ELECTROMAGNETICS FIELDS AND CANCER: QUOTATIONS

1 Bioelectromagnetics in morphogenesis.
2 Possible associations between ELF electromagnetic fields, DNA damage response processes and childhood leukaemia.

3 Exposure of human peripheral blood lymphocytes to electromagnetic fields associated with cellular phones leads to chromosomal instability.
4 Induction of DNA strand breaks by intermittent exposure to extremely-low-frequency electromagnetic fields in human diploid fibroblasts.
5 Does our electricity distribution system pose a serious risk to public health?
6 Decreased DNA repair rates and protection from heat induced apoptosis mediated by electromagnetic field exposure.
7 Effects of static magnetic field on human leukemic cell line HL-60.
8 Immunotropic effects of electromagnetic fields in the range of radio- and microwave frequencies
9
Study of high- and low-current-configuration homes from the 1988 Denver Childhood Cancer Study.
10 Exposure to power frequency electric fields and the risk of childhood cancer in the UK.
11 Childhood cancer in relation to indicators of magnetic fields from ground current sources.
12 Electromagnetic field exposures and childhood cancers in New Zealand.

Association between magnetic fields and childhood leukemia.
13 Exposure to residential electric and magnetic fields and risk of childhood leukaemia (1991)
14 Hypothesis: the risk of childhood leukemia is related to combinations of power-frequency and static magnetic fields.(1994)
15 Combined risk estimates for two German population-based case-control studies on residential magnetic fields and childhood acute leukemia.(Gen 1998)

16 [Synthesis of the epidemiological evidence concerning childhood leukemia in relation to exposure to 50 Hz. electric and magnetic fields] (Apr 1998)
17 Power-frequency electric and magnetic fields and risk of childhood leukemia in Canada. (Mag 1999)
18 Childhood leukemia and personal monitoring of residential exposures to electric and magnetic fields in Ontario, Canada. (Giu 1999)
19 A case-control study of childhood leukemia in southern Ontario, Canada, and exposure to magnetic fields in residences (Lug 1999)

20 Residential magnetic fields predicted from wiring configurations: II. Relationships To childhood leukaemia (Ott 1999)
21 A pooled analysis of magnetic fields and childhood leukaemia (Sett 2000)
22 [Infantile leukemia and exposure to 50/60 Hz magnetic fields: review of epidemiologic evidence in 2000]

23 Residential magnetic fields as a risk factor for childhood acute leukaemia: results from a German population-based case-control study.(Mar 2001)
24 The potential impact of bias in studies of residential exposure to magnetic fields and childhood leukemia.(5-2001)

25 Residential EMF exposure and childhood leukemia: meta-analysis and population attributable risk.(5-2001)
26 Do studies of wire code and childhood leukemia point towards or away from magnetic fields as the causal agent? (5-2001)

27 Factors that explain the power line configuration wiring code-childhood leukemia association: what would they look like? (5-2001)
28 Leukemia mortality and incidence of infantile leukemia near the Vatican Radio Station of Rome (Nov-Dic 2001)
29 Adult and childhood leukemia near a high-power radio station in Rome, Italy.(Giu 2002)

30 Childhood leukemia and magnetic fields in infant incubators ( Gen 2002)
31 Potential motion related bias in the worn dosimeter measurements of two childhood leukemia studies.(Lug 2002)
32 Contact voltage measured in residences: implications to the association between magnetic fields and childhood leukemia.(Sett 2002)
33 Correlation of year-to-year magnetic field exposure metrics among children in a leukemia survival study.(Nov 2002)
34 Interactive effect of chemical substances and occupational electromagnetic field exposure on the risk of gliomas and meningiomas in Swedish men.
35 Epidemiology of primary brain tumors: current concepts and review of the literature.
36 Electromagnetic fields and breast cancer on long island: a case-control study.

1 Bioelectromagnetics in morphogenesis.
Levin M.
Department of Cytokine Biology, The Forsyth Institute, Boston, Massachusetts.
Understanding the factors that allow biological systems to reliably self-assemble consistent, highly complex, four dimensional patterns on many scales is crucial for the biomedicine of cancer, regeneration, and birth defects. The role of chemical signaling factors in controlling embryonic morphogenesis has been a central focus in modern developmental biology.
While the role of tensile forces is also beginning to be appreciated, another major aspect of physics remains largely neglected by molecular embryology: electromagnetic fields and radiations.
The continued progress of molecular approaches to understanding biological form and function in the post-genome era now requires the merging of genetics with functional understanding of biophysics and physiology in vivo.
The literature contains much data hinting at an important role for bioelectromagnetic phenomena as a mediator of morphogenetic information in many contexts relevant to embryonic development. This review attempts to highlight briefly some of the most promising (and often underappreciated) findings that are of high relevance for understanding the biophysical factors mediating morphogenetic signals in biological systems. These data originate from contexts including embryonic development, neoplasm, and regeneration. 
Bioelectromagnetics. 2003 Jul;24(5):295-315

2 Possible associations between ELF electromagnetic fields, DNA damage response processes and childhood leukaemia.
Hone P, Edwards A, Halls J, Cox R, Lloyd D.
National Radiological Protection Board, Chilton, Didcot, OX11 0RQ, UK.
Epidemiology has shown an association between exposure to extremely low frequency (ELF) electromagnetic fields (EMF) and childhood leukaemia. The causal nature and biological basis of this association are however questionable. Studies with aneuploid cell lines raised the hypothesis that ELF EMF may act as a coleukaemogen by compromising DNA damage response to genotoxic agents such as ionising radiation. We examined this hypothesis using gamma-ray-induced dicentric chromosome exchange in human lymphocytes. The results from 12 h post-gamma-ray exposure to fields of 0.23, 0.47 and 0.7 mT provide no support to the hypothesis. The power of the study was sufficient to exclude an ELF enhancement of chromosomal exchange of 10-15% (2SE).British Journal of Cancer (2003) Jun 16;88(12):1939-41. www.bjcancer.com

3 Exposure of human peripheral blood lymphocytes to electromagnetic fields associated with cellular phones leads to chromosomal instability.
Mashevich M, Folkman D, Kesar A, Barbul A, Korenstein R, Jerby E, Avivi L.

Department of Human Genetics and Molecular Medicine, Tel-Aviv University, Tel-Aviv, Israel.
Whether exposure to radiation emitted from cellular phones poses a health hazard is at the focus of current debate. We have examined whether in vitro exposure of human peripheral blood lymphocytes (PBL) to continuous 830 MHz electromagnetic fields causes losses and gains of chromosomes (aneuploidy), a major "somatic mutation" leading to genomic instability and thereby to cancer. PBL were
irradiated at different average absorption rates (SAR) in the range of 1.6-8.8 W/kg for 72 hr in an exposure system based on a parallel plate resonator at temperatures ranging from 34.5-37.5 degrees C. The averaged SAR and its distribution in the exposed tissue culture flask were determined by combining measurements and numerical analysis based on a finite element simulation code. A linear increase in chromosome 17 aneuploidy was observed as a function of the SAR value, demonstrating that this radiation has a genotoxic effect. The SAR dependent aneuploidy was accompanied by an abnormal mode of replication of the chromosome 17 region engaged in segregation (repetitive DNA arrays associated with the centromere), suggesting that epigenetic alterations are involved in the SAR dependent genetic toxicity. Control experiments (i.e., without any RF radiation) carried out in the temperature range of 34.5-38.5 degrees C showed that elevated temperature is not associated with either the genetic or epigenetic alterations observed following RF radiation-the increased levels of aneuploidy and the modification in replication of the centromeric DNA arrays. These findings indicate that the genotoxic effect of the electromagnetic radiation is elicited via a non-thermal pathway. Moreover, the fact that aneuploidy is a phenomenon known to increase the risk for cancer, should be taken into consideration in future evaluation of exposure guidelines.
Bioelectromagnetics. 2003 Feb;24(2):82-90.


4 Induction of DNA strand breaks by intermittent exposure to extremely-low-frequency electromagnetic fields in human diploid fibroblasts.
Ivancsits S, Diem E, Pilger A, Rudiger HW, Jahn O.
Division of Occupational Medicine, University Hospital/AKH, Waehringer Guertel 18-20, A-1090 Vienna, Austria. sabine.ivancsits@akh-wien.ac.at
Results of epidemiological research show low association of electromagnetic field (EMF) with increased risk of cancerous diseases and missing dose-effect relations.
An important component in assessing potential cancer risk is knowledge concerning any genotoxic effects of extremely-low-frequency-EMF (ELF-EMF).
Human diploid fibroblasts were exposed to continuous or intermittent ELF-EMF (50Hz, sinusoidal, 24h, 1000microT). For evaluation of genotoxic effects in form of DNA single- (SSB) and double-strand breaks (DSB), the alkaline and the neutral comet assay were used. In contrast to continuous ELF-EMF exposure, the application of intermittent fields reproducibly resulted in a significant increase of DNA strand break levels, mainly DSBs, as compared to non-exposed controls. The conditions of intermittence showed an impact on the induction of DNA strand breaks, producing the highest levels at 5min field-on/10min field-off. We also found individual differences in response to ELF-EMF as well as an evident exposure-response relationship between magnetic flux density and DNA migration in the comet assay.
Our data strongly indicate a genotoxic potential of intermittent EMF. This points to the need of further studies in vivo and consideration about environmental threshold values for ELF exposure.
Mutat Res. 2002 Aug 26;519(1-2):1-13.

5
Does our electricity distribution system pose a serious risk to public health?
Henshaw DL.
University of Bristol, HH Wills Physics Laboratory, UK. d.l.henshaw@bristol.ac.uk
Elevated magnetic field exposures are associated with increased childhood leukaemia risk. A link with breast and other cancers has been postulated via modified melatonin activity. Other illnesses have been linked to electricity distribution, by association or mechanistic considerations. For selected illnesses, this paper estimates the annual number of excess cases that might occur near high-voltage powerlines in the UK.
Within 150m of powerlines, magnetic field exposures above 0.1 microT are postulated to result in 9000 excess cases of depression in adults and 60 cases of suicide.
Electric field effects can mediate increased exposure to air pollution.
Within 400m of powerlines, this may result annually in 200-400 excess cases of lung cancer, 2000-3000 cases of other illnesses associated with air population and 2-6 cases of childhood leukaemia. Seventeen cases of non-melanoma skin cancer might occur by exposure directly under powerlines
Med Hypotheses.
2002 Jul;59(1):39-51.

6 Decreased DNA repair rates and protection from heat induced apoptosis mediated by electromagnetic field exposure.
Robison JG, Pendleton AR, Monson KO, Murray BK, O'Neill KL.
Department of Microbiology, Brigham Young University, Provo, Utah 84602, USA.
In this study, we demonstrate that electromagnetic field (EMF) exposure results in protection from heat induced apoptosis in human cancer cell lines in a time dependent manner. Apoptosis protection was determined by growing HL-60, HL-60R, and Raji cell lines in a 0.15 mT 60 Hz sinusoidal EMF for time periods between 4 and 24 h. After induction of apoptosis, cells were analyzed by the neutral comet assay to determine the percentage of apoptotic cells. To discover the duration of this protection, cells were grown in the EMF for 24 h and then removed for 24 to 48 h before heat shock and neutral comet assays were performed. Our results demonstrate that EMF exposure offers significant protection from apoptosis (P<.0001 for HL-60 and HL-60R, P<.005 for Raji) after 12 h of exposure and that protection can last up to 48 h after removal from the EMF. In this study we further demonstrate the effect of the EMF on DNA repair rates. DNA repair data were gathered by exposing the same cell lines to the EMF for 24 h before damaging the exposed cells and non-exposed cells with H2O2. Cells were allowed to repair for time periods between 0 and 15 min before analysis using the alkaline comet assay. Results showed that EMF exposure significantly decreased DNA repair rates in HL-60 and HL-60R cell lines (P<.001 and P<.01 respectively), but not in the Raji cell line.
Importantly, our apoptosis results show that a minimal time exposure to an EMF is needed before observed effects. This may explain previous studies showing no change in apoptosis susceptibility and repair rates when treatments and EMF exposure were administered concurrently. More research is necessary, however, before data from this in vitro study can be applied to in vivo systems.
Bioelectromagnetics. 2002 Feb;23(2):106-12

7 Effects of static magnetic field on human leukemic cell line HL-60.
Sabo J, Mirossay L, Horovcak L, Sarissky M, Mirossay A, Mojzis J.
Department of Medical Biophysics, Medical Faculty, P.J. Safarik University, Trieda SNP 1, 04011 Kosice, Slovak Republic. grosiar@central.medic.upjs.sk
A number of structures with magnetic moments exists in living organisms that may be oriented by magnetic field. While most experimental efforts belong to the area of effects induced by weak and extremely low-frequency electromagnetic fields, we attempt to give an attention to the biological effects of strong static magnetic fields. The influence of static magnetic field (SMF) on metabolic activity of cells was examined. The metabolic activity retardation is observed in human leukemic cell line HL-60 exposed to 1-T SMF for 72 h. The retardation effect was observed as well as in the presence of the mixture of the antineoplastic drugs 5 fluorouracil, cisplatin, doxorubicin and vincristine.
Bioelectrochemistry
. 2002 May 15;56(1-2):227-31

8 Immunotropic effects of electromagnetic fields in the range of radio- and microwave frequencies
[Article in Polish]
Dabrowski MP, Stankiewicz W, Sobiczewska E, Szmigielski S.
Zaklad Ochrony Mikrofalowej Wojskowego Instytutu Higieny i Epidemiologii w Warszawie.
On the grounds of reviewed literature and the results of own experiments, the authors present current views on the possible immunotropic influence of low energy electromagnetic fields, in the range of radio- and microwave frequencies. They conclude, that a more systematic and multidisciplinary investigations should be undertaken, comprising the wide spectrum of immune homeostatic tasks, including defensive, immunoregulatory and pro-regenerative capabilities of immune system exposed to rapid environmental spread of different electromagnetic emitters.
Pol Merkuriusz Lek. 2001 Nov;11(65):447-51.


9
Study of high- and low-current-configuration homes from the 1988 Denver Childhood Cancer Study.
Kaune WT, Dovan T, Kavet RI, Savitz DA, Neutra RR.
Richland, Washington, USA.
An epidemiological study conducted by Savitz et al. reported that residential wire codes were more strongly associated with childhood cancer than were measured magnetic fields, a peculiar result because wire codes were originally developed to be a surrogate for residential magnetic fields. The primary purpose of the study reported here, known as the Back to Denver (BTD) study, was to obtain data to help in the interpretation of the original results of Savitz et al. The BTD study included 81 homes that had been occupied by case and control subjects of Savitz et al., stratified by wire code as follows: 18 high current configuration (HCC) case homes; 20 HCC control homes; 20 low current configuration (LCC) case homes; and 23 LCC control homes. Analysis of new data acquired in these homes led to the following previously unpublished conclusions. The home-averaged (i.e., mean of fields measured in subjects' bedrooms, family/living rooms, and rooms where meals normally eaten) spot 60 Hz, 180 Hz, and harmonic (i.e., 60-420 Hz) magnetic fields were associated with wire codes. The 180 Hz and harmonic components, but not the 60 Hz component, were associated with case/control status. Measured static magnetic fields were only weakly correlated (approximately 0.2) between rooms in homes. The BTD data provide little support for, but are too sparse to definitively test, the 1995 resonance hypothesis proposed by Bowman et al. Case and control homes had similar concentrations of copper in their tap water. Copper concentration was not associated with wire codes nor with the level of electric current carried by a home's water pipe. These results of the BTD study suggest that future case/control studies investigating power frequency magnetic fields might wish to include measurements of 180 Hz or harmonic magnetic fields in order to examine their associations (if any) with disease status.
Bioelectromagnetics. 2002 Apr;23(3):177-88

10 Exposure to power frequency electric fields and the risk of childhood cancer in the UK.
Skinner J, Mee TJ, Blackwell RP, Maslanyj MP, Simpson J, Allen SG, Day NE, Cheng KK, Gilman E, Williams D, Cartwright R, Craft A, Birch JM, Eden OB, McKinney PA, Deacon J, Peto J, Beral V, Roman E, Elwood P, Alexander FE, Mott M, Chilvers CE, Muir K, Doll R, Taylor CM, Greaves M, Goodhead D, Fry FA, Adams G, Law G; United Kingdom Childhood Cancer Study Investigators.
Strangeways Research Laboratory, University of Cambridge, Wort's Causeway, Cambridge CB1 8RN, UK.
The United Kingdom Childhood Cancer Study, a population-based case-control study covering the whole of Great Britain, incorporated a pilot study measuring electric fields. Measurements were made in the homes of 473 children who were diagnosed with a malignant neoplasm between 1992 and 1996 and who were aged 0-14 at diagnosis, together with 453 controls matched on age, sex and geographical location. Exposure assessments comprised resultant spot measurements in the child's bedroom and the family living-room. Temporal stability of bedroom fields was investigated through continuous logging of the 48-h vertical component at the child's bedside supported by repeat spot measurements. The principal exposure metric used was the mean of the pillow and bed centre measurements. For the 273 cases and 276 controls with fully validated measures, comparing those with a measured electric field exposure >/=20 V m(-1) to those in a reference category of exposure <10 V m(-1), odds ratios of 1.31 (95% confidence interval 0.68-2.54) for acute lymphoblastic leukaemia, 1.32 (95% confidence interval 0.73-2.39) for total leukaemia, 2.12 (95% confidence interval 0.78-5.78) for central nervous system cancers and 1.26 (95% confidence interval 0.77-2.07) for all malignancies were obtained. When considering the 426 cases and 419 controls with no invalid measures, the corresponding odds ratios were 0.86 (95% confidence interval 0.49-1.51) for acute lymphoblastic leukaemia, 0.93 (95% confidence interval 0.56-1.54) for total leukaemia, 1.43 (95% confidence interval 0.68-3.02) for central nervous system cancers and 0.90 (95% confidence interval 0.59-1.35) for all malignancies. With exposure modelled as a continuous variable, odds ratios for an increase in the principal metric of 10 V m(-1) were close to unity for all disease categories, never differing significantly from one.
Br J Cancer
. 2002 Nov 18;87(11):1257-66.

 

11 Childhood cancer in relation to indicators of magnetic fields from ground current sources.
Wertheimer N, Savitz DA, Leeper E.
Department of Epidemiology, University of North Carolina School of Public Health, Chapel Hill, USA.
This study examines childhood cancer risk in relation to certain factors likely to indicate magnetic field exposure from ground currents in the home. Substantial ground currents are most often found in homes having conductive plumbing, in which an uninterrupted metallic path in the water pipes and water main connects the grounding systems of neighbouring houses. Information on plumbing conductivity was obtained from water suppliers for the homes of 347 cases and 277 controls identified in an earlier study of magnetic field exposure and childhood cancer in the Denver area. An increased cancer risk was observed for children in homes with conductive plumbing: the matched odds ratio was 1.72 (1.03-2.88) and increased to 3.00 (1.33-6.76) when analysis was limited to cases and controls who were residentially stable from the reference date to the study date. A measurement metric likely to indicate active ground currents (measurements having above-median intensity and a non-vertical orientation of < 55 degrees from the horizontal) was identified. In contrast to measured field intensity alone, for which only modest associations with cancer have been reported, this metric shows a high and significant cancer risk [matched O.R. = 4.0 (1.6-10.0)] consistent over a range of intensity and angle cutpoints. Such elevated nonvertical fields were also associated with cancer in an independent data set, which was gathered to study adult nonlymphocytic leukemia in the Seattle area. The associations of cancer with conductive plumbing and with this exposure metric both suggest that cancer risk is increased among persons with elevated magnetic field exposure from residential ground currents.

Bioelectromagnetics. 1995;16(2):86-96

12
Electromagnetic field exposures and childhood cancers in New Zealand.
Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand.
OBJECTIVES: To assess childhood cancer risks for electromagnetic field (EMF) exposures. METHODS: A case-control study was conducted in New Zealand. Cases (aged from zero to 14 years) were ascertained from national databases including the New Zealand Cancer Registry; 303 took part (participation rate, 88 percent). The 303 age- and gender-matched controls were selected randomly from birth records (participation, 69 percent). Mothers were interviewed about appliance exposures (all cases and controls), and 24-hour residential measurements of EMFs were made (leukemia cases and matched controls). RESULTS: For the various appliance exposures, there were some odds ratios (OR) above 1.0 and others below 1.0. For electric blanket use by the child before diagnosis, the adjusted ORs were: leukemia, 2.2 (95 percent confidence interval [CI] = 0.7-6.4); central nervous system cancers, ORs = 1.6 (CI = 0.4-7.1); and other solid cancers, OR = 2.4 (CI = 1.0-6.1). Leukemia risk was increased for the highest category of the mean measured bedroom magnetic field (> or = 0.2microT cf < 0.1 microT), with an adjusted OR of 15.5 (CI = 1.1-224). A gradient in OR with exposure was not shown (middle category: OR 1.4, CI = 0.3-7.6), and there was no association with exposure categorized into thirds based on controls' exposure. The adjusted OR for leukemia in relation to the measured daytime room magnetic field (> or = 0.2 microT cf < 0.1 microT) was 5.2 (CI = 0.9-30.8). CONCLUSIONS: This was a small study and multiple comparisons were made. The positive findings thus should be interpreted cautiously.

Cancer Causes Control. 1998 May;9(3):299-309.

Association between magnetic fields and childhood leukemia.
13 Exposure to residential electric and magnetic fields and risk of childhood leukemia.
London SJ, Thomas DC, Bowman JD, Sobel E, Cheng TC, Peters JM.
Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles.
The relation between exposure to electric and magnetic fields in the home, as assessed by measurements, wiring configuration, and self-reported appliance use, and risk of leukemia was investigated in a case-control study among children from birth to age 10 years in Los Angeles County, California. Cases were ascertained through a population-based tumor registry from 1980 to 1987. Controls were drawn from friends and by random digit dialing. Interviews were obtained from 232 cases and 232 controls. Available for analysis were measurements of the magnetic field in the child's bedroom over 24 hours or longer (164 cases and 144 controls), spot measurements of magnetic and electric fields (140 cases and 109 controls), and wiring configuration (219 cases and 207 controls). No clear associations between leukemia risk and measured magnetic or electric fields were seen. An association between the Denver Wertheimer-Leeper wiring configuration and childhood leukemia risk was observed (odds ratio for very high relative to very low current and underground configuration combined = 2.15, 95% confidence interval 1.08-4.28; p for trend = 0.008) and was not substantially altered by adjustment for potential confounding factors. Cases were more likely than controls to report use of several appliances that produce high electric and magnetic fields. Our results support an association between childhood leukemia risk and wiring configuration, but not direct measurements of electric and magnetic fields.
Am J Epidemiol. 1991 Nov 1;134(9):923-37

14 Hypothesis: the risk of childhood leukemia is related to combinations of power-frequency and static magnetic fields.
Bowman JD, Thomas DC, London SJ, Peters JM.
Department of Preventive Medicine, University of Southern California, Los Angeles, USA.
We present a hypothesis that the risk of childhood leukemia is related to exposure to specific combinations of static and extremely-low-frequency (ELF) magnetic fields. Laboratory data from calcium efflux and diatom mobility experiments were used with the gyromagnetic equation to predict combinations of 60 Hz and static magnetic fields hypothesized to enhance leukemia risk. The laboratory data predicted 19 bands of the static field magnitude with a bandwidth of 9.1 microT that, together with 60 Hz magnetic fields, are expected to have biological activity. We then assessed the association between this exposure metric and childhood leukemia using data from a case-control study in Los Angeles County. ELF and static magnetic fields were measured in the bedrooms of 124 cases determined from a tumor registry and 99 controls drawn from friends and random digit dialing. Among these subjects, 26 cases and 20 controls were exposed to static magnetic fields lying in the predicted bands of biological activity centered at 38.0 microT and 50.6 microT. Although no association was found for childhood leukemia in relation to measured ELF or static magnetic fields alone, an increasing trend of leukemia risk with measured ELF fields was found for subjects within these static field bands (P for trend = 0.041). The odds ratio (OR) was 3.3 [95% confidence interval (CI) = 0.4-30.5] for subjects exposed to static fields within the derived bands and to ELF magnetic field above 0.30 microT (compared to subjects exposed to static fields outside the bands and ELF magnetic fields below 0.07 microT). When the 60 Hz magnetic fields were assessed according to the Wertheimer-Leeper code for wiring configurations, leukemia risks were again greater with the hypothesized exposure conditions (OR = 9.2 for very high current configurations within the static field bands; 95% CI = 1.3-64.6). Although the risk estimates are based on limited magnetic field measurements for a small number of subjects, these findings suggest that the risk of childhood leukemia may be related to the combined effects of the static and ELF magnetic fields. Further tests of the hypothesis are proposed.

Bioelectromagnetics. 1995;16(1):48-59

15 Combined risk estimates for two German population-based case-control studies on residential magnetic fields and childhood acute leukemia.
Michaelis J, Schuz J, Meinert R, Zemann E, Grigat JP, Kaatsch P, Kaletsch U, Miesner A, Brinkmann K, Kalkner W, Karner H.
Institut fur Medizinische Statistik und Dokumentation, Johannes Gutenberg-University of Mainz, Germany.
From 1992 to 1996, we obtained electromagnetic field measurements in two population-based case-control studies on childhood leukemia in the northwestern part of Germany and in Berlin. Exposure assessment comprised residential 24-hour measurements and short-term measurements. We obtained 24-hour measurements for a total of 176 cases and 414 controls. We compared subjects exposed to median 24-hour measurements of 0.2 microT or more with those exposed to lower amounts. Multivariate regression analysis revealed an odds ratio of 2.3 (95% confidence interval = 0.8-6.7).

Epidemiology. 1998 Jan;9(1):92-4.
 
16 [Synthesis of the epidemiological evidence concerning childhood leukemia in relation to exposure to 50 Hz. electric and magnetic fields]

Lagorio S, Comba P.
Istituto Superiore di Sanita, Roma.
A review of epidemiologic evidence concerning the association between childhood leukaemia and exposure to 50 Hz electric and magnetic fields is presented, with special reference to fourteen studies published between 1979 and 1997 that utilised different systems of exposure assessment. While spot measurements of indoor magnetic fields were not associated with childhood leukaemia, combined relative risks from studies using 24 hour measurements range from 1.3 to 1.6 with lower confidence limits > or = 1.0. Thus, epidemiologic studies support an association between exposure to 50 Hz magnetic fields and childhood leukaemia. However, the causal nature of the association does not appear conclusively demonstrated because of limitations in study design and lack of a plausible biologic mechanism. In this framework, it seems justified to recommend the adoption of preventive measures aimed at reducing exposure to magnetic fields in dwellings, particularly in those featuring relatively high exposure levels.
Med Lav
.
1998 Mar-Apr;89(2):132-41

17 Power-frequency electric and magnetic fields and risk of childhood leukemia in Canada.
McBride ML, Gallagher RP, Theriault G, Armstrong BG, Tamaro S, Spinelli JJ, Deadman JE, Fincham S, Robson D, Choi W.
Cancer Control Research Programme, British Columbia Cancer Agency, Vancouver, Canada.
In a case-control study of childhood leukemia in relation to exposure to power-frequency electric and magnetic fields (EMF), 399 children resident in five Canadian provinces who were diagnosed at ages 0-14 years between 1990 and 1994 (June 1995 in British Columbia and Quebec) were enrolled, along with 399 controls. Exposure assessment included
48-hour personal EMF measurement, wire coding and magnetic field measurements for subjects' residences from conception to diagnosis/reference date, and a 24-hour magnetic field bedroom measurement. Personal magnetic fields were not related to risk of leukemia (adjusted odds ratio (OR) = 0.95, p for trend = 0.73) or acute lymphatic leukemia (OR = 0.93, p for trend = 0.64). There were no clear associations with predicted magnetic field exposure 2 years before the diagnosis/reference date or over the subject's lifetime or with personal electric field exposure. A statistically nonsignificant elevated risk of acute lymphatic leukemia was observed with very high wiring configurations among residences of subjects 2 years before the diagnosis/reference date (OR = 1.72 compared with underground wiring, 95% confidence interval 0.54-5.45). These results provide little support for a relation between power-frequency EMF exposure and risk of childhood leukemia.
Am J Epidemiol.
1999 May 1;149(9):831-42

18 Childhood leukemia and personal monitoring of residential exposures to electric and magnetic fields in Ontario, Canada.
Green LM, Miller AB, Agnew DA, Greenberg ML, Li J, Villeneuve PJ, Tibshirani R.

Department of Public Health Sciences, University of Toronto, Ontario, Canada.
OBJECTIVES: To evaluate the risk of childhood leukemia in relation to residential electric and magnetic field (EMF) exposures. METHODS: A case control study based on 88 cases and 133 controls used different assessment methods to determine EMF exposure in the child's current residence. Cases comprised incident leukemias diagnosed at 0-14 years of age between 1985-1993 from a larger study in southern Ontario; population controls were individually matched to the cases by age and sex. Exposure was measured by a personal monitoring device worn by the child during usual activities at home, by point-in-time measurements in three rooms and according to wire code assigned to the child's residence. RESULTS: An association between magnetic field exposures as measured with the personal monitor and increased risk of leukemia was observed. The risk was more pronounced for those children diagnosed at less than 6 years of age and those with acute lymphoblastic leukemia. Risk estimates associated with magnetic fields tended to increase after adjusting for power consumption and potential confounders with significant odds ratios (OR) (OR: 4.5, 95% confidence interval (CI): 1.3-15.9) observed for exposures > or = 0.14 microTesla (microT). For the most part point-in-time measurements of magnetic fields were associated with non-significant elevations in risk which were generally compatible with previous research. Residential proximity to power lines having a high current configuration was not associated with increased risk of leukemia. Exposures to electric fields as measured by personal monitoring were associated with a decreased leukemia risk. CONCLUSIONS: The findings relating to magnetic field exposures directly measured by personal monitoring support an association with the risk of childhood leukemia. As exposure assessment is refined, the possible role of magnetic fields in the etiology of childhood leukemia becomes more evident.

Cancer Causes Control. 1999 Jun;10(3):233-43.

19 A case-control study of childhood leukemia in southern Ontario, Canada, and exposure to magnetic fields in residences.
Green LM, Miller AB, Villeneuve PJ, Agnew DA, Greenberg ML, Li J, Donnelly KE.
Department of Public Health Sciences, University of Toronto, Canada. lm.green@utoronto.ca
A population-based case-control study was conducted in Ontario, Canada, to assess the relation between the risk of childhood leukemia and residential exposure to magnetic fields. Participating subjects consisted of 201 cases, diagnosed at 0 to 14 years of age during 1985-1993, ascertained from the records at the Hospital for Sick Children (Toronto), and 406 individually matched controls. Where possible, point-in-time measurements of magnetic fields were made in all residences occupied by subjects during the period of inquiry in the defined catchment area. Three different classification schemes of wire code were assigned to each residence. Detailed information was collected by interviewer-administered questionnaires, which enabled risk estimates to be adjusted for socio-economic characteristics, medical history of parent(s) and child and environmental exposures. Inconsistent elevations in risk were associated with time-weighted averages of magnetic fields both inside and outside the home for subjects having residential point-in-time measurements that represented at least 70% of their etiological period. These risks increased in magnitude when analysis was restricted to children under 6 years of age at diagnosis or to those with acute lymphoblastic leukemia. For children younger than 6 years at diagnosis, outside perimeter measurements of the residence, > or = 0.15 microT, were associated with increased leukemia risk (OR = 3.45, 95% CI = 1.14-10.45). Evaluation of different exposure times for point-in-time magnetic field measurements and wire configuration suggested that exposures earliest in the etiological period were associated with greater risks for children diagnosed at a younger age (OR = 2.50, 95% CI = 1.14-5.49). Our findings did not support an association between leukemia and proximity to power lines with high current configuration.
Int J Cancer.
1999 Jul 19;82(2):161-70.

20 Residential magnetic fields predicted from wiring configurations: II. Relationships To childhood leukemia.
Thomas DC, Bowman JD, Jiang L, Jiang F, Peters JM.
Department of Preventive Medicine, University of Southern California, Los Angeles, California.
Case-control data on childhood leukemia in Los Angeles County were reanalyzed with residential magnetic fields predicted from the wiring configurations of nearby transmission and distribution lines. As described in a companion paper, the 24-h means of the magnetic field's magnitude in subjects' homes were predicted by a physically based regression model that had been fitted to 24-h measurements and wiring data.
In addition, magnetic field exposures were adjusted for the most likely form of exposure assessment errors: classic errors for the 24-h measurements and Berkson errors for the predictions from wire configurations. Although the measured fields had no association with childhood leukemia (P for trend=.88), the risks were significant for predicted magnetic fields above 1.25 mG (odds ratio=2.00, 95% confidence interval=1.03-3.89), and a significant dose-response was seen (P for trend=.02). When exposures were determined by a combination of predictions and measurements that corrects for errors, the odds ratio (odd ratio=2.19, 95% confidence interval=1.12-4.31) and the trend (p =.007) showed somewhat greater significance. These findings support the hypothesis that magnetic fields from electrical lines are causally related to childhood leukemia but that this association has been inconsistent among epidemiologic studies due to different types of exposure assessment error. In these data, the leukemia risks from a child's residential magnetic field exposure appears to be better assessed by wire configurations than by 24-h area measurements. However, the predicted fields only partially account for the effect of the Wertheimer-Leeper wire code in a multivariate analysis and do not completely explain why these wire codes have been so often associated with childhood leukemia. The most plausible explanation for our findings is that the causal factor is another magnetic field exposure metric correlated to both wire code and the field's time-averaged magnitude. Bioelectromagnetics. 1999 Oct;20(7):414-22

21 A pooled analysis of magnetic fields and childhood leukaemia.
Ahlbom A, Day N, Feychting M, Roman E, Skinner J, Dockerty J, Linet M, McBride M, Michaelis J, Olsen JH, Tynes T, Verkasalo PK.
Division of Epidemiology, National Institute of Environmental Medicine, Karolinska Institute, Sweden.
Previous studies have suggested an association between exposure to 50-60 Hz magnetic fields (EMF) and childhood leukaemia. We conducted a pooled analysis based on individual records from nine studies, including the most recent ones. Studies with 24/48-hour magnetic field measurements or calculated magnetic fields were included. We specified which data analyses we planned to do and how to do them before we commenced the work. The use of individual records allowed us to use the same exposure definitions, and the large numbers of subjects enabled more precise estimation of risks at high exposure levels. For the 3203 children with leukaemia and 10 338 control children with estimated residential magnetic field exposures levels < 0.4 microT, we observed risk estimates near the no effect level, while for the 44 children with leukaemia and 62 control children with estimated residential magnetic field exposures >/= 0.4 microT the estimated summary relative risk was 2.00 (1.27-3.13), P value = 0.002). Adjustment for potential confounding variables did not appreciably change the results. For North American subjects whose residences were in the highest wire code category, the estimated summary relative risk was 1.24 (0.82-1.87). Thus, we found no evidence in the combined data for the existence of the so-called wire-code paradox. In summary, the 99.2% of children residing in homes with exposure levels < 0.4 microT had estimates compatible with no increased risk, while the 0.8% of children with exposures >/= 0.4 microT had a relative risk estimate of approximately 2, which is unlikely to be due to random variability. The explanation for the elevated risk is unknown, but selection bias may have accounted for some of the increase.

Br J Cancer. 2000 Sep;83(5):692-8.

22 [Infantile leukemia and exposure to 50/60 Hz magnetic fields: review of epidemiologic evidence in 2000] [Article in Italian]
Lagorio S, Salvan A.
Laboratorio di Igiene Ambientale, Istituto Superiore di Sanita, Roma.
We review the epidemiological evidence on childhood leukemia and residential exposure to 50/60 Hz magnetic fields. The possibility of carcinogenic effects of power frequency magnetic fields (ELF-EMF), at levels below units of micro tesla (microT), was first raised in 1979 by a case-control study on childhood cancer carried out in Denver, USA. In that study, excess risks of total cancer and leukemia were observed among children living in homes with "high or very high current configuration", as categorised on the basis of proximity to electric lines and transformers.
Many other epidemiological studies have been published since then, characterised by improved--although still not optimal--methods of exposure assessment.
At the end of 2000, the epidemiological evidence to support the association between exposure to extremely-low-frequency magnetic fields and the risk of childhood leukemia is less consistent than what was observed in the mid 90s. At the same time, a growing body of experimental evidence has accumulated against both a direct and a promoting carcinogenic effect of ELF-EMF. Such "negative" experimental evidence hampers a causal interpretation of the "positive" epidemiological studies.
Ann Ist Super Sanita. 2001;37(2):213-24.

23 Residential magnetic fields as a risk factor for childhood acute leukaemia: results from a German population-based case-control study.
Schuz J, Grigat JP, Brinkmann K, Michaelis J.
Institute for Medical Statistics and Documentation, University of Mainz, Mainz, Germany. schuez@imsd.uni-mainz.de
Our objective was to investigate whether exposure to residential power-frequency (50 Hz) magnetic fields above 0.2 microT increases a child's risk of leukaemia and to confirm or reject a finding from a previous German study on this topic, which reported increased leukaemia risk with exposure to stronger magnetic fields during the night. A population-based case-control study was used, covering the whole of the former West Germany. Residential magnetic fields were measured over 24 hr for 514 children with acute leukaemia identified by the German Childhood Cancer Registry and 1,301 control children taken from population registration files. Magnetic fields above 0.2 microT were relatively rare in Germany (only 1.5% of the study population). Childhood leukaemia and 24 hr median magnetic fields were only weakly related (OR = 1.55, 95% CI 0.65-3.67). A significant association was seen between childhood leukaemia and magnetic field exposure during the night (OR = 3.21, 95% CI 1.33-7.80).
A dose-response-relationship was observed after combining the data of all German studies on magnetic fields and childhood leukaemia.
The evidence for an association between childhood leukaemia and magnetic field exposure in our study comes from a measure of exposure during the night. Despite the large size of our study, the results are based on small numbers of exposed children. If the observed association stands, the effect on a population level in Germany would be small. Int J Cancer. 2001 Mar 1;91(5):728-35


24 The potential impact of bias in studies of residential exposure to magnetic fields and childhood leukemia.
Wartenberg D.
Environmental and Occupational Health Sciences Institute, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA. dew@eohsi.rutgers.edu
Bias can have a major impact on the results of epidemiologic studies. In investigations of the possible association between residential exposure to magnetic fields and the occurrence of childhood leukemia, many have raised questions about selection bias, including participation bias and information bias. In this review, the data on these possible sources of bias are summarized and their likely impact is evaluated. Most data suggest that if a bias exists, it is a bias towards the lack of association between exposure to magnetic fields and childhood leukemia. In addition, given the wide variety of study populations and measurement protocols, it is unlikely that a single design flaw has resulted in consistent effects across all studies and can be the sole explanation for the reported associations.
Bioelectromagnetics. 2001;Suppl 5:S32-47

25 Residential EMF exposure and childhood leukemia: meta-analysis and population attributable risk.
Wartenberg D.
Environmental and Occupational Health Sciences Institute, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08855, USA. dew@eohsi.rutgers.edu
The controversy over the possible association between magnetic field exposure and childhood leukemia has led several researchers to summarize the literature using meta-analysis. This paper reviews these previous meta-analyses and extends them by adding results from four studies published since the most recent analysis. The analyses include odds ratio calculations based on both dichotomous and continuous exposure models, heterogeneity analysis including subgroup summaries and meta-regression, "leave one out" influence analyses, and publication bias assessments. In addition, there is a review of some of the considerations of the exposure assessments used in the studies and their implications for cross-study comparisons. Finally, the results of the analyses using dichotomous and continuous exposure model are combined with national exposure data to estimate the population attributable risk of childhood leukemia among children in the US. If an association exists, as many as 175-240 cases of childhood leukemia in the US may be due to magnetic field exposure.
Bioelectromagnetics.
2001;Suppl 5:S86-104.

26 Do studies of wire code and childhood leukemia point towards or away from magnetic fields as the causal agent?
Savitz DA, Poole C.
Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill 27599, USA. david_savitz@unc.edu
A long-standing point of controversy in the epidemiologic literature concerns the meaning of a wire code-childhood leukemia association for assessing the role of magnetic field exposure. Six studies of wire codes and childhood leukemia in North America were examined, three of which reported positive associations and all of which found some relation between wire codes and measured magnetic fields. Supporting magnetic fields as the basis for the wire code associations are the correspondence between those wire code levels which predict distinct magnetic fields and those which predict leukemia risk in the positive studies. Geographic locations and methods that refine wire codes as magnetic fields predictors also tend to strengthen the association with leukemia. Opposing arguments are based on the failure of the wire code-magnetic field association to predict the strength of association across studies, including the unexplained lack of association between wire codes and leukemia in the Midwest and in Canada. Alternatives to magnetic fields are less supported; residential mobility, social class, and neighbourhood characteristics are unlikely to explain a wire code effect. Ambiguity persists because of the modest strength of the wire code-leukemia association, the complexity of the relation between wire codes and magnetic fields, lack of knowledge of risk factors for childhood leukemia, and the limited evaluation of wire code correlates other than magnetic fields.  
Bioelectromagnetics. 2001;Suppl 5:S69-85

27 Factors that explain the power line configuration wiring code-childhood leukemia association: what would they look like?
Langholz B.
Department of Preventive Medicine, University of Southern California, School of Medicine, Los Angeles 90089-9011, USA. langholz@hsc.usc.edu
We explore the question of how to characterize a factor that would explain the patterns of wire code-childhood leukemia association observed in three major United States case-control studies. In positive studies, such a factor needs to be more prevalent in "high" wire codes than "low" whereas in negative studies, the factor should not be correlated to wire code. These concepts are quantified and we use these results to characterize potential factors that might explain the wire code-childhood leukemia association. We then re-evaluate findings from a survey of correlates of wire code in Connecticut with respect to potential for explaining the wire code-leukemia association. Under the presumption that the Connecticut correlations apply to the populations in which a wire code-leukemia association has been observed, only age and type of home are correlated enough to be potential explanatory factors. In particular, it appears very unlikely that traffic density can explain a significant portion of the wire code association. We suggest that correlation studies can be useful for identifying potential explanatory factors, but they must be done in regions where a wire code-childhood leukemia association has been observed.
Bioelectromagnetics.
2001;Suppl 5:S19-31

28 Leukemia mortality and incidence of infantile leukemia near the Vatican Radio Station of Rome
Michelozzi P, Kirchmayer U, Capon A, Forastiere F, Biggeri A, Barca A, Ancona C, Fusco D, Sperati A, Papini P, Pierangelini A, Rondelli R, Perucci CA.
Dipartimento di epidemiologia ASL RM/E, Roma. salute@asplazio.it
Some recent epidemiological studies suggest an association between lymphatic and haematopoietic cancers and residential exposure to high frequency electromagnetic fields (100 kHz-300 GHz) generated by radio and television transmitters. Vatican Radio, a very powerful radio station transmitting all over the world (up to 600 kW) is located in Santa Maria di Galeria, in the northern suburbs of the city of Rome. Electric field measurements in the proximity of the radio station ranged between 1.5 and 25 V/m.
In the 10 km area around the station, with 60.182 residents (1999), leukaemia mortality among adults (> 14 years, 40 cases) in the period 1987-98 and childhood leukaemia incidence in the period 1987-99 (8 cases) were evaluated. The analysis (Stone's conditional test) was performed computing observed and expected cases (reference: population of Rome) in 5 bands of increasing radius (2 km width). The risk of childhood leukaemia was higher than expected within 6 km from the station (Standardized Incidence Ratio = 217; 95% Confidence Interval 99-405). Stone's test showed a significant decrease in risk with increasing distance both for male adult mortality (p-value = 0.03) and for childhood incidence (p-value = 0.04). A Score test, showed a significant decrease in risk of childhood incidence as function of the distance. The main limitations of this study are the small number of observed cases and the use of distance as a proxy for RF exposure. Further research will require a systematic campaign of electromagnetic field measurements to allow better assessment of the population exposure.
Epidemiol Prev. 2001 Nov-Dec;25(6):249-55.

29 Adult and childhood leukemia near a high-power radio station in Rome, Italy.
Michelozzi P, Capon A, Kirchmayer U, Forastiere F, Biggeri A, Barca A, Perucci CA.
Department of Epidemiology, Local Health Authority RME, Rome, Italy. salute@asplazio.it
Some recent epidemiologic studies suggest an association between lymphatic and hematopoietic cancers and residential exposure to high-frequency electromagnetic fields (100 kHz to 300 GHz) generated by radio and television transmitters. Vatican Radio is a very powerful station located in a northern suburb of Rome, Italy.
In the 10-km area around the station, with 49.656 residents (in 1991), leukemia mortality among adults (aged >14 years; 40 cases) in 1987-1998 and childhood leukemia incidence (eight cases) in 1987-1999 were evaluated.
The risk of childhood leukemia was higher than expected for the distance up to 6 km from the radio station (standardized incidence rate = 2.2, 95% confidence interval: 1.0, 4.1), and there was a significant decline in risk with increasing distance both for male mortality (p = 0.03) and for childhood leukemia (p = 0.036).
The study has limitations because of the small number of cases and the lack of exposure data. Although the study adds evidence of an excess of leukemia in a population living near high-power radio transmitters, no causal implication can be drawn. There is still insufficient scientific knowledge, and new epidemiologic studies are needed to clarify a possible leukemogenic effect of residential exposure to radio frequency radiation.

Am J Epidemiol. 2002 Jun 15;155(12):1096-103.

30 Childhood leukemia and magnetic fields in infant incubators.
Soderberg KC, Naumburg E, Anger G, Cnattingius S, Ekbom A, Feychting M.
Institute of Environmental Medicine, Karolinska Institutet, Institute, Stockholm, Sweden. Karin.Soderberg@imm.ki.se
In studies of magnetic field exposure and childhood leukemia, power lines and other electrical installations close to the children's homes constitute the most extensively studied source of exposure. We conducted a study to assess whether exposure to magnetic fields in infant incubators is associated with an increased leukemia risk. We identified all children with leukemia born in Sweden between 1973 and 1989 from the national Cancer Registry and selected at random one control per case, individually matched by sex and time of birth, from the study base. We retrieved information about treatment in infant incubators from medical records. We made measurements of the magnetic fields inside the incubators for each incubator model kept by the hospitals. Exposure assessment was based on measurements of the magnetic field level inside the incubator, as well as on the length of treatment. For acute lymphoblastic leukemia, the risk estimates were close to unity for all exposure definitions. For acute myeloid leukemia, we found a slightly elevated risk, but with wide confidence intervals and with no indication of dose response. Overall, our results give little evidence that exposure to magnetic fields inside infant incubators is associated with an increased risk of childhood leukemia.
Epidemiology. 2002 Jan;13(1):45-9

31 Potential motion related bias in the worn dosimeter measurements of two childhood leukemia studies.
Leeper E, Wertheimer N.
Monitor Industries, Boulder, CO 80302, USA. edleeper@mymailstation.com
Time averaged field measurements produced by a Positron dosimeter worn by study subjects was the primary method of exposure evaluation in two Canadian studies of childhood leukemia and AC magnetic field exposure. Statistically significant but mutually contradictory results obtained in the two studies, done in different locales but under similar study conditions, have not been explained. This report examines operational features of the Positron meter, including an unanticipated sensitivity to wearer motion. If the convalescent cases studied were less active than their healthy controls, as one might expect, then the meter's characteristic responses to motion, particularly as they would affect case-control distributions above and below the different referent group cutpoints used in the two studies, could help to explain both the unexpected inverse risks reported in the larger study and the unusually high risks reported in the smaller study. Copyright 2002 Wiley-Liss, Inc.
Bioelectromagnetics. 2002 Jul;23(5):390-7

 

32 Contact voltage measured in residences: implications to the association between magnetic fields and childhood leukemia.
Kavet R, Zaffanella LE.
Environment Department, EPRI, Palo Alto, California 94303, USA. rkavet@epri.com
We measured magnetic fields and two sources of contact current in 36 homes in Pittsfield, MA.
The first source, V(P-W), is the voltage due to current in the grounding wire, which extends from the service panel neutral to the water service line. This voltage can cause contact current to flow upon simultaneous contact with a metallic part of the water system, such as the faucet, and the frame of an appliance, which is connected to the panel neutral through the equipment-grounding conductor.
The second is V(W-E), the voltage between the water pipe and earth, attributable to ground currents in the water system and magnetic induction from nearby power lines. In homes with conductive water systems and drains, V(W-E) can produce a voltage between the faucet and drain, which may produce contact current into an individual contacting the faucet while immersed in a bathtub. V(P-W) was not strongly correlated to the magnetic field (both log transformed) (r = 0.28; P < 0.1). On the other hand, V(W-E) was correlated to the residential magnetic field (both log transformed) (r = 0.54; P < 0.001), with the highest voltages occurring in homes near high voltage transmission lines, most likely due to magnetic induction on the grounding system.
This correlation, combined with both frequent exposure opportunity for bathing children and substantial dose to bone marrow resulting from contact, lead us to suggest that contact current due to V(W-E) could explain the association between high residential magnetic fields and childhood leukemia.
Bioelectromagnetics. 2002 Sep;23(6):464-74

33 Correlation of year-to-year magnetic field exposure metrics among children in a leukemia survival study.
Foliart DE, Iriye RN, Silva JM, Mezei G, Tarr KJ, Ebi KL.
Public Health Institute, Berkeley, California, USA. dfoliart@aol.com
The Childhood Leukemia Survival Study is examining the possible association between magnetic field exposure and survival of children with newly diagnosed acute lymphocytic leukemia (ALL). We report the results of serial 24-h personal magnetic field monitoring for 412 US and Canadian children and present the correlations between annual values. The mean time-weighted average (TWA) and geometric mean (GM) were similar for first, second, and third year measurements [TWA: 0.11 microT (n = 412), 0.13 microT (n = 304), and 0.12 microT (n = 134), respectively]. There were no consistent differences in mean TWA or GM based on age or gender. Significantly lower mean TWA and GM were found for children living in rural areas. Higher exposures were noted among children living in urban areas, among apartments dwellers, and those living in rental homes. Measurements taken during summer months and among children residing in the northeast and Canada also tended to be higher. Correlations for most metrics were increased among children who had annual measurements performed during the same season. The metric with the highest year-to-year correlation was the GM. The lowest correlations were found for metrics estimating field intermittency and temporal stability. First to second year GMs were well correlated when taken in the same home (Spearman rank correlation = 0.70), but a lower correlation (0.44) was noted among residentially mobile children. Our findings suggest that summarizing exposure using a single measurement of GM can estimate exposures for residentially stable children, but is not a good predictor of personal exposures among children
J Expo Anal Environ Epidemiol. 2002 Nov;12(6):441-7

34 Interactive effect of chemical substances and occupational electromagnetic field exposure on the risk of gliomas and meningiomas in Swedish men.
Navas-Acien A, Pollan M, Gustavsson P, Floderus B, Plato N, Dosemeci M.
Environmental and Cancer Epidemiology Area, National Center for Epidemiology, Carlos III Institute of Health, 28029 Madrid, Spain.
The objective of our study was to investigate the possible interactive effect of occupational exposure to extremely low-frequency magnetic field (ELFMF) and to known or suspected carcinogenic chemicals on the incidence of the two main histological types of brain cancer, gliomas and meningiomas, in a cohort of male Swedish workers.
The historical cohort of all Swedish men gainfully employed in 1970 were followed 19 years (1971-1989). Exposure to ELFMF and to nine chemicals were assessed using two Swedish job exposure matrices based on occupational codes and industrial activity. Relative risks adjusted for age, period, geographical area, and town size were computed using log-linear Poisson models. The main finding was the absence of ELFMF effect on glioma risk in the absence of a simultaneous exposure to chemical products. The effect of petroleum products was independent of the intensity of ELFMF exposure whereas solvents, lead, and pesticides/herbicides were only associated with glioma in workers also exposed to moderate or high levels of ELFMF. On the other hand, whereas ELFMF seemed to enhance the effect of specific chemicals in the causation of gliomas, we did not find a relationship between ELFMF exposure and meningiomas. The potential for ELFMF to act as an effect modifier of the association of chemical agents and glioma is an interesting new finding. It would be worthwhile to evaluate this hypothesis for other tumors. Also, it is necessary to confirm these results in epidemiological studies with individual exposure assessments, and in experimental studies that may elucidate whether there is a true causal mechanism for the results we observed.
Cancer Epidemiol Biomarkers Prev.
2002 Dec;11(12):1678-83.

35
Epidemiology of primary brain tumors: current concepts and review of the literature.
Wrensch M, Minn Y, Chew T, Bondy M, Berger MS.
Department of Epidemiology and Biostatistics University of California at San Francisco, San Francisco, CA 94143, USA.
The purpose of this review is to provide a sufficiently detailed perspective on epidemiologic studies of primary brain tumors to encourage multidisciplinary etiologic and prognostic studies among surgeons, neuro-oncologists, epidemiologists, and molecular scientists. Molecular tumor markers that predict survival and treatment response are being identified with hope of even greater gains in this area from emerging array technologies. Regarding risk factors, studies of inherited susceptibility and constitutive polymorphisms in genes pertinent to carcinogenesis (for example, DNA repair and detoxification genes and mutagen sensitivity) have revealed provocative findings. Inverse associations of the history of allergies with glioma risk observed in 3 large studies and reports of inverse associations of glioma with common infections suggest a possible role of immune factors in glioma genesis or progression. Studies continue to suggest that brain tumors might result from workplace, dietary, and other personal and residential exposures, but studies of cell phone use and power frequency electromagnetic fields have found little to support a causal connection with brain tumors; caveats remain. The only proven causes of brain tumors (that is, rare hereditary syndromes, therapeutic radiation, and immune suppression giving rise to brain lymphomas) account for a small proportion of cases. Progress in understanding primary brain tumors might result from studies of well-defined histologic and molecular tumor types incorporating assessment of potentially relevant information on subject susceptibility and environmental and noninherited endogenous factors (viruses, radiation, and carcinogenic or protective chemical exposures through diet, workplace, oxidative metabolism, or other sources). Such studies will require the cooperation of researchers from many disciplines.
Neuro-oncol. 2002 Oct;4(4):278-99.

36
Electromagnetic fields and breast cancer on long island: a case-control study.
Schoenfeld ER, O'Leary ES, Henderson K, Grimson R, Kabat GC, Ahnn S, Kaune WT, Gammon MD, Leske MC.
Department of Preventive Medicine, School of Medicine, Stony Brook University, Stony Brook, NY.
The EMF and Breast Cancer on Long Island Study (EBCLIS) was a case-control study designed to evaluate the possible association between exposure to electromagnetic fields (EMFs) and breast cancer. Eligible women were participants in the population-based Long Island Breast Cancer Study Project, were under 75 years of age at enrollment, were residentially stable, and were identified between August 1, 1996, and June 20, 1997. Of those eligible, 576 cases and 585 controls participated in EBCLIS (87% and 83%, respectively). In-home data collection included various spot and 24-hour EMF measurements, ground-current magnetic field measurements, wire mapping of overhead power lines servicing the home, and an interview. Odds ratios and 95% confidence intervals were based on multivariate logistic regression analyses. All odds ratios were close to 1 and nonsignificant. For the highest quartile of 24-hour EMF measurements, the odds ratio was 0.97 (95% confidence interval (CI): 0.69, 1.37) in the bedroom and 1.09 (95% CI: 0.78, 1.51) in the most lived-in room. For the highest exposure category of ground-current measurements, the odds ratio was 1.13 (95% CI: 0.88, 1.44) in the bedroom and 1.08 (95% CI: 0.85, 1.38) in the most lived-in room. These and other EBCLIS results agree with other recent reports of no association between breast cancer and residential EMF exposures.
Am J Epidemiol.
2003 Jul 1;158(1):47-58.

Interaction of static and extremely low frequency electric and magnetic fields with living systems: health effects and research needs.
Repacholi MH, Greenebaum B.
World Health Organization, Geneva, Switzerland. repacholim@who.ch
An international seminar was held June 4-6, 1997, on the biological effects and related health hazards of ambient or environmental static and extremely low frequency (ELF) electric and magnetic fields (0-300 Hz). It was cosponsored by the World Health Organization (WHO), the International Commission on Non-Ionizing Radiation Protection (ICNIRP), the German, Japanese, and Swiss governments. Speakers provided overviews of the scientific literature that were discussed by participants of the meeting. Subsequently, expert working groups formulated this report, which evaluates possible health effects from exposure to static and ELF electric and magnetic fields and identifies gaps in knowledge requiring more research to improve health risk assessments. The working groups concluded that, although health hazards exist from exposure to ELF fields at high field strengths, the literature does not establish that health hazards are associated with exposure to low-level fields, including environmental levels. Similarly, exposure to static electric fields at levels currently found in the living and working environment or acute exposure to static magnetic fields at flux densities below 2 T, were not found to have demonstrated adverse health consequences. However, reports of biological effects from low-level ELF-field exposure and chronic exposure to static magnetic fields were identified that need replication and further study for WHO to assess any possible health consequences. Ambient static electric fields have not been reported to cause any direct adverse health effects, and so no further research in this area was deemed necessary.
Bioelectromagnetics. 1999;20(3):133-60

Nonionizing electromagnetic fields and cancer: a review.
Salvatore JR, Weitberg AB, Mehta S.

National Registry for the Health Effects of Nonionizing Radiation, Brown University Medical School, USA.
Low-frequency electromagnetic radiation had previously been thought to cause human injury only by generation of excess heat or by shock from direct contact with electric current. Information accumulating over the past few decades, however, suggests that nonionizing electric and magnetic fields associated with this radiation may be an environmental etiology in human disease. Human beings are affected not only by natural background nonionizing electromagnetic fields produced by the Earth, but also by a host of manmade sources. Of the diseases believed related to these fields, cancer and participation of these fields in the carcinogenic process have received considerable attention. This paper is a review of the basic science that points to this possible association.
Oncology (Huntingt). 1996 Apr;10(4):563-70

Extremely low frequency electromagnetic fields (EMF) and brain cancer in adults and children: review and comment.
Gurney JG, van Wijngaarden E.
Division of Epidemiology/Clinical Research, Department of Pediatrics, School of Medicine, University of Minnesota, Minneapolis, MN 55455, USA.
Epidemiologic and experimental research on the potential carcinogenic effects of extremely low frequency electromagnetic fields (EMF) has now been conducted for over two decades. Cancer epidemiology studies in relation to EMF have focused primarily on brain cancer and leukemia, both from residential sources of exposure in children and adults and from occupational exposure in adult men. Because genotoxic effects of EMF have not been shown, most recent laboratory research has attempted to show biological effects that could be related to cancer promotion. In this report, we briefly review residential and occupational EMF studies on brain cancer. We also provide a general review of experimental studies as they relate both to the biological plausibility of an EMF-brain cancer relation and to the insufficiency of such research to help guide exposure assessment in epidemiologic studies. We conclude from our review that no recent research, either epidemiologic or experimental, has emerged to provide reasonable support for a causal role of EMF on brain cancer.
Neuro-oncol. 1999 Jul;1(3):212-20

Biological effects of power-frequency fields as they relate to carcinogenesis.
Moulder JE, Foster KR.
Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee 53226, USA.
There is a widespread public perception that exposure to electricity is linked to cancer. The public concern stems largely from epidemiological studies which appear to show a relationship between cancer incidence and exposure to power-frequency electromagnetic fields. This review will discuss the biophysics of power-frequency electromagnetic fields as it relates to biological effects, summarize the current state of the cancer epidemiology, and then concentrate on the laboratory studies that are relevant to addressing the possibility that power-frequency fields are carcinogenic. Review of the epidemiological evidence shows that the association between exposure to power-frequency fields and cancer is weak and inconsistent, and generally fails to show a dose-response relationship. The laboratory studies of power-frequency fields show little evidence of the type of effects on cells or animals that point towards power-frequency fields causing or contributing to cancer. Finally, from what is known about the biophysics of power-frequency fields, there is no reason to even suspect that they would cause or contribute to cancer. Application of "Hill's criteria" to epidemiological and laboratory studies shows that the evidence for a causal association between exposure to power-frequency fields and the incidence of cancer is weak.
Proc Soc Exp Biol Med. 1995 Sep;209(4):309-24

Power-frequency fields and cancer.

Moulder JE.
Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee 53226, USA.
There is a widespread public perception that exposure to "EMF" is linked to cancer. This concern stems largely from a few epidemiological studies that appear to show an association between cancer and residence near power lines. However, the epidemiological evidence for such a link falls far short of that needed to conclude that a causal relationship exists, and examination of the biophysics leads to the conclusion that biological effects are implausible at the field strengths encountered in environmental settings. In a case such as this, where the epidemiological evidence for a link between an agent and a disease is weak to nonexistent and the effect is biophysically and/or biochemically implausible, laboratory evidence becomes critical for risk evaluation. The mechanisms of carcinogenesis are sufficiently well established that laboratory studies can be used to assess whether an agent has carcinogenic potential. There are approximately 100 published reports that have looked for evidence that power-frequency fields have genotoxic or epigenetic activity. These studies have found no replicated evidence that power-frequency fields have the potential to either cause or contribute to cancer. Of the few studies that have shown some evidence for carcinogenic activity, most have used exposure conditions with little relevance to real world exposure, none have been replicated, and many have failed direct attempts at replication. In conjunction with the epidemiology and biophysics, this leads to the conclusion that a causal association between power-frequency fields and cancer is not only unproven, but rather unlikely.
Crit Rev Biomed Eng
. 1998;26(1-2):1-116

Do power frequency magnetic fields cause leukemia in children?
Levallois P.
Centre de santé publique, Centre hospitalier de l'Universite Laval, Quebec, Canada.
The possibility of a causal relationship between exposure to electromagnetic fields and childhood leukemia has been studied for more than 10 years. This review evaluates the epidemiologic findings relevant to a possible causal association between exposure to power frequency magnetic fields during childhood and leukemia. The nine published studies on this topic were analyzed, with a focus on the selection of subjects, assessment of exposure, and control of confounding. Consistency of a positive association and dose-response relationship are evident for assessment of past exposure: among the five recent studies, relative risk estimates vary from 1.5 to 2.7 for past exposure assessment, and a significant dose-response relation was found in three studies. These observations cannot be explained by misclassification of exposure or consistent selection bias, and a confounder effect could hardly explain such results. Even if there is no currently understood biological plausibility for such an association, its possible causal nature cannot be dismissed. The impact on public health of such a possible causal association is difficult to assess precisely but could be significant. Therefore, it might be prudent to consider interim preventive measures while we await results of further research.
Am J Prev Med. 1995 Jul-Aug;11(4):263-70

Biological effects of low frequency electromagnetic fields.
Doucet IL.
Medical Educational Trust, London.
Epidemiological studies since 1979 have raised some medical and much public concern that low frequency electromagnetic fields, such as those of power-lines and in domestic and industrial electrical wiring, may have harmful biological effects. These studies are generally inconsistent, inconclusive, and difficult to replicate. Identifying biological mechanisms by which such harmful effects may occur has proved difficult, although there are several new and promising approaches. In epidemiological and laboratory studies much greater co-ordination and standardization is needed if greater scientific knowledge of these phenomena, as opposed to mere diverse speculation, is to be achieved.
Med War. 1992 Jul-Sep;8(3):205-12

[Electromagnetic residential fields and childhood cancers: state of epidemiological research [Article in French]
Coste D, Moutet JP, Bernard JL.
Registre des Cancers de l'Enfant Provence-Alpes-Cote d'Azur et Corse, Faculte de Medecine, Marseille.
Thirteen epidemiological studies of the relations between electromagnetic fields and childhood cancers have been published. Eleven have shown some associations between the presumed intensity of exposure to residential magnetic fields and the childhood cancers incidence, either for all cancers or for the 3 most frequent types (leukaemias, brain tumours and lymphomas). These associations are not often significant because of the weak statistical power of these studies in relation with both the low incidence of cancers in childhood, and specially of each particular type, and the little number of subjects considered to be exposed at a high level exposure for residential magnetic fields. All these studies fall in with the same difficulties, particularly for identification and assessment of the exposure to magnetic fields and for the manner to take into account all the potential confounders. So even significant associations do not imply their causality, all the more as the carcinogenicity of extremely low frequency electromagnetic fields, although biologically conceivable, has never been experimentally proven. Today it is impossible to claim or invalidate the influence of residential magnetic fields in the genesis of childhood cancer. Setting up of new epidemiological studies based on large number of cases issued from population based registries and conducted with a best defined methodology seems to be highly desirable.
Rev Epidemiol Sante Publique. 1996 Jan;44(1):80-92.

[Biological effects of electromagnetic fields][Article in Japanese]
Shimizu H, Suzuki Y, Okonogi H.
Department of Public Health and Environmental Medicine, Jikei University School of Medicine, Tokyo, Japan.
Since several epidemiological studies have indicated an elevated risk for certain types of cancer in both living and working environments where exposure to an extremely low-frequency electromagnetic field (ELF) occurs, public concern about ELF has been increasing because it is impossible to imagine life today without electricity. We reviewed studies on biological effects of ELF with respect to their cytological and biochemical effects, including mutagenicity, clastogenicity and carcinogenicity. The studies can be summarized as follow: 1) There is evidence that outer surface of the cell membrane is the primary locus for ELF-induced cellular alterations. 2) ELF modulate the proliferation of normal as well as transformed cells in vivo and in vitro. The magnitude of the proliferative effects depends on ELF intensity, exposure duration and other cellular factors. 3) No studies clearly demonstrate deleterious effects of ELF exposure on mammalian reproduction and development, but several suggest such effects. 4) Reported evidence does not demonstrate that the ELF acts as a cancer initiator. However, it might act as a promoter or affect tumor progression. Further observations and epidemiological studies of ELF must be accompanied by laboratory experiments to evaluate biological and health effects.
Nippon Eiseigaku Zasshi. 1995 Dec;50(5):919-31

ELF: exposure levels, bioeffects, and epidemiology.
Anderson LE.
Pacific Northwest Laboratory, Richland, WA 99352.
Considerable information has been obtained within the last decade describing biological effects, both real and potential, of extremely low frequency (ELF) electric and magnetic fields. Additionally, advances have also been made in defining the interactions between such fields and living systems. Many of the current studies concerning ELF electromagnetic fields are focused on understanding the mechanisms of interaction and in elucidating the issues of human health impact. This paper provides an overview of recent progress in ELF research including work on dosimetry of the fields, laboratory animal studies, cellular research, and epidemiology.
Health Phys. 1991 Jul;61(1):41-6

Wire codes, magnetic fields, and childhood cancer.
Kheifets LI, Kavet R, Sussman SS.
Electric Power Research Institute, Palo Alto, California, USA. kheifets@eprinet.epri.com
Childhood cancer has been modestly associated with wire codes, an exposure surrogate for power frequency magnetic fields, but less consistently with measured fields. We analyzed data on the population distribution of wire codes and their relationship with several measured magnetic field metrics. In a given geographic area, there is a marked trend for decreased prevalence from low to high wire code categories, but there are differences between areas. For average measured fields, there is a positive relationship between the mean of the distributions and wire codes but a large overlap among the categories. Better discrimination is obtained for the extremes of the measurement values when comparing the highest and the lowest wire code categories. Instability of measurements, intermittent fields, or other exposure conditions do not appear to provide a viable explanation for the difference between wire codes and magnetic with respect to the strength and consistency of their respective association with childhood cancer.
Bioelectromagnetics. 1997;18(2):99-110