Community Environmental
Monitoring Program
Dr. Antone L. Brooks
July, 2011
Brian Head, Ut
My Background
• Early interest in radiation (Watching atomic weapons in
Southern Utah)
• MS in radiation ecology (Chasing fallout),PhD in
•
•
radiation biology and genetics
Studied health effects induced by low doses
from internally deposited radio-nuclides
Invested my life in research on genetic effects
and cancer from low doses and dose-rate
radiation (DOE Low Dose Radiation Research
Program)
Bad
Diet
Why Me??
Drinker
Radiation
Smoker
RADIATION
I am Blamed for much Human Disease
• Cancer of all kinds
• Mutations
• Birth Defects
• Heart attacks
• Stroke
I have even been blamed for !!!
Ninja Turtles
Spider Man
Incredible Hulk
I am natural, Radiation is everywhere
Cosmic
Inhaled Radon
Bodies
Plants
Radioactive Elements
Rocks
We live in a sea of radiation…
Normal annual exposure from natural radiation
About 240 mrem/yr




Radon gas
Human body
Rocks, soil
Cosmic rays
140 mrem
40 mrem
30 mrem
30 mrem
Normal annual exposure from man-made radiation
About 300 mrem/yr







Medical procedures
Consumer products
One coast to coast airplane flight
Watching color TV
Sleeping with another person
Weapons test fallout
Nuclear industry
280 mrems
10 mrems
2 mrems
1 mrem
1 mrem
less that 1 mrem
less than 1 mrem
U.S Dose Rates from Natural
Background
Nevada Test Fallout
Simon et al. 2006
World wide fallout in the United States
Cancer Rate is Highly Variable
•
Race
•
Sex
•
– White 136/100,000
– Black 294/100,000
– Males 60.6%
– Females 39.4%
Geographic Distribution No link between high Background
Radiation and Cancer
–
Areas with top 10 percentile of cancer= 231-892 cancers/100,000 person-years (low background)
–
Areas with lowest 10 percentile of cancer= 93-168 cancers/100/000 person-years (high background)
What Causes Cancer? I am not a big hitter!!!
Cigarette smoke
Diet & nutrition
Chronic infection
Occupational exposure
Genetic
Alcohol drinking
Environmental factors
including radiation
What Radiation Exposures
Can we Modify?
Man-made vs natural radiation
Fallout
2%
Occupational
Nuclear
fuel cycle
1%
2%
Consumer
products
16%
Nuclear
medicine
21%
Medical x-rays
58%
Man-made
radiation
18%
Natural
background
radiation
82%
Beir VII
What Radiation Exposures
can we Modify?
Man-made vs Natural Radiation
Occupational Fallout
1%
1%
Nuclear fuel cycle 0.5%
Consumer
products
6.5%
Nuclear medicine/x-rays
91%
Man-made
radiation
52%
Natural
background
radiation
48%
Mettler 2007
Medical Radiation Exposures,
YES, BUT I DO A LOT OF GOOD!!!
• 200 million medical x-rays/year
– X-ray 0.1 mGy
• 100 million dental x-rays/year
– Dental 0.06 mGy
• 16 million doses of radiopharmaceuticals/yr
• 80 million CT scans/year
Brenner and Hall
– Head scan 4-6 mGy/scan
AAPM TG-204, 2011
– Body scan 30-100 mGy/scan
• Large doses from radiation therapy
17
ISCORS Update Nov 2010
U.S. Department of Energy • Office of Science • Biological and Environmental Research
What about the A-Bomb!!
You did a lot of damage there.
•
•
•
•
•
Cancer
Mutations
Birth Defects
Heart attacks
Strokes
Effects
of the
Atomic Bomb
• Killed
outright by
the bomb or acute
More than
200,000 people
radiation effects.
• Survived
for
lifespan study
86,572 people
A-BOMB SURVIVOR STUDIES
5% less
cancer
than
total
controls
46,249
“Exposed”
10,159
“Controls”
Pierce and Preston 2000
A-BOMB SURVIVOR STUDIES
Preston et al. 2004
CONTROL AREA
Excess
Solid Tumors
Excess
Leukemias
113
28.2
116
99
64
27.7
18.9
41
10.4
44
4.7
2
479 Total
572 Total
Excess
Cancers
4.0
0.1
93 Total
Atomic Bomb Survivor
Excess Cancer
Population of Survivors Studied
86,572
40% of these people are still alive 60 years after the bomb
Cancer Mortality observed after the bomb
10,127
Cancers Mortality observed without the bomb
9,555
Total Cancer Mortality Excess
Excess Solid + Excess Leukemia = 572
Tumor 479
94
572
Where do we get these excess cancers??
Aggregation of data on Solid Cancers
• Total Solid Cancers 9555
• Stomach 2867
– Life Style, Diet, stomach bacteria
• Liver 1236
– Long Latency
– Influence of chronic Infections
– Alcohol
• Lung 1264
– Smoking
– Non-linear Dose-response
Preston et al. 2003
Biology of Solid Cancers
• Can we really group all Solid Cancers then apply the
LNT to estimate responses at low doses?
– Stomach Cancer
– Lung Cancer
– Liver Cancer
• All these cancers are known to be produced by environmental
factors
– Bone Cancer
– Lung Cancer
• These cancers have very non-linear Dose-Response Relationships
– Thyroid Cancer
– Prostrate, Pancreas, Uterus, Rectum???
Aggregation of Solid Cancer: Influence on
Policy
• Pay for the types of cancers seen to be elevated in the Abomb population.
– Solid Cancers
– Leukemia
• Current Pay-out Cancers for Down-Winders, Nuclear
Veterans, Uranium Miners
– Bone, renal, leukemia, lung, multiple myeloma, bile duct, brain, breast,
colon, esophagus, stomach, bladder, gal bladder, liver, ovary, pharynx,
salivary gland, small intestine, thyroid, lymphoma (five years after
exposure)
– Current payout
•
•
RECA = 1.3 Billion
EEOICA = 3.2 Billion
Interaction with Environmental
factors (I get the blame!!!)
• Smoking and Uranium mining
• Radiation and alcohol
• Radon in homes
Radon in Homes (BEIR VI)
• Total Cancers
157,000
Ever-Smokers Never Smokers
146,400
11,000
Radon induced Cancer
Total Cancers Ever-Smokers Never Smokers
(Exposure-age-Concentration model)
22,300
20,600
(Radiation only)
1,700
(Exposure-age-Duration model)
15,500
14,600
1,200
What about when you get
deposited in the body??
• Inhalation and lung cancer
• Low dose rate and non-uniform distribution
• Deposition in target organs
–
–
–
–
Strontium-90 Bone
Iodine -131 Thyroid Cancer
Cesium-137 Whole Body Exposure
Tritium Whole Body Exposure
Dose Dose-Rate Effectiveness
(DDREF) Factor is it 1.0?
• Dose-Dose-Rate-Effectiveness-Factor (DDREF),
regulatory bodies considering making it (1.0)
• Dose-rate has a marked effect at all levels of biological
orgainztion
• All you have to do to make DDREF 1.0 is accept a
couple of low dose-rate epidemiological studies which
cannot demonstrate a difference in risk for high and low
dose rates
• All you have to do to make a DDREF of 1.0 is to ignore
70 years of radiation biology
Dose-Rate Effects at all Levels of Biological
Organization
• Molecular
• Cellular
• Tissue
• Whole Organ
• Cancer
• Life Shortening
Dose and Dose-Rate Effects
DDREF derived with curve fitting of the human data.
•
•
•
DDREF 1.5 BEIR VII
DDREF 2.0 ICRP (2007)
DDREF 1.0 Considered by Germans
DREF derived from animal and experimental data.
•
•
•
•
•
Experimental Molecular/Cellular
Chromosome Aberrations
Mouse data
– Lung Adenocarcinomas
– Ovarian Tumors
– Thymic lymphoma
– Mammary tumors
– Myeloid Leukemia
4-???
4-6
3-7
7-35
10-30
1-4
2-6
Dog Data
– (Acute Death Bone Marrow)
– (Acute Death Lung)
Dog Data (Cancer)
3-4
10-100
15-40
Summary DDREF
•
•
•
A large dose-rate effectiveness factor is required due to the marked
decrease in biological effects observed following low dose-rate radiation
exposure.
Current
that
theto mechanisms
At radiation
doses research
less than 20suggests
Gy (20,000
mGy)
the lung following
inhalation
of
radioactive
materials,
there
is little
lifedelivered
shortening and
a
of
action
of
these
very
large
doses
at
decrease in the frequency of lung cancer.
low dose-rates are different to those after acute
When the dose delivered at a low
dose-rate
gets very, very large (80-220
low
doses.
Gy in Bone and 100-700 Gy in lung), the cancer frequency approaches
100%.
•
•
•
Should we consider
separating DDREF from
Genetic background plays an important role in the response to large total
radiation doses delivered at a low dose-rate.
DREF?
Such data should be considered in decisions about evacuation (10-50 mSv
At low dose-rates the total dose required to produce acute radiation
lethality is similar to the dose required to produce a high cancer frequency.
projected dose) and relocation (20 mSv projected dose first year) of the
public following radiation accidents or terrorist events.
Cancer in Beagle Dogs following Acute
Radiation Exposure
40
% Incidence
35
30
25
20
15
10
5
0
0
800 mGy
Benjamin et al 1998
Dose Response for Life Shortening Following Inhalation of
90-Strontium Fused Clay Particles
7000
6000
Days to Death
5000
Cancer
Other
4000
Heart Cancer
Lung Cancer
3000
2000
TBLN Cancer
1000
Acute
0
0
100
200
300 400 500 600 700
Cumulative Dose (Gy)
800
900 1000
All cancers
Control dogs
Control dogs
Lung cancer
Total Cancer and
Lung Cancer
75
70
Percent of Dogs with Cancer
65
60
55
50
45
40
35
30
25
20
15
10
5
0 0
5
10
15
Total dose to lung (Gy)
20
25
% Total Cancer (Controls) by Location
100
90
80
70
60
% Cancer
50
40
38.3
46.4
47.3
47.6
32.6
38.2
27.0
30
20
10
0
National Lab
% Cancer
STDEV
% Lung Cancer (Control) by Location
10
9
8
7.2
7
6
% Cancer
4.9
5
4
% L. Cancer/Dogs
3.3
2.9
3
2
1
2.0
1.6
1.0
0
National Lab
The Shape of the Dose-Response is Dependent on Control Selection
(What is the Best Control?)
ITRI FAP Controls 53
% Lung Cancer
15
10
ITRI FAP Controls
ITRI and PNNL Controls 318
ITRI and PNNL Controls
All Controls
5
ITRI Exposed
All Controls 1096
0
0.00
5.00
10.00
15.00
Total Dose to Lung (Gy)
20.00
25.00
Selection of Proper Controls??
• Dog Data
– Add more control dogs for greater accuracy
– Adding dogs greater genetic variation
– Adding dogs different environmental and life styles
• Human Data
– Match controls for life-style, stress and environment, Age, Sex
etc.
– “the distal group has about 5% higher cancer rates than
estimated for zero dose from the proximal group.” (Pierce and
Preston 2000)
– Adding more people increases variation in genetic variation,
record keeping, environment, life-style.
How much is a Bq?
• Scientific definition
• Social definition
• Risk
• Will I be OK?
Comparing Environmental and
Health Effects (Bq?)
• The levels in the environment are very nonuniform
• The amount of radiation required to produce
health effects is much higher than that in the
environment (large safety factor)
• There is a decrease in effectiveness with partial
body exposures
• There is a decrease in effectiveness with
decreasing dose-rate.
Mechanistic Studies of Low Dose Effects
•
•
•
•
•
•
•
The risk for radiation induced cancer in human populations is low and
undetectable at low doses and dose-rates thus mechanistic studies are required.
DOE Low Dose Radiation Research Program http://www.lowdose.energy.gov
Cells can detect and respond to very low doses of ionizing radiation
Radiation responses at all levels of biological organization are different at high
doses than at low doses.
High dose-rate produces more biological damage than low dose-rate exposures
Bystander effects, adaptive responses, ROS status of the cells, and genomic
instability are interrelated and can be related to protective mechanisms. This
resulted in major paradigm shifts in Radiation biology.
Thus, mechanisms of radiation action change as a function of dose and dose-rate.
Data suggest that radiation exposures are detrimental at high doses and protective
at low doses.
Mechanistic studies of Low Dose Effects
•
•
•
•
•
•
•
Cells can detect and respond to very low doses of ionizing radiation
Radiation responses at all levels of biological organization are different at high doses than at low
doses
Thus, mechanisms of radiation action change as a function of dose. Data suggest that they are
detrimental at high doses and protective at low doses.
Low Dose research require paradigm shifts in radiation biology to support the data.
Bystander effects, adaptive responses, ROS status of the cells, and genomic instability are
interrelated and can be related to protective mechanisms.
The risk for radiation induced cancer in human populations is low and undetectable at low doses
and dose-rates.
Linear low dose (LNT) extrapolation is not supported by low dose radiation research
Helpful Reviews of Health Effects from Low
dose and dose-rate radiation
• Health Physics 97: November 2009, Special Issue: 44th Annual Meeting of
the National Council on Radiation Protection and Measurements: Low
Dose and Low Dose-Rate Radiation Effects and Models.
• Dauer, LT, Brooks, AL, Hoel, D, Morgan W, Stram D, Tran P. (2010)
Evaluation of updated research on the health effects associated with lowdose ionizing radiation, Radiation Protection Dosimetry 140 (2) 103-136.
• Health Physics 100:, March 2011, Special Issue: Proceedings of the
Conference on Biological Consequences and Health Risks of Low-Level
Exposure to Ionizing Radiation: In honor of Victor P. Bond.
Radiation Risk: What Is the Public
Perception?
• Radiation is very bad
• There is good and bad radiation, (Medical and
Environmental)
• Each and every ionization increases their risk for
cancer (LNT)
• Many conclude that if you are exposed to radiation
you are going to get cancer
• If you were exposed to radiation and you get
cancer the radiation caused the cancer
It is not all my Fault!!
At low doses I do way more good than harm!!!