From X-rays to Cordless Phones:
Radiation Causes Brain Tumors
Lloyd Morgan
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Ionizing Radiation
Exposures are from X-rays, A-bombs, radioactivityOnly “known” environmental cause of brain tumors (since 1974 or earlier)Energy sufficient to break molecular bonds
For example, DNA• Broken DNA creates free radicals
– Free radicals cause further DNA damage thought to cause cancer
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Ionizing RadiationIncreased risk of brain tumors
Age: Children at greater risk than adultsDose measured in Gray (Gy): Risk increases linearly with dose
• Dose=(Radiation power)/(weight of exposed tissue) x (time)
– Risk increases with power (Watts)– Risk increases with time
Excess risk, 30 or more years (all ages) [1]Brain Cancer: 200+%Meningioma: 70+%
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Risk by Age, Brain Cancer:Children “cured” of ringworm of the scalp by X-rays [1]
Excess Relative Risk (ERR) per Gray (Gy) for Malignant Brain Tumorsby Age at Exposure
from Ionizing Radiation Exposure
0%
50%
100%
150%
200%
250%
300%
350%
400%
<5 5-9 10+
Age at Exposure
ERR/GY
Mean estimated dose: 1.5 Gy (range 1.0 to 6.0 Gy)
Source: Sadetzki et al., Long-Term Follow-up for Brain Tumor Development after ChildhoodExposure to Ionizing Radiation for Tinea Capitis; RADIATION RESEARCH 163, 424–432 (2005)
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Excess Risk Increases Every Year From Exposure [1]
Excess Absolute Risk for Malignant Brain Tumorand Non-malignant Meningioma
from Exposure to Ionizing Radiation
14%
37%
74%
55%
203%
18%
0%
50%
100%
150%
200%
250%
<20 20-29 30+
ExcessAbsolute
Risk
Malignant
Meningioma
Years from Exposure to Diagnosis (Latency Time)
Source: Sadetzki et al., Long-Term Follow-up for Brain Tumor Development after ChildhoodExposure to Ionizing Radiation for Tinea Capitis; RADIATION RESEARCH 163, 424–432 (2005)
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Ionizing Radiation
Latency time (from exposure to diagnosis)
Brain Cancer: 20 to 30 yearsMeningioma: 30-40 years
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Small percentage of total tumors seen at 20 years [1]
40 Years After Exposure: Cumulative % of Malignant Brain Tumorsfrom Ionizing Radiation by Years to Diagnosis (Latency Time)
100%
45.2%
25.8%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
<20 <20-29 20-40
Latency Time for Tumor Diagnosis (Years)
Mean Age at Exposure: 7.1 years (range <1 to 15 years)
Source: Sadetzki et al., Long-Term Follow-up for Brain Tumor Development after ChildhoodExposure to Ionizing Radiation for Tinea Capitis; RADIATION RESEARCH 163, 424–432 (2005)
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Non-ionizing Radiation: Wireless Phones
Exposures from cellphones, cordless phones, walkie-talkies, baby monitorsRisk of brain tumorsEnergy cannot break molecular bondsCreates free radicals; increases lifetime of free radicals
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Non-ionizing Radiation: Wireless PhonesIncreased risk of brain tumors
Age: Younger have higher risk [2]• Greater than 5 years of cellphone use
– 700+% for 20-29 years olds (7 cases, 94.8% confidence)– 35% for all ages, 20-80 years (160 cases, 97% confidence)
Dose measured in Gray (Gy)• Dose=(Radiation power)/(weight of exposed tissue) x
(time)– Risk increases with power (Watts)– Risk increases with time
Tumor on same side of head as where digital cellphone was used [5]
• 260+% increased risk of brain cancer (97 cases, 99.91% confidence)
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Wireless Phones: Risk by Age [2]
Increased Risk of Brain Tumor
0%
100%
200%
300%
400%
500%
600%
700%
800%
20-80 years 20-29 years 20-80 years 20-29 years
Analog cellphone Cordless phone
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Non-ionizing Radiation: Wireless PhonesIncreased risk of brain tumors
Power: Increase risk with higher wattage (phone type or distance from cell tower)
• Rural cellphone users have 740% higher risk of brain cancer than urban users after 5 years of digital cellphone use (10 cases, 95.6% confidence) [3]
Time: Ten years after first use, increased risk of brain cancer with greater hours of use [5]
• Cordless phone use (median hours of use=243 hours)
– 30% increased risk for less than median hours of use (5 cases, 35% confidence)
– 310% increased risk for more than median hours of use (25 cases, 99.996% confidence)
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Non-ionizing Radiation: Digital CellphonesLatency time
Much shorter latency time than ionizing radiation (1st tumor after X-ray for ringworm was 7 years)
• Brain cancer [5]– 60% increased risk, 1 to 5 years of digital
cellphone use– 100 cases, 98% confidence
– 120% increased risk, 5 to 10 years– 79 cases, 99.96% confidence
– 260% increased risk, more than 10 years– 19 cases, 99.94% confidence
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Non-ionizing Radiation: Analog Cellphones
Acoustic Neuroma [4]• 230% increased risk, 1 to 5 years of
cellphone use– 16 cases, 99.3% confidence
• 340% increased risk, >5 to 10 years– 33 cases, 99.99996% confidence
• 310% increased risk, >10 years– 19 cases, 99.98% confidence
• 380% increased risk, >15 years– 6 cases, 99.3% confidence
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Non-ionizing Radiation: Analog Cellphones
Meningioma [4]• 20% increased risk, 1-5 years of
cellphone use– 32 cases, 63% confidence
• 20% increased risk, 5 to 10 years– 47 cases, 63% confidence
• 60% increased risk, more than 10 years– 34 cases, 96% confidence
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Wireless Phones:Years of Exposure [4, 5]Increased Risk of Brain Tumor by Year of
Wireless Phone Use
0%50%
100%150%200%250%300%
Bra
inC
ance
r
Bra
inC
ance
r
Bra
inC
ance
r
Men
ingi
oma
Men
ingi
oma
Men
ingi
oma
Aco
ustic
Neu
rom
a
Aco
ustic
Neu
rom
a
Aco
ustic
Neu
rom
a
Anaog Digital Cordless Anaog Digital Cordless Anaog Digital Cordless
Wireless Phone Type
Increasedrisk 1 to 5 years >5 to 10 years >10 years >15 years
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Cellphone Industry’s Studies of the Risk of Brain Tumor from Cellphone Use
“Interphone” studies rarely find a risk of brain tumors from cellphone use
13 participating countries• Increased risk has been found
– 4 of 7 studies found increased risk for more than 10 years of use [7, 8, 10, 12]
Major funding received from cellphone industry• Funding “was governed by agreements that
guaranteed complete scientific independence”– The researchers knew where the funding had come from
– “Don’t bite the hand that feeds you,” is the psychological reality
– Doesn’t mean that the researchers are dishonest
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Scatter Plots (following slides)Vertical axis is percentage confidence of a findingHorizontal axis is excess (or decrease) risk of a brain tumor of a findingRisk overview
If no risk• About half of all findings will show increased risk
and• About half of all findings will show decreased risk
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Scatter Plots (following slides)Scatter plot: regions of importance
Line of "Statistical Significance“• Indicates 95% confidence
– When confidence is 95% or more, it is said to be “statistically significant” (pale yellow region)
Area of Little to No Statistical Meaning (reddish region)• Zero percent confidence to 90% confidence
Area of Marginal Statistical Meaning (orange region)• 90% to 95% confidence
Region where study bias may explain increased/decreased risk (bright yellow region)
• Increase risk and decreased risk between up to 100%– Epidemiologists’ rule of thumb where bias or confounding
problems may explain a finding
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Industry studies compared to independent studies [5, 9, 11]
Excess Risk of Glioma with 5 Years or More and/or Cellphone Use on Same Side of Head as Tumor Location Combinations of Wireless Phone Use: Results from
Hardell et al. and Interphone Studies
0.0000001
0.0000010
0.0000100
0.0001000
0.0010000
0.0100000
0.1000000
1.0000000
-700% -600% -500% -400% -300% -200% -100% 0% 100% 200% 300% 400% 500% 600% 700%
p-value(% Confidence)
Line of "Statistical Significance"
(99.999%)
(99%)
(99.9999%)
(99.99999%)
(99.99%)
(99.9%)
(90%)
Increasing Risk of Glioma From Cellphone UseDecreasing Risk of Glioma From Cellphone Use
Substantial Cellphone Industry Funding of Study
Study Funding Independent of Cellphone Industry
Increased Risk of Glioma Relative to Non-Cellphone UsersDecreased Risk of Glioma Relative to Non-Cellphone Users
Region where study bias may explain increased/decreased risk
Area of Little to No Statistical Meaning
Area of Marginal Statistical Meaning
120% increased risk, 94% confidence
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Industry studies compared to independent studies [4, 8, 6, 7]
Excess Risk of Acoustic Neuroma with with 5 Years or More and/or Wireless Phone Use on Same Side of Head as Tumor Location or Combinations of Wireless Phone
Use:Results from Hardell et al. and Interphone Studies
1.000000E-08
1.000000E-07
1.000000E-06
1.000000E-05
1.000000E-04
1.000000E-03
1.000000E-02
1.000000E-01
1.000000E+00
-400% -350% -300% -250% -200% -150% -100% -50% 0% 50% 100% 150% 200% 250% 300% 350% 400%
p-value (% confidence)
(90%)
(99%)
(99.9%)
(99.99%)
(99.999%)
Line of "Statistical Significance"
Substantial Cellphone Industry Funding of Study
Study Funding Independent of Cellphone Industry
Decreased Risk of Acoustic Neuroma Relative to Non-Cellphone Users
Decreasing Risk of Acoustic Neuroma From Cellphone UseIncreased Risk of Acoustic Neuroma Relative to Non-Cellphone Users
Increasing Risk of Acoustic Neuroma From Cellphone Use
Region where study bias may explain increased/decreased risk
Area of Little to No Statistical Meaning
Area of Marginal Statistical Meaning
(99.9999%)
(99.999999%)
(99.99999%)
Strong "protective" effect
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Industry studies compared to independent studies [4, 6, 7]
Excess Risk of Meningioma with 5 Years or More and/or Cellphone Use on Same Side of Head as Tumor Location or Combinations of
Wireless Phone Use:Results from Hardell et al. and Interphone Studies
0.00100
0.01000
0.10000
1.00000
-250% -200% -150% -100% -50% 0% 50% 100% 150% 200% 250%
p-value(% confidence)
(90%)
(99%)
(99.9%)
Substantial Cellphone Industry Funding of Study
Study Funding Independent of Cellphone IndustryRegion where study bias may explain increased/decreased risk
Increased Risk of Meningioma Relative to Non-Cellphone UsersDecreased Risk of Meningioma Relative to Non-Cellphone
Decreasing Risk of Meningioma From Cellphone Use Increasing Risk of Meningioma From Cellphone Use
Area of Little to No Statistical Meaning
Area of Marginal Statistical Meaning
Line of "Statistical Significance"
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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A SpeculationWhat is the nexus between ionizing radiation and non-ionizing radiation and tumors?
Many physicists argue that non-ionizing radiation cannot cause tumors because non-ionizing radiation cannot break the molecular bonds of DNA. It is true that non-ionizing radiation cannot break DNA bonds. But the paradigm posited by many physicists assumes that only the breaking of DNA bonds can cause tumors.
Both ionizing radiation and non-ionizing radiation creates free radicals.
Perhaps the nexus is the creation of free radicals?
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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SummationIonizing Radiation
Young at greater riskLatency time
• Brain cancer, 20-30 years
– Increased risk 55%
• Meningioma, 30-40 yrs
– Increased risk 37%
Power• Increasing risk with
increasing power
Dose measure in Gray
Non-ionizing RadiationYoung at greater riskLatency time
• Brain cancer, 1-5/> 10 years
– Increased risk 60%/260%
• Meningioma, >10 years– 60%
Power• Increasing risk with
increasing power
Dose measure in Gray
Conclusion: A Query
Is the non-ionizing radiation exposure from wireless phone use a greater risk for brain tumors than ionizing radiation?
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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References
1. Sadetzki et al. Long-Term Follow-up for Brain Tumor Development after Childhood Exposure to Ionizing Radiation for Tinea Capitis; RADIATION RESEARCH 163, 424–432 (2005)
2. Hardell et al., Cellular and Cordless Telephone Use and the Association with Brain Tumors in Different Age Groups; Arch Environ Health. 2004 Mar;59(3):132-7
3. Hardell et al, Use of cellular telephones and brain tumour risk in urbanand rural areas; Occup Environ Med 2005;62:390–394.
4. Hardell et al., Pooled analysis of two case-control studies on the use of cellular and cordless telephones and the risk of benign brain tumours diagnosed during 1997-2003; INTERNATIONAL JOURNAL OF ONCOLOGY 28: 509-518, 2006
5. Hardell et al., Case–control study of the association between the use of cellular and cordless telephones and malignant brain tumors diagnosed during 2000–2003; Environ Res. 2006 Feb;100(2):232-41
Revised 22 March 2006 Lloyd Morgan email: [email protected]
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Interphone Study References
6. Christensen et al., Cellular Telephone Use and Risk of Acoustic Neuroma; Am J Epidemiol 2004;159:277–283
7. Lönn et al., Mobile Phone Use and the Risk of Acoustic Neuroma; Epidemiology Volume 15, Number 6, November 2004: 653-659 *
8. Schoemaker et al., Mobile phone use and risk of acoustic neuroma: results of the Interphone case–control study in five North European countries; British Journal of Cancer (2005), 1 –7 *
9. Christensen et al., Cellular telephones and risk for brain tumors, A population-based, incident case-control study; NEUROLOGY 2005;64:1189–1195
10. Hepworth et al., Mobile phone use and risk of glioma in adults: case-control study; BMJ. 2006 Jan 20 *
11. Lönn et al., Long-Term Mobile Phone Use and Brain Tumor Risk; Am J Epidemiol 2005;161:526–535 *
12. Schüz et al., Cellular Phones, Cordless Phones, and the Risks of Glioma and Meningioma (Interphone Study Group, Germany); Am J Epidemiol. 2006 Mar 15;163(6):512-20 *
* Study found increased risk of brain tumor