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OCR for page 209
Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Appendix A
Tables
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
TABLE A3-1 In Vitro Assays of Electric-and Magnetic-Field Exposure and Genotoxicity
Study
Cell Type
Exposure Characteristics
Electric-Field Strength of Culture Media
End Points Evaluated
Outcome
Hungate et al. 1979
Salmonella TA100 or TA98 exposed 20 hr in liquid nutrient broth suspension
200-800 kV/m electric field in air
Cannot be determined from report
Mutation
1.5-3-fold increase in mutation frequency in TA100 at 800,000 V/m
Moore 1979
Salmonella TA98 and TA100 tester strains exposed during growth in nutrient broth for 5-24 hr
0.3-Hz triangular magnetic field at 0.015 and 0.03 T
Induced electric field cannot reliably be estimated from report
Reverent assay
No significant effects observed
Wolff et al. 1980
CHO cells exposed 4 hr (SCEs) or 13 hr (chromosomal aberration)
NMR gradient field; 1.82 pulses/sec, 4.6 T/sec; coexposed 0.352-T static magnetic field and 5-mW/cm2 magnetic field at 15 MHz
Cannot be determined from report
Chromosomal aberrations and SCEs
No significant effects observed
Wolff et al. 1980
CHO cells exposed 4 hr (SCEs) or 13 hr, 40 min (chromosomal aberration)
0.35 T plus coexposure to RF field at 15 MHz, 5 mW/cm2 and time-varying magnetic-field changes at 4.6 T/sec and 1.82 T/sec
0
Chromosomal aberrations and SCEs
No significant effects observed
Cooke and Morris 1981
Human lymphocytes exposed 1 hr
0.5-1.0 T
0
Chromosomal aberrations and SCEs
No significant effects observed
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Thomas and Morris 1981
E. coli AB1157 exposed 5 hr (agar plates)
1.0 R ± coexposure to RF field at 1 mW/cm2 and gradient magnetic field at 1-12 T/sec
Not calculated
Revertant assay
No significant effects observed
Thomas and Morris 1981
recA, uvrA, or recA urvA E. coli: exposed 5 hr in Petri dishes
1.0 T
0
Survival (recA, uvrA, or recA uvrA E. coli mutants) compared with wild type
No significant effects observed
Thomas and Morris 1981
E. coli recA, uvrA, and recA uvrA mutants or E. coli AB 1157 exposed 40 min or 5 hr on agar Petri plates
Gradient magnetic field at 1-12 T/sec; coexposure to 0.094-T static magnetic field and 1-mW/cm2 RF field
2-30 mV/m calculated from exposure apparatus by McCann et al. (1993)
Revertant assay
No significant effects observed
Mileva 1982
Human peripheral lymphocytes: exposed 15-360 min
0.3 T
0
Chromosomal aberrations
No significant effects observed
Nordenson et al. 1984
Human peripheral lymphocytes exposed 3 hr to phytohemagglutinin stimulation
50-Hz sinusoidal field applied through agarose bridges
14 V/m (10 A/m2) calculated from exposure apparatus by McCann et al. (1993)
Chromosomal aberrations
No significant effects observed
Nordenson et al. 1984
Human peripheral lymphocytes in whole blood exposed 1 min before phytohemagglutinin stimulation
10 spark discharge pulses, 2 msec wide
250-350 kV/m
Chromosomal aberrations
At the highest dose, a significant increase in chromosomal breaks
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Study
Cell Type
Exposure Characteristics
Electric-Field Strength of Culture Media
End Points Evaluated
Outcome
d'Ambrosia et al. 1985
Bovine lymphocytes in liquid culture medium exposed 72 hr by applying external electrodes to side walls of culture flasks
50-Hz sinusoidal field with 11% THD applied through capacitative coupling
0.016 V/m (0.024 A/m2)
Chromosomal aberrations
A significant increase (& sim;3-fold) in chromosomal aberrations for three experiments
Cohen 1986; Cohen et al. 1986a,b
Peripheral blood lymphocytes from normal individuals (Cohen et al. 1986b) and individuals with chromosomal instability syndromes exposed 69-hr culture period
60-Hz sinusoidal field applied through agarose bridges and coexposure to 60-Hz sinusoidal magnetic field at 10-200 µT (38-75 mT/sec)
0.24 V/m (0.2 A/m2) (no reliable estimate available from published report)
Chromosomal aberrations and SCEs
No significant effects observed
Cohen et al. 1986a,b
Peripheral blood lymphocytes normal (Cohen et al. 1986b) and with chromosomal instability exposed 69 hr in culture
60-Hz sinusoidal field, circularly polarized, at 10-200 µT (38-75 mT/sec)
0.7-13 mV/m calculated from exposure apparatus by McCann et al. (1993); coexposure to 60-Hz sinusoidal electric field, 0.24 V/m (0.3 A/m2) (McCann et al. 1993)
Chromosomal aberrations and SCEs
No significant effects observed
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Juutilainen and Liimatainen 1986
Salmonella TA100 and TA98 exposed in top agar or liquid nutrient broth culture for 48 or 6.5 hr, respectively
100-Hz sinusoidal field at 0.13, 1.3, 13, and 130 µT
0.2, 2.0, 20, and 200 µV/m (Petri dishes); and 1.5, 15, 150, and 1,500 µV/m (flasks) calculated from exposure apparatus by McCann et al. (1993)
Revertant assay
No significant effects observed
Livingston et al. 1986, 1991
Human lymphocytes or CHO cells exposed 24-96 hr or 72 hr, respectively
60-Hz sinusoidal field applied through agarose bridges
0.024-24 V/m (no reliable estimate available from published report) (0.03-30 A/m2)
Chromosomal aberrations
No significant effects observed
Livingston et al. 1986, 1991
Peripheral blood lymphocytes or CHO cells exposed 24-96 hr or 72 hr, respectively
60-Hz sinusoidal field, circularly polarized, at 0.22 mT (0.082 T/sec)
0.7-13 mV/m calculated from exposure apparatus by McCann et al. 1993; coexposure to 60-Hz sinusoidal electric field at 0.024-24 V/m
SCEs and micronuclei
No significant effects observed
Whitson et al. 1986
Normal human fibroblasts previously or post irradiated with UV light (254 nm) exposed up to 48 hr
60-Hz applied through capacitative coupling; field in air outside media 10 kV/m
0.4 mV/m
DNA single-strand breaks assayed via 5-bromodeoxyuridine photolysis; pyrimidine dimers assayed using hydrolysis then two-dimensional paper chromatography, or
No significant effects observed
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Study
Cell Type
Exposure Characteristics
Electric-Field Strength of Culture Media
End Points Evaluated
Outcome
by treating cells with a UV-specific endonuclease followed by a fragment sizing analysis on sucrose gradients
Takahashi et al. 1987
Chinese hamster V79 cells exposed 24 hr
100-Hz saw-toothed field at 0.180-2.500 mT (7.2-100 T/sec)
0.02-0.33 V/m calculated from exposure apparatus by McCann et al. (1993)
SCEs
No significant effects observed
d'Ambrosia et al. 1988-1989
Bovine lymphocyte cultures exposed 3 or 45 hr
50-Hz sinusoidal field applied through agarose bridges
0.77-7.7 V/m (1-10 A/m2)
Chromosomal aberrations
Significant increases in chromatid breaks at high exposure level reported after 45-hr exposure and in total aberrations in one of two cultures tested after 3-hr exposure
Reese et al. 1988
CHO cells exposed 1 hr
60-Hz sinusoidal field applied through agarose bridges; coexposure to 60-Hz sinusoidal field at 0-2 mT
1-38 V/m
DNA single-strand breaks
No significant effects reported
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Reese et al. 1988
CHO cells exposed 1 hr
60-Hz sinusoidal field at 2 mT (0.75 T/sec); coexposed to 60-Hz sinusoidal electric field at 0-38 V/m
8 mV/m calculated by McCann et al. (1993)
DNA repair measured by alkaline elution
No significant effects observed
Bersani et al. 1989
Human peripheral lymphocytes or two human cell lines were exposed 48 hr
50-Hz saw-toothed field at 2.5 mT peak strength (1 T/sec; induced pulse 2-msec wide at 2 mV/m)
2 mV/m
DNA single-strand breaks
No significant effects observed
Cossarizza et al. 1989; Bersani et al. 1989
Human lymphocytes exposed 6 hr after some cultures irradiated with 100-Gy 60Co
50-Hz saw-toothed field at 2.5 mT peak strength (1 T/sec; induced pulse 2-msec wide at 2 mV/m)
2 mV/m
Unscheduled DNA synthesis
No significant effects observed
Peteiro-Cartelle and Cabezas-Cerrato 1989
Human lymphocytes exposed 3 hr or simultaneously cultured and exposed 72-96 hr
0.045-0.125 T
0
Chromosomal aberrations and SCEs
No significant effects observed
Rosenthal and Obe 1989
Human peripheral lymphocytes cultured 72 hr in magnetic field
50-Hz sinusoidal field at 0.1-7.5 mT (0.031-2.4 T/sec)
0.1-8 mV/m calculated from exposure apparatus by McCann et al. (1993)
SCEs
No significant effects observed
Rosenthal and Obe 1989
Human peripheral lymphocytes pretreated with NMU, DEB, or trenimon and cultured up to 72 hr in presence of magnetic field
50-Hz sinusoidal field at 0.5-2 mT (0.16-0.63 T/sec) with coexposure to NMU or trenimon
0.61-2 mV/m
SCEs
Statistically significant (p < 0.05) increase in SCEs only in cells treated with NMU or trenimon
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Study
Cell Type
Exposure Characteristics
Electric-Field Strength of Culture Media
End Points Evaluated
Outcome
Takatsuji et al. 1989
Human peripheral lymphocytes exposed <30 min
1.1 T + coexposure to protons and alpha particles
0
Chromosomal aberrations
Proton coexposure significant dose-response effect; frequency of dicentrics increased for both coexposures
Frazier et al. 1990
Human peripheral lymphocytes previously exposed to γ-irradiation (5 Gy) exposed 0-30 min during repair
60-Hz sinusoidal fields applied through agarose bridges; coexposure to γ radiation, 60-Hz sinusoidal magnetic field at 0-0.001 T
1-20 V/m
DNA single-strand breaks
No significant effects reported
Garcia-Sagredo et al. 1990
Peripheral blood lymphocytes or CHO cells exposed 24-96 hr or 72 hr, respectively
4.4-kHz saw-toothed pulses of 5 msec width, 14 pulses per sec at 1-4 mT peak strength (50-200 T/sec)
0.07-0.27 V/m calculated from exposure apparatus by McCann et al. (1993)
SCEs
No significant effects observed
Balcer-Kubiczek and Harrison 1991
C3H/10T1/2 cells exposed 24 hr; post-exposure of some cells with TPA, either preceded or followed by X-rays given at 0.5, 1, or 1.5 Gy
2.45-GHz microwaves pulse modulated at 120 Hz with electric fields at 18, 56, or 120 V/m and magnetic fields at 0.09, 0.27, or 0.56 µT
Not calculated
Cell survival and neoplastic transformation
EMF alone demonstrated no effect; transformation due to EMF plus TPA highly significant; neoplastic transformation dependent on level of EMF exposure and additive of X-rays given as a cocarcinogen
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
García-Sagredo and Monteagudo 1991
Human peripheral lymphocytes cultivated in vitro 72 hr and exposed over the last 24 hr to magnetic fields
Quasi-rectangular pulses lasting 26 µsec, frequency 4.4 kHz, in trains of 5 msec at 14-Hz repetition rate with peak strength at 1, 2, and 4 mT
Not calculated
Chromosomal aberrations
Significant effect observed at 4 mT; no significant effects observed at 1 and 2 mT
Khalil and Qassem 1991
Human lymphocytes grown 24, 48, or 72 hr in presence of the magnetic field
50-Hz pulsed field at 1 mT (0.72 T/sec)
0.043 V/m
Chromosomal aberrations
Significant decreases in mitotic index; increases in chromosomal aberrations for all exposure periods; slight increase in SCEs (p < 0.05) only for 72 hr
Novelli et al. 1991
Saccharomyces cerevisiae cultures exposed up to 24 hr and then examined by pulsed-field gel electrophoresis (PFGE)
50-Hz electric-and magnetic-field exposure consisting of 4 units: 1. uniform magnetic field; 2. uniform electric field; 3. orthogonal uniform electric and magnetic field; and 4. no field control with electric field from 0.1-20 kV/m and magnetic field from 0.2-200 µT
Not calculated
DNA double-strand breaks
No significant effects observed
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Study
Cell Type
Exposure Characteristics
Electric-Field Strength of Culture Media
End Points Evaluated
Outcome
Scarfi et al. 1991
Human lymphocytes grown 72 hr in the magnetic field
50-Hz saw-toothed field at 0.025 T (some cell cultures coexposed to mitomycin C)
0.005 V/m
Micronuclei
No significant effects observed
Fiorani et al. 1992
Cultured K562 human tumor cells exposed 1, 4, 6, 12, or 24 hr
50-Hz electric field at 0.2-20 kV/m and magnetic field at 0.2-200 µT
Not calculated
DNA single-strand breaks and cell growth
No significant effects observed
Chahal et al. 1993
E. coli K-12 strain AB1157, and its derivatives TK702 umuC (deficient in error prone repair) and TK501 umuC uvrB (lacking both error prone and excision repair) exposed 1 or 16 hr
1-Hz electric field at 3 kV/m for 1 hr or 1 kV/m for 16 hr alone or in combination with UV and/or mitomycin C
Not calculated
Mutations
No significant effects observed
Fiorio et al. 1993
Chinese hamster V79 cells exposed 10 days
50-Hz sinusoidal magnetic field at 200 µT
Not calculated
Chromosomal aberrations, SCEs, and cell survival
No significant increase in chromosomal aberrations or SCEs; cell viability decreased by 50% after 10 days with only 100 plated; however, no reduction in viability with 2 × 105 seeded cells
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Scarfí et al. 1993
Human peripheral lymphocytes exposed 72 hr and assayed using the cytokinesis-block micronucleus assay
50-Hz ac sinusoidal electric field at 0.5, 2, 5, and 10 kV/m
Not calculated
Micronuclei
No significant effects observed
Zwingelberg et al. 1993
Cultured rat peripheral lymphocytes exposed 7-28 days, 24 hr/day
Homogenous 50-Hz, magnetic field at 30 mT
Not calculated
SCEs and chromosomal aberrations
No significant effects observed
Fairbairn and O'Neill 1994
HL-60 cells, Raji cells, HeLa cells, and human peripheral lymphocytes exposed 2-30 min
50-Hz magnetic field with peak amplitude at 5 mT and pulse duration of 3 msec
Not calculated
DNA single-strand breaks
No significant effect observed
Libertin et al. 1994
HeLa cells transfected with a CAT construct transcriptionally driven by HIV-LTR promoter exposed 24 or 48 hr
ac field: 10 Hz-1.6 kHz, 0.07-35 µT; dc field: 170 µT
Not calculated
HIV-LTR expression
No significant effects observed
Nordenson et al. 1994
Human amniotic cells exposed 72 hr continuously and intermittently (15 sec on, 15 sec off; 2 sec on, 20 sec off)
50-Hz magnetic field at 30 µT (rms) and 300 µT
Not calculated
Chromosomal aberrations
A significant increase observed in intermittently exposed cells; no significant increase seen in continuously exposed cells
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
TABLE A5-7 Electric-and Magnetic-Field Exposure and Childhood Cancers Other than Leukemia and Brain Cancer: Results
Study
Exposure Category
Number of Cases
Number of Controls
Crude ORa
95% CIb
Potential Confounders Addressedc
Wertheimer and Leeper 1979
Birth addresses:
Age of onset, sex, socioeconomic status, urban residence, family pattern, traffic congestion
HCCd
17
9
2.4
0.9-6.1
LCCe
31
39
Death addresses:
HCC
18
17
1.1
0.5-2.4
LCC
45
46
Tomenius 1996
Total residences:
Age, sex, church district of birth
=0.3 µT
11
0
<0.3 µT
352
309
Savitz et al. 1988
Field measurements for low-power conditions:
Maternal age, father's education, family income, maternal smoking in pregnancy, traffic density, age, sex, geographic area of residence
>0.2 µT
1
16
0.3
0.4-2.1
<0.2 µT
39
191
Field measurements for high-power conditions:
>0.2 µT
3
29
0.5
0.1-1.7
<0.2 µT
37
175
Two-level wire codes:
High
28
52
1.5
0.9-2.6
Low
74
207
Wire codes:
Very high
4
8
1.6
0.5-5.8
Very low
27
88
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Study
Exposure
Cases Observed
Cases Expectedf
Crude ORa
95% CIb
Potential Confounders Addressedc
Verkasalo et al. 1993
≥ 0.2 µT
3
2.42
1.2
0.3-3.6
Age, sex
0.01-0.19
48
44.7
1.1
0.8-1.4
≥0.4 µT-yr
4
1.0
0.3-2.6
0.01-0.39
47
1.1
0.8-1.4
a Odds ratio calculated without consideration of possible confounders (ratio of exposed to unexposed cases divided by the ratio of exposed to unexposed controls).
b 95% confidence interval for the odds ratio calculated without consideration of possible confounders.
c Includes all factors considered to be potential confounders whether or not statistical adjustments were made for them.
d HCC, high current configuration.
e LCC, low current configuration.
f Cases expected on the basis of incidence data for the disease in the general population.
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
TABLE A5-8 Residential Electric-and Magnetic-Field Exposure and All Childhood Cancers: Results
Study
Exposure Category
Number of Cases
Number of Controls
Crude ORa
95% CIb
Adjusted ORc
Potential Confounders Addressedd
Wertheimer and Leeper 1979
Birth address:
Age of onset, sex, traffic congestion, socioeconomic status (SES), urban residence, family pattern
HCCe
101
55
2.3
1.6-3.4
LCCf
171
217
Death address:
HCC
129
74
2.2
1.6-3.1
LCC
199
254
Tomenius 1986
Total residences:
Age, sex, church district of birth, permanent vs. transient residence
≥0.3 µT
34
14
2.1
1.1-4.0
<0.3 µT
1,095
955
Savitz et al. 1988
Field measurements for low-power conditions:
Maternal age, father's education, family income, maternal smoking in pregnancy, traffic density, age, sex, geographic area of residence
>0.2 µT
13
16
1.4
0.6-2.9
(1.2-1.5)
<0.2 µT
115
191
Field measurements for high-power conditions:
>0.2 µT
19
29
1.0
0.6-2.0
<0.2 µT
110
175
Two-level wire codes:
High
89
52
1.5
1.0-2.3
Low
231
207
Wire codes:
Very high
19
8
2.2
1.0-5.2
Very low
95
88
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Myers et al. 1990
Distance to power line:
Age, sex, residence type, county of birth
<25 m
13
17
1.1
0.5-2.6
≥25 m <50 m
7
15
0.7
0.3-2.0
≥50 m <75 m
10
17
1.0
0.5-2.2
≥75 m <100 m
8
9
1.5
0.6-4.0
<100 m
38
58
1.0
0.6-1.7
≥100 m
336
530
Estimated field:
≥0.1 µT
1
4
0.4
0.04-4.1
≥0.03 µT <0.1 µT
8
4
2.6
0.8-9.0
≥0.01 µT <0.03 µT
7
13
1.0
0.4-2.5
≥0.01 µT <0.1 µT
15
17
1.4
0.6-3.0
≥0.01 µT
16
21
1.2
0.6-2.6
<0.01 µT
358
567
Feychting and Ahlbom 1993
Estimated field:
Sex, age, county, residence type, diagnosis year, SES, NO2
≥0.3 µT
10
32
1.3
0.6-2.7
0.1-0.29 µT
14
47
1.2
0.6-2.3
≥0.2 µT
12
46
1.1
0.5-2.1
0.1-0.19 µT
12
33
1.5
0.7-2.9
<0.1 µT
117
475
Olsen et al. 1993
Estimated field:
Age, sex, age at diagnosis
≥0.4 µT
6
3
5.6
1.6-19
0.1-0.39 µT
4
17
0.7
0.2-2.0
≥0.25 µT
6
11
1.5
0.6-4.1
0.1-0.24 µT
4
9
1.3
0.4-4.1
≥0.1 µT
10
20
1.4
0.7-3.0
<0.1 µT
4
21
0.6
0.2-17
Not exposed, distant
16
49
0.9
0.5-1.6
Not exposed
1,677
4,698
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Study
Exposure Category
Cases Observed
Cases Expectedg
Standardized Incidence Ratio
95% CIb
Potential Confounders Addressedd
Verkasalo et al. 1993
≥ 0.2 µT
11
7.39
1.5
0.7-2.7
Age, sex
0.01-0.19 µT
129
137.17
0.9
0.8-1.1
≥ 0.4 µT-yr
15
1.4
0.8-2.3
0.01-0.39 µT-yr
125
0.9
0.8-1.1
a Odds ratio calculated without consideration of possible confounders (ratio of exposed to unexposed cases divided by the ratio of exposed to unexposed controls).
b 95% confidence intervals for the odds ratio calculated without consideration of possible confounders.
c Odds radio adjusted statistically for possible confounding factors.
d Includes all factors considered to be potential confounders whether or not statistical adjustments were made for them.
e HCC, high current configuration.
f LCC, low current configuration.
g Cases expected on the basis of incidence data for the disease in the general population.
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
TABLE A5-9 Residential Electric-and Magnetic-Field Exposure and Cancer: Results of Cohort Studies Including Subjects of All Ages
Study
Exposure Description
Number of Cases Observed
SMRa
95% CIb
Potential Confounders Addressedc
McDowell 1986
Distance from power line for Leukemia:
Age, sex, calendar time
0-14 m
1
1.4
0.0-8.0
15-34 m
2
0.8
0.1-2.8
35-50 m
3
1.2
0.3-3.5
Lymphoma:
0-14 m
3
3.3
0.7-9.7
15-34 m
2
0.6
0.1-2.1
35-50 m
5
1.5
0.5-3.4
All cancers:
0-14 m
27
1.0
0.7-1.5
15-34 m
97
1.1
0.9-1.3
35-50 m
89
1.0
0.8-1.2
Schreiber et al. 1993
Wire codes:
Age, sex
High exposure
0
Low exposure
3
1.3
0.3-3.9
Hodgkin's disease:
High exposure
2
4.7
0.5-17.0
Low exposure
0
Non-Hodgkin's lymphoma:
High exposure
2
1.8
0.2-6.4
Low exposure
0
Brain tumors:
High exposure
0
Low exposure
3
2.0
0.4-5.7
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Study
Exposure Description
Number of Cases Observed
SMRa
95% CIb
Potential Confounders Addressedc
All cancers:
High exposure
46
0.9
0.6-1.1
Low exposure
65
0.9
0.7-1.2
a Standard mortality ratio, ratio of observed number of deaths to the number expected based on mortality in the general population.
b 95% confidence intervals for the odds ratio calculated without consideration of possible confounders.
c Includes all factors considered to be potential confounders whether or not statistical adjustments were made for them.
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
TABLE A5-10 Residential Electric-and Magnetic-Field Exposure and Adult Leukemia: Results
Study
Exposure Description
Number of Cases
Number of Controls
Crude ORa
95% CIb
Potential Confounders Addressedc
Wire codes at time of longest residence:
Age, sex, family income, race, cigarette smoking
Very high
5
6
0.8
0.2-2.9
High
21
23
0.8
0.4-1.7
Low
21
37
0.6
0.3-1.2
Very low
42
44
Wire codes at residence closest to reference date:
Very high
5
7
0.8
0.2-2.9
High
24
19
1.4
0.6-3.0
Low
26
38
0.8
0.4-1.6
Very low
42
52
Estimated field at longest residence:
>0.2 µT
14
18
0.8
0.3-1.8
0.05-0.199 µT
46
64
0.7
0.4-1.3
0.0-0.05 µT
29
28
Estimated field at residence closest to reference date:
>0.2 µT
23
25
1.0
0.5-2.0
0.05-0.1992 µT
70
92
0.8
0.5-1.4
0.0-0.052 µT
40
42
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Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Study
Exposure Description
Number of Cases
Number of Controls
Crude ORa
95% CIb
Potential Confounders Addressedc
Field measurement mean exposure for low power:
>0.2 µT
1.5
0.5-4.7
0.05-0.1992 µT
1.2
0.5-2.6
0.0-0.052 µT
Field measurement mean exposure; for low power:
>0.2 µT
1.6
0.5-5.0
0.05-0.1992 µT
0.6
0.3-1.2
0.0-0.052 µT
Coleman et al. 1989
Distance to substation, using population controls:
0-24 m
4
4
1.3
(0.3-5.3)
25-49 m
11
13
1.1
(0.5-2.5)
50-99 m
63
69
1.2
(0.8-1.8)
≥100 m
112
145
—
—
Youngson et al. 1991
Distance from power line:
<25 m
77
62
1.3
(0.9-1.8)
≥25 m <50 m
60
47
1.3
(0.9-1.9)
≥50 m <75 m
52
50
1.1
(0.7-1.6)
≥75 m <100 m
47
53
0.9
(0.6-1.3)
<100 m
236
212
1.1
(0.9-1.4)
≥100 m
2,908
2,932
—
—
OCR for page 283
Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
Estimated magnetic field:
Age, sex, residence type
≥0.3 µT
15
8
1.9
(0.8-4.4)
≥0.1 µT
129
125
1.0
(0.7-1.5)
Feychting and Ahlbom 1994
Estimated magnetic field:
Age, sex
≥0.2 µT
26
83
1.0
0.7-1.7
0.1-0.19 µT
20
76
0.9
0.5-1.5
>0.09 µT
278
924
—
—
a Odds ratio calculated without consideration of possible confounders (ratio of exposed to unexposed cases divided by the ratio of exposed to unexposed controls).
b 95% confidence intervals for the odds ratio calculated without consideration of the possible confounders.
c Includes all factors considered to be potential confounders whether or not statistical adjustments were made for them.
OCR for page 284
Possible Health Effects of Exposure to Residential Electric and Magnetic Fields
TABLE A5-11 Residential Electric-and Magnetic-Field Exposure and Adult Cancer: Results
Study
Exposure Description
Number of Cases
Number of Controls
Crude ORa
Adjusted 95% CIb
Potential Confounders Addressedc
Wertheimer and Leeper 1892
Wire codes:
Sex, age, socioeconomic status, onset age, urban exposure
VHCCd
108
74
2.2
1.5-3.2
OHCCe
330
298
1.7
1.2-2.2
OLCCf
642
659
1.5
1.1-1.9
End poleg
99
148
a Odds ratio calculated without consideration of possible confounders (ratio of exposed to unexposed cases divided by the ratio of exposed to unexposed controls).
b 95% confidence intervals for the odds ratio calculated without consideration of possible confounders.
c Includes all factors considered as potential confounders whether or not statistical adjustments were made for them.
d VHCC, very high current configuration.
e OHCC, ordinary high current configuration.
f OLCC, ordinary low current configuration.
g End pole, very low current configuration.
Representative terms from entire chapter:
blood melatonin