Transcript Project Organization

From X-rays to Cordless Phones:
Radiation Causes Brain
Tumors
Lloyd Morgan
Ionizing Radiation
Exposures are from X-rays, A-bombs,
radioactivity
Only “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]
2
Ionizing Radiation
Increased risk of brain tumors
Age: Children at greater risk than adults
Dose 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]
3
Risk by Age, Brain Cancer:
Children “cured” of ringworm of the scalp by X-rays [1]
ERR/GY
400%
Excess Relative Risk (ERR) per Gray (Gy) for Malignant Brain Tumors
by Age at Exposure
from Ionizing Radiation Exposure
Source: 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)
350%
Mean estimated dose: 1.5 Gy (range 1.0 to 6.0 Gy)
300%
250%
200%
150%
100%
50%
0%
<5
5-9
10+
Age at Exposure
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
4
Excess Risk Increases Every Year From Exposure [1]
Excess Absolute Risk for Malignant Brain Tumor
and Non-malignant Meningioma
from Exposure to Ionizing Radiation
Excess
Absolute
Risk
250%
Malignant
Meningioma
203%
200%
Source: 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)
150%
100%
74%
55%
50%
37%
18%
14%
0%
<20
20-29
30+
Years from Exposure to Diagnosis (Latency Time)
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
5
Ionizing Radiation
Latency time (from exposure to
diagnosis)
Brain Cancer: 20 to 30 years
Meningioma: 30-40 years
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
6
Small percentage of total tumors seen at 20 years [1]
40 Years After Exposure: Cumulative % of Malignant Brain Tumors
from Ionizing Radiation by Years to Diagnosis (Latency Time)
100%
Source: 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)
100%
90%
Mean Age at Exposure: 7.1 years (range <1 to 15 years)
80%
70%
60%
50%
40%
45.2%
30%
20%
25.8%
10%
0%
<20
<20-29
20-40
Latency Time for Tumor Diagnosis (Years)
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
7
Non-ionizing Radiation: Wireless Phones
Exposures from cellphones, cordless
phones, walkie-talkies, baby monitors
Risk of brain tumors
Energy cannot break molecular bonds
Creates free radicals; increases lifetime
of free radicals
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
8
Non-ionizing Radiation: Wireless Phones
Increased 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]
9
Wireless Phones: Risk by Age [2]
Increased Risk of Brain Tumor
800%
700%
600%
500%
400%
300%
200%
100%
0%
20-80 years
20-29 years
20-80 years
Analog cellphone
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
20-29 years
Cordless phone
10
Non-ionizing Radiation: Wireless Phones
Increased 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]
11
Non-ionizing Radiation: Digital Cellphones
Latency 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]
12
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]
13
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]
14
Wireless Phones:Years of Exposure [4, 5]
Increased Risk of Brain Tumor by Year of
Wireless Phone Use
Acoustic
Neuroma
Meningio ma
Acoustic
Neuroma
Digital
>15 years
Acoustic
Neuroma
Cordless Anaog
>10 years
Meningio ma
Digital
>5 to 10 years
Meningio ma
Anaog
Brain
Cancer
Brain
Cancer
300%
250%
200%
150%
100%
50%
0%
1 to 5 years
Brain
Cancer
Increased
risk
Cordless Anaog
Digital
Cordless
Wireless Phone Type
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
15
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]
16
Scatter Plots (following slides)
Vertical axis is percentage confidence of a
finding
Horizontal axis is excess (or decrease) risk of
a brain tumor of a finding
Risk 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]
17
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]
18
Industry studies compared to independent studies [5, 9, 11]
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
19
Industry studies compared to independent studies [4, 8, 6, 7]
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
20
Industry studies compared to independent studies [4, 6, 7]
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
21
A Speculation
What 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]
22
Summation
Ionizing Radiation
Non-ionizing Radiation
Young at greater risk
Latency time
Young at greater risk
Latency time
• Brain cancer, 20-30
years
• Brain cancer, 1-5/> 10
years
– Increased risk 55%
– Increased risk 60%/260%
• Meningioma, 30-40 yrs
• Meningioma, >10 years
– Increased risk 37%
Power
– 60%
Power
• Increasing risk with
increasing power
• Increasing risk with
increasing power
Dose measure in Gray
Dose measure in Gray
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
23
Conclusion: A Query
Is the non-ionizing radiation
exposure from wireless phone use a
greater risk for brain tumors than
ionizing radiation?
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 urban
and 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]
25
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
Revised 22 March 2006
Lloyd Morgan
email: [email protected]
26