambient Total Dose Equivalent Rate, H (μSv/h)
Geomagnetic latitude calculated from geographic latitude & longitude
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
14
12
10
8
6
4
2
0
-45
-30
-15
0
15
30
45
Geomagnetic Latitude, Bm (deg)
60
75
90
Latitude Dependence:
Dose Rate Vs Cutoff Rigidity
GCR ability to penetrate magnetic
field
Ambient Dose Equivalent Rate (μSv/h)
Ambient dose equivalent rate (35000 ft)
10
North
South
Best Fit
8
6
Global
Cutoff
Rigidity
Contours
.
4
2
0
0
2
4
6
8
10
12
14
Cutoff Rigidity, Rc (GV)
16
18
Altitude Effect (Balloon Flights)
40 km
10
Balloon
10 km
Supersonic
Atmospheric
Nucleus
1
fAlt
20 km
Balloon Data (July 14, 2001)
Balloon Data (July 23, 2001)
Model
Satellite
Subsonic
0.1
1 km
High Peaks
0.01
0
200
400
600
800
Atmospheric Depth h (g / cm2)
1000
Solar Cycle Effect (10.7 km)
Ambient dose equivalent rate (μSv/h)
normalized to 10.6 km
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
6
4
2
IC + SWENDI
0
0
2
4
6
8
10
12
14
16
18
Vertical cutoff rigidity Rc (MV)
Poles
Equator
PCAIRE Code
Visual_PCAIRE.exe
PCAIRE Code vs Concorde/ER-2 (NASA)
(High-Altitude)
TEPC Measured Route Dose (uSv)
160
Heliocentric Potential (FAA)
Deceleration Parameter (NASA)
140
120
ER-2 North 1
ER-2 North 2
100
ER-2 East
80
60
ER-2 South 1 & 2
40
15.2 -18 km (Concorde)
15.2 - 21 km (ER-2)
Concorde Flights
20
0
0
20
40
60
80
100
120
PCAIRE Predicted Route Dose (μSv)
140
160
Aircrew Annual Exposure
PC-AIRE Prediction of Annual
Dose Equivalent (mSv)
6
5
4
3
2
ICRP 60 Public Limit
1
0
Flight Attendants
Pilots
Canadian Annual Occupational Exposures
99-EHD-239
A verage Exposure
(m Sv/year)
6
Nuclear Fuel
Handler
Industrial
Radiographer
Uranium Miner
4
Nuclear Medicine
Technologist
Commercial
Aircrew
2
0
Occupation
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
Proton Flux (n/MeV/sr/cm2)
• Propagate GCR and GOES-11 spectra (p, He) through
atmosphere with Monte Carlo Code (MCNPX)
SPE
GCR
Proton energy (MeV)
Dose and NM Count Rate Prediction
Dose Conversion
Coefficient
Dose Rate
Primary GOES
spectrum
m
n
m
&E, H& (Sv h −1 ) = ∑ ⎡⎢∑ ⎧⎨c ⋅ ΔE ⋅ K ⋅ P ⋅ ⎛⎜ 3600 s ⎞⎟⎫⎬Φ& prim ⎤⎥ = ∑ P (E )Φ& prim (E )
i ,i +1
j
ij
E ,Ω i
i
A
i
E ,Ω
⎝ h ⎠⎭
i =1 ⎣ j =1 ⎩
⎦ i =1
m ⎡ n
⎧
⎛ 3600s ⎞⎫ & prim ⎤ m
prim
−1
&
C (count h ) = ∑ ⎢∑ ⎨c ⋅ ΔEi ,i +1 ⋅ R j ⋅ Pij ⋅ ⎜
⎟⎬ΦE ,Ω i ⎥ = ∑ PNM (Ei )Φ& E ,Ω (Ei )
⎝ h ⎠⎭
i =1 ⎣ j =1 ⎩
⎦ i =1
NM Count Rate
Energy bin width
MCNPX matrix coefficients
NM Response Function
Noisy Sun Effects
Global Cutoff Rigidity
Contours
Solar Storm Effects and Solar Flare Anisotropy
"SOHO (ESA & NASA)"
Neutron Monitor Analysis
th
Neutron monitor peak count rate - April 15 , 2001
1.E+04
RMC Model (3 km)
Count Rate (C/s)
1.E+03
1.E+02
1.E+01
RMC Model (0 km)
1.E+00
100
1000
10000
1.E-01
Effective Cutoff Rigidity (MV)
RMC Model (0 km)
Cape Schmidt
Irkutsk
Jungfraujoch
Rome
South Pole
Thule
Lomniky Stit
Alma Ata
Kiel
Yakutsk
Oulu
Magadan
Apatity
Newark
RMC Model (3 km)
SPE Aircrew Exposure (GLE 60)
Prague – JFK International, NY
18
(April 2001)
Ambient Dose Rate (μSv/hr)
16
14
Start of Solar Flare
SPE Model
12
Measurements (MDU)
10
8
6
4
GCR (background)
(PCAire v7.2)
2
0
10
11
12
13
14
15
16
Universal Time (UTC)
17
18
19
20
* Spurny et al
Commercial Code Development: PCAIRESys
•
Operational environment:
– Not for Research
– Monitoring system for large number of personnel and flights
Airline
Airline
Human
Human
resources
resources
database
database
I
n
t
e
r
f
a
c
e
Database
administrator
PCAIRESys
Pcaire
system
administrator
National Dose Registry
Dose database
•dose by flight
•dose by crew
Employer
Employees
Sources of Space Radiation
(Manned Missions in Low-Earth Orbit)*
INNER RADIATION BELT
(Protons)
SOLAR PARTICLE EVENT
(Protons to Iron Nuclei)
OUTER RADIATION BELT
(Electrons)
N
OUTER RADIATION BELT
(Electrons)
S
GALACTIC COSMIC RADIATION (GCR)
(Protons to Iron Nuclei)
Magnetic
Axis
Spin
Axis
SOUTH ATLANTIC ANOMALY
(Protons)
* Adapted from: M. Golightly, “Radiation Familiarization,” CSA Training with SRAG, NASA, JSC, January 27-31, 2003.
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
Space Radiation Monitoring
EV-CPDS: ExtraVehicular Charged
Particle Spectrometer
EV-CPDS
TEPC
PRDs
CPDs
IV-CPDS: IntraVehicular 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
IV-CPDS
TEPC
RAMs
CPDs
* 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
TLD-300, 600, 700
CR-39 or other Nuclear plastic
track detectors
Fission Foils
All Programs
STS, and ISS
Apollo, Skylab, STS, STS,
Mir
Apollo, STS
Absorbed dose
Absorbed dose
STS, Mir, ISS
STS, ISS
Absorbed dose
Absorbed dose
Apollo, STS
Apollo, Skylab
STS, Mir, ISS
Mir, STS, ISS
STS, ISS
STS
Fluence vs. LET or Z
Neutrons
Absorbed dose
Lineal energy, dose, dose equivalent
Fluence vs. Z and E
Neutrons
Neutrons
Area dosimetry:
TLD-100
TLD-300, 600, 700
CR-39 or other Nuclear plastic
track detectors
Fission Foils
Active Ionization Chambers
TEPC
Z,E Telescope
Bonner Spheres
Bubble detectors
Fluence vs. LET or Z
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
Dose Equivalent
•
•
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
2.94 mSv/y
2.10 mSv/y
13 mSv/y
•
Airline Flight Crew
1-6 mSv/y
•
•
•
•
•
•
•
•
•
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)
1 mSv/y
20 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
Non-Stochastic (Deterministic) Effects: NCRP-98 (Sv) and NCRP-132 (Gy-Eq)*
Exposure
Duration
Blood Forming
Organs
Eye
Skin
30 days
0.25
1.0
1.5
Annual
0.50
2.0
3.0
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)
*NCRP-132 uses relative biological effectiveness (RBE) in place of quality factor (Q)
Career Limit: fatal cancer (3% for all ages and both sexes)
Career Exposure Limits
NCRP Report No. 98 (1989)
(Sv)
10 Year Career Exposure Limits
NCRP Report No. 132 (2000)
(Sv)
Age (yr)
Male
Female
Male
Female
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
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 nonmelanoma skin cancers)
•
59% higher than the control group
Interplanetary Travel
• No protection from
Earth’s magnetic field
image from NASA/Viking
Summary
z
Aircrew Radiation
z
PCAIRE Code Development (GCR and Solar Flares)
z
z
Experimentally-based - Only one!
Commercial Airline Application (spin off) (PCAIRESys)
• Space Radiation
Acknowledgements
ƒ 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)
ƒ 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
ƒ 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)
ƒ G. Badhwar (NASA-JSC), F. Cuccinotta (NASA-JSC)
ƒ H. Ing, M. Smith, K. Garrow (Bubble Technology Industries)