Cancer, Tumors, Infertility, Radiation Sickness

Various studies which conclude non-thermal biological effects from Microwave Radiation = 81
 
Cell phones and brain tumors: a review including the long-term epidemiologic data - 2009

http://www.ncbi.nlm.nih.gov/pubmed/19328536?dopt=Abstract

BACKGROUND: The debate regarding the health effects of low-intensity electromagnetic radiation from sources such as power lines, base stations, and cell phones has recently been reignited. In the present review, the authors attempt to address the following question: is there epidemiologic evidence for an association between long-term cell phone usage and the risk of developing a brain tumor? Included with this meta-analysis of the long-term epidemiologic data are a brief overview of cell phone technology and discussion of laboratory data, biological mechanisms, and brain tumor incidence.

METHODS: In order to be included in the present meta-analysis, studies were required to have met all of the following criteria: (i) publication in a peer-reviewed journal; (ii) inclusion of participants using cell phones for >/=10 years (ie, minimum 10-year "latency"); and (iii) incorporation of a "laterality" analysis of long-term users (ie, analysis of the side of the brain tumor relative to the side of the head preferred for cell phone usage). This is a meta-analysis incorporating all 11 long-term epidemiologic studies in this field.

RESULTS: The results indicate that using a cell phone for >/=10 years approximately doubles the risk of being diagnosed with a brain tumor on the same ("ipsilateral") side of the head as that preferred for cell phone use. The data achieve statistical significance for glioma and acoustic neuroma but not for meningioma. CONCLUSION: The authors conclude that there is adequate epidemiologic evidence to suggest a link between prolonged cell phone usage and the development of an ipsilateral brain tumor.

 

Non-Thermal Electromagnetic Radiation Damage to Lens Epithelium - 2008

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2694600&tool=pmcentrez&rendertype=abstract

High frequency microwave electromagnetic radiation from mobile phones and other modern devices has the potential to damage eye tissues, but its effect on the lens epithelium is unknown at present. The objective of this study was to investigate the non-thermal effects of high frequency microwave electromagnetic radiation (1.1GHz, 2.22 mW) on the eye lens epithelium in situ. Bovine lenses were incubated in organ culture at 35°C for 10-15 days. A novel computer-controlled microwave source was used to investigate the effects of microwave radiation on the lenses. 58 lenses were used in this study. The lenses were divided into four groups: (1) Control lenses incubated in organ culture for 10 to15 days. (2) Electromagnetic radiation exposure group treated with 1.1 GHz, 2.22 mW microwave radiation for 90 cycles of 50 minutes irradiation followed by 10 minutes pause and cultured up to 10 days. (3) Electromagnetic radiation exposure group treated as group 2 with 192 cycles of radiation and cultured for 15 days. (4) Lenses exposed to 39.5ºC for 2 hours 3 times with 24 hours interval after each treatment beginning on the second day of the culture and cultured for 11 days. During the culture period, lens optical quality was followed daily by a computer-operated scanning laser beam. At the end of the culture period, control and treated lenses were analyzed morphologically and by assessment of the lens epithelial ATPase activity. Exposure to 1.1 GHz, 2.22 mW microwaves caused a reversible decrease in lens optical quality accompanied by irreversible morphological and biochemical damage to the lens epithelial cell layer. The effect of the electromagnetic radiation on the lens epithelium was remarkably different from those of conductive heat. The results of this investigation showed that electromagnetic fields from microwave radiation have a negative impact on the eye lens. The lens damage by electromagnetic fields was distinctly different from that caused by conductive heat.

 

Public health implications of wireless technologies.Sage C, Carpenter DO. - 2009

Sage Associates, 1396 Danielson Road, Santa Barbara, CA 93108, USA.

http://www.ncbi.nlm.nih.gov/pubmed/19285839?ordinalpos=4&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

Global exposures to emerging wireless technologies from applications including mobile phones, cordless phones, DECT phones, WI-FI, WLAN, WiMAX, wireless internet, baby monitors, and others may present serious public health consequences. Evidence supporting a public health risk is documented in the BioInitiative Report. New, biologically based public exposure standards for chronic exposure to low-intensity exposures are warranted. Existing safety standards are obsolete because they are based solely on thermal effects from acute exposures. The rapidly expanding development of new wireless technologies and the long latency for the development of such serious diseases as brain cancers means that failure to take immediate action to reduce risks may result in an epidemic of potentially fatal diseases in the future. Regardless of whether or not the associations are causal, the strengths of the associations are sufficiently strong that in the opinion of the authors, taking action to reduce exposures is imperative, especially for the fetus and children. Such action is fully compatible with the precautionary principle, as enunciated by the Rio Declaration, the European Constitution Principle on Health (Section 3.1) and the European Union Treaties Article 174.

 

Physics and biology of mobile telephony.Hyland GJ. - 2000

Department of Physics, University of Warwick, Coventry, UK. G.J.Hyland@warwick.ac.uk

http://www.ncbi.nlm.nih.gov/pubmed/11117927?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

Although safety guidelines--to which mobile telephones and their base-stations conform--do protect against excessive microwave heating, there is evidence that the low intensity, pulsed radiation currently used can exert subtle non-thermal influences. If these influences entail adverse health consequences, current guidelines would be inadequate. This review will focus on this possibility. The radiation used is indeed of very low intensity, but an oscillatory similitude between this pulsed microwave radiation and certain electrochemical activities of the living human being should prompt concern. However, being so inherently dependent on aliveness, non-thermal effects cannot be expected to be as robust as thermal ones, as is indeed found; nor can everyone be expected to be affected in the same way by exposure to the same radiation. Notwithstanding uncertainty about whether the non-thermal influences reported do adversely affect health, there are consistencies between some of these effects and the neurological problems reported by some mobile-telephone users and people exposed longterm to base-station radiation. These should be pointers for future research.

 

Physical basis of adverse and therapeutic effects of low intensity microwave radiation.Hyland GJ. - 2008

International Institute of Biophysics, Landesstiftung Hombroich, Raketenstation, D-41472 Neuss, Germany. hyland1@onetel.com

http://www.ncbi.nlm.nih.gov/pubmed/18697627?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

A physical basis of adverse and therapeutic effects of low intensity microwave radiation is presented based on the concept of oscillatory similitude between the frequency of an external microwave field (together with any lower frequency modulations thereof) and those of certain endogenous dipolar coherent excitations allied to aliveness, which play the role of 'tuned circuits' via which a living organism is electromagnetically sensitised in a non-linear way to external fields too weak to be able to cause heating. From this perspective, an external electromagnetic field affects a living system not as a toxin but rather by perturbing its endogenous electromagnetic activity. The possibility of adverse perturbation is illustrated by reference to the microwave fields used in mobile telecommunications whose signals interfere in a non-thermal way with biofunctionality--in particular, undermining the efficacy of processes that would otherwise afford natural protection against the development of pathology. Therapeutic modalities of microwave exposure, on the other hand, are illustrated using the example of microwave resonance therapy--which can be considered as an electromagnetic version of acupuncture, and as an example of 'quantum medicine'--whose normalising effect on a wide range of pathologies is striking, and which affords a novel alternative to conventional pharmacological interventions.

 

Danger of cellular telephones and their relay stations - 2000

Santini R, Seigne M, Bonhomme-Faivre L.

http://www.ncbi.nlm.nih.gov/pubmed/10965528?ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

Cellular phones and their base stations emit pulsed microwaves in the environment. Cellular phone users are exposed in the near field and, under this condition, a large part of the electromagnetic energy is absorbed by the head, leading to an increased brain temperature. The general population is exposed under far field conditions to an electromagnetic intensity depending on the distance from the base station, passive re-emitters, the number of communications maintained by the base station and their position in relation to antennae (in front of the antenna or behind). Biological effects have been reported, such as radiofrequency sickness, electroencephalographic and blood pressure changes and also cancer risks in humans and animals exposed to microwave irradiation. Some European countries (Italy, France, Belgium, etc.) have taken measures to protect their populations.

 

Effects of electromagnetic fields on the immune systems of occupationally exposed humans and mice.Bonhomme-Faivre L, Marion S, Forestier F, Santini R, Auclair H. - 2003

Department Pharmacy, Laboratory of Pharmacology, Hôpital Paul Brousse, Villejuif, France. laurence.bonhomme-faivre@pbr.ap-hop-paris.fr

http://www.ncbi.nlm.nih.gov/pubmed/15702897?ordinalpos=7&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

The authors examined immunological disorders in 6 individuals who had been exposed occupationally to environmental electromagnetic fields. Comparable effects on mice exposed in a similar environment were also investigated. The human subjects had worked 8 hr/day for 5 yr in a laboratory located above electrical transformers and high-tension cables, and in which there were low-frequency electromagnetic fields of 0.2-6.6 microtesla (microT). The 6 control subjects (matched for socioeconomic parameters, sex, and age) had worked away from the immediate vicinity of transformers and high-tension cables. The authors found statistically significantly lower total lymphocyte, CD4, and CD3 counts, and significantly increased natural killer (NK) cells, in exposed subjects vs. controls. Six months after exposure had ceased, total lymphocyte counts had increased, as had CD4, CD3, and CD19 counts (+13%, +28%, +22%, and +17%, respectively), and NK cell counts were decreased by 26% (not significant) in the same human subjects. In the second part of this study, 12 Swiss male mice housed in cages were exposed in the same room in which the human subjects had been exposed (i.e., 5-microT, 50-Hz magnetic field) for 109 days; 12 additional mice were used as unexposed controls. The total lymphocyte, leukocyte, polymorphonuclear neutrophil, CD4, and NK counts of the exposed mice at 109 days were significantly lower than those of controls. In addition, plasma glucose levels (at 30 days) and amylase activity (at 109 days) were significantly lower, whereas plasma sodium and chloride levels were significantly elevated at 109 days. Results from this study suggest that chronic exposure to a 0.2-6.6-microT magnetic field can lead to decreased immunological parameters (total lymphocytes and CD4 counts) in both humans and mice. The increase in some values once exposure was terminated suggests a causal relationship with exposure to electromagnetic fields, as do the changes in mice, particularly the changes in total lymphocyte and CD4 counts.

 

Symptoms experienced by people in vicinity of base stations: II/ Incidences of age, duration of exposure, location of subjects in relation to the antennas and other electromagnetic factors - 2002

Santini R, Santini P, Danze JM, Le Ruz P, Seigne M.

Institut national des sciences appliquées, laboratoire de biochimie-pharmacologie, bâtiment Louis Pasteur, 20, avenue Albert Einstein, 69621 Villeurbanne, France. rsantini@insa-lyon.fr

http://www.ncbi.nlm.nih.gov/pubmed/12168254?ordinalpos=10&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

A survey study using questionnaire was conducted in 530 people (270 men, 260 women) living or not in vicinity of cellular phone base stations, on 18 Non Specific Health Symptoms. Comparisons of complaints frequencies (CHI-SQUARE test with Yates correction) in relation with distance from base station and sex, show significant (p < 0.05) increase as compared to people living > 300 m or not exposed to base station, till 300 m for tiredness, 200 m for headache, sleep disturbance, discomfort, etc. 100 m for irritability, depression, loss of memory, dizziness, libido decrease, etc. Women significantly more often than men (p < 0.05) complained of headache, nausea, loss of appetite, sleep disturbance, depression, discomfort and visual perturbations. This first study on symptoms experienced by people living in vicinity of base stations shows that, in view of radioprotection, minimal distance of people from cellular phone base stations should not be < 300 m.

 

Cellular telephones and their relay stations: a health risk? - 1999

Santini R.

Institut National des Sciences Appliquées, Laboratoire de Biochimie-Pharmacologie, Villeurbanne. rsantini@insa.insa.lyon.fr

http://www.ncbi.nlm.nih.gov/pubmed/10587726?ordinalpos=15&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

Portable cellular phones and their relay stations emit ultra-high frequency waves (microwaves) with amplitude modulation and extremely low frequency pulsation. The user is absorbed by the head and reaches the nervous structures leading to increased brain temperature. The general population is exposed to a distant field with an electromagnetic intensity which depends on the distance from the emitting antennas, the presence of "passive re-emitters", and the number of communications processed by the relay station. Among the main biological effects, "radio-frequency disease", electroencephalogram disturbances, and blood pressure disorders as well as risk of cancer have been observed in humans and animals.

 

Cell phones and brain tumors: a review including the long-term epidemiologic data.Khurana VG, Teo C, Kundi M, Hardell L, Carlberg M. - 2009

Australian National University, Australia. vgkhurana@gmail.com

http://www.ncbi.nlm.nih.gov/pubmed/19328536?ordinalpos=4&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

BACKGROUND: The debate regarding the health effects of low-intensity electromagnetic radiation from sources such as power lines, base stations, and cell phones has recently been reignited. In the present review, the authors attempt to address the following question: is there epidemiologic evidence for an association between long-term cell phone usage and the risk of developing a brain tumor? Included with this meta-analysis of the long-term epidemiologic data are a brief overview of cell phone technology and discussion of laboratory data, biological mechanisms, and brain tumor incidence. METHODS: In order to be included in the present meta-analysis, studies were required to have met all of the following criteria: (i) publication in a peer-reviewed journal; (ii) inclusion of participants using cell phones for > or = 10 years (ie, minimum 10-year "latency"); and (iii) incorporation of a "laterality" analysis of long-term users (ie, analysis of the side of the brain tumor relative to the side of the head preferred for cell phone usage). This is a meta-analysis incorporating all 11 long-term epidemiologic studies in this field. RESULTS: The results indicate that using a cell phone for > or = 10 years approximately doubles the risk of being diagnosed with a brain tumor on the same ("ipsilateral") side of the head as that preferred for cell phone use. The data achieve statistical significance for glioma and acoustic neuroma but not for meningioma. CONCLUSION: The authors conclude that there is adequate epidemiologic evidence to suggest a link between prolonged cell phone usage and the development of an ipsilateral brain tumor.

 

Mobile phones, cordless phones and the risk for brain tumours.Hardell L, Carlberg M. - 2009

Department of Oncology, Orebro University Hospital, SE-701 85 Orebro, Sweden. lennart.hardell@orebroll.se

http://www.ncbi.nlm.nih.gov/pubmed/19513546?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

The Hardell-group conducted during 1997-2003 two case control studies on brain tumours including assessment of use of mobile phones and cordless phones. The questionnaire was answered by 905 (90%) cases with malignant brain tumours, 1,254 (88%) cases with benign tumours and 2,162 (89%) population-based controls. Cases were reported from the Swedish Cancer Registries. Anatomical area in the brain for the tumour was assessed and related to side of the head used for both types of wireless phones. In the current analysis we defined ipsilateral use (same side as the tumour) as >or=50% of the use and contralateral use (opposite side) as <50% of the calling time. We report now further results for use of mobile and cordless phones. Regarding astrocytoma we found highest risk for ipsilateral mobile phone use in the >10 year latency group, OR=3.3, 95% CI=2.0-5.4 and for cordless phone use OR=5.0, 95% CI=2.3-11. In total, the risk was highest for cases with first use <20 years age, for mobile phone OR=5.2, 95% CI=2.2-12 and for cordless phone OR=4.4, 95% CI=1.9-10. For acoustic neuroma, the highest OR was found for ipsilateral use and >10 year latency, for mobile phone OR=3.0, 95% CI=1.4-6.2 and cordless phone OR=2.3, 95% CI=0.6-8.8. Overall highest OR for mobile phone use was found in subjects with first use at age <20 years, OR=5.0, 95% CI 1.5-16 whereas no association was found for cordless phone in that group, but based on only one exposed case. The annual age-adjusted incidence of astrocytoma for the age group >19 years increased significantly by +2.16%, 95% CI +0.25 to +4.10 during 2000-2007 in Sweden in spite of seemingly underreporting of cases to the Swedish Cancer Registry. A decreasing incidence was found for acoustic neuroma during the same period. However, the medical diagnosis and treatment of this tumour type has changed during recent years and underreporting from a single center would have a large impact for such a rare tumour.

 

Exposure to an 890-MHz mobile phone-like signal and serum levels of S100B and transthyretin in volunteers.Söderqvist F, Carlberg M, Hansson Mild K, Hardell L. - 2009

Department of Oncology, University Hospital, School of Health and Medical Sciences, Orebro University, Orebro SE-701 87, Sweden. fredrik.soderqvist@orebroll.se

http://www.ncbi.nlm.nih.gov/pubmed/19427372?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

Whether low-intensity non-thermal microwave radiation alters the integrity of the blood-brain barrier has been debated since the late 1970s, yet no experimental study has been carried out on humans. The aim of this study was to test, using peripheral markers, whether exposure to a mobile phone-like signal alters the integrity of the human blood-brain and blood-cerebrospinal fluid barriers. A provocation study was carried out that exposed 41 volunteers to a 30 min GSM 890 MHz signal with an average specific energy absorption rate distribution of 1.0 W/kg in the temporal area of the head as measured over any 1g of contiguous tissue. The outcome was assessed by changes in serum concentrations of two putative markers of brain barrier integrity, S100B and transthyretin. Repeated blood sampling before and after the provocation showed no statistically significant increase in the serum levels of S100B, while for transthyretin a statistically significant increase was seen in the final blood sample 60 min after the end of the provocation as compared to the prior sample taken immediately after provocation (p=0.02). The clinical significance of this finding, if any, is unknown. Further randomized studies with use of additional more brain specific markers are needed.

 

Mobile and cordless telephones, serum transthyretin and the blood-cerebrospinal fluid barrier: a cross-sectional study.Söderqvist F, Carlberg M, Hardell L. – 2009

Department of Oncology, University Hospital, Orebro, Sweden. fredrik.soderqvist@orebroll.se

http://www.ncbi.nlm.nih.gov/pubmed/19383125?ordinalpos=4&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

BACKGROUND: Whether low-intensity radiofrequency radiation damages the blood-brain barrier has long been debated, but little or no consideration has been given to the blood-cerebrospinal fluid barrier. In this cross-sectional study we tested whether long-term and/or short-term use of wireless telephones was associated with changes in the serum transthyretin level, indicating altered transthyretin concentration in the cerebrospinal fluid, possibly reflecting an effect of radiation. METHODS: One thousand subjects, 500 of each sex aged 18-65 years, were randomly recruited using the population registry. Data on wireless telephone use were assessed by a postal questionnaire and blood samples were analyzed for serum transthyretin concentrations determined by standard immunonephelometric techniques on a BN Prospec instrument. RESULTS: The response rate was 31.4%. Logistic regression of dichotomized TTR serum levels with a cut-point of 0.31 g/l on wireless telephone use yielded increased odds ratios that were statistically not significant. Linear regression of time since first use overall and on the day that blood was withdrawn gave different results for males and females: for men significantly higher serum concentrations of TTR were seen the longer an analogue telephone or a mobile and cordless desktop telephone combined had been used, and in contrast, significantly lower serum levels were seen the longer an UMTS telephone had been used. Adjustment for fractions of use of the different telephone types did not modify the effect for cumulative use or years since first use for mobile telephone and DECT, combined. For women, linear regression gave a significant association for short-term use of mobile and cordless telephones combined, indicating that the sooner blood was withdrawn after the most recent telephone call, the higher the expected transthyretin concentration. CONCLUSION: In this hypothesis-generating descriptive study time since first use of mobile telephones and DECT combined was significantly associated with higher TTR levels regardless of how much each telephone type had been used. Regarding short-term use, significantly higher TTR concentrations were seen in women the sooner blood was withdrawn after the most recent telephone call on that day.

 

Epidemiological evidence for an association between use of wireless phones and tumor diseases.Hardell L, Carlberg M, Hansson Mild K. - 2009

Department of Oncology, University Hospital, SE-701 85 Orebro, Sweden.

http://www.ncbi.nlm.nih.gov/pubmed/19268551?ordinalpos=6&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

During recent years there has been increasing public concern on potential cancer risks from microwave emissions from wireless phones. We evaluated the scientific evidence for long-term mobile phone use and the association with certain tumors in case-control studies, mostly from the Hardell group in Sweden and the Interphone study group. Regarding brain tumors the meta-analysis yielded for glioma odds ratio (OR)=1.0, 95% confidence interval (CI)=0.9-1.1. OR increased to 1.3, 95% CI=1.1-1.6 with 10 year latency period, with highest risk for ipsilateral exposure (same side as the tumor localisation), OR=1.9, 95% CI=1.4-2.4, lower for contralateral exposure (opposite side) OR=1.2, 95% CI=0.9-1.7. Regarding acoustic neuroma OR=1.0, 95% CI=0.8-1.1 was calculated increasing to OR=1.3, 95% CI=0.97-1.9 with 10 year latency period. For ipsilateral exposure OR=1.6, 95% CI=1.1-2.4, and for contralateral exposure OR=1.2, 95% CI=0.8-1.9 were found. Regarding meningioma no consistent pattern of an increased risk was found. Concerning age, highest risk was found in the age group <20 years at time of first use of wireless phones in the studies from the Hardell group. For salivary gland tumors, non-Hodgkin lymphoma and testicular cancer no consistent pattern of an association with use of wireless phones was found. One study on uveal melanoma yielded for probable/certain mobile phone use OR=4.2, 95% CI=1.2-14.5. One study on intratemporal facial nerve tumor was not possible to evaluate due to methodological shortcomings. In summary our review yielded a consistent pattern of an increased risk for glioma and acoustic neuroma after >10 year mobile phone use. We conclude that current standard for exposure to microwaves during mobile phone use is not safe for long-term exposure and needs to be revised.

 

Use of wireless telephones and serum S100B levels: a descriptive cross-sectional study among healthy Swedish adults aged 18-65 years.Söderqvist F, Carlberg M, Hardell L. - 2009

School of Health and Medical Sciences, Orebro University and Department of Oncology, University Hospital, SE-701 85 Orebro, Sweden. fredrik.soderqvist@orebroll.se

http://www.ncbi.nlm.nih.gov/pubmed/18986685?ordinalpos=7&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

BACKGROUND: Since the late 1970s, experimental animal studies have been carried out on the possible effects of low-intensive radiofrequency fields on the blood-brain barrier (BBB), but no epidemiological study has been published to date. OBJECTIVE: Using serum S100B as a putative marker of BBB dysfunction we performed a descriptive cross-sectional study to investigate whether protein levels were higher among frequent than non-frequent users of mobile and cordless desktop phones. METHOD: One thousand subjects, 500 of each sex aged 18-65 years, were randomly recruited using the population registry. Data on wireless phone use were assessed by a postal questionnaire and blood samples were analyzed for S100B. RESULTS: The response rate was 31.4%. The results from logistic and linear regression analyses were statistically insignificant, with one exception: the linear regression analysis of latency for UMTS use, which after stratifying on gender remained significant only for men (p = 0.01; n = 31). A low p-value (0.052) was obtained for use of cordless phone (n = 98) prior to giving the blood samples indicating a weak negative association. Total use of mobile and cordless phones over time yielded odds ratio (OR) 0.8 and 95% confidence interval (CI) 0.3-2.0 and use on the same day as giving blood yielded OR=1.1, CI=0.4-2.8. CONCLUSIONS: This study failed to show that long- or short-term use of wireless telephones was associated with elevated levels of serum S100B as a marker of BBB integrity. The finding regarding latency of UMTS use may be interesting but it is based on small numbers. Generally, S100B levels were low and to determine whether this association - if causal - is clinically relevant, larger studies with sufficient follow-up are needed.

 

Meta-analysis of long-term mobile phone use and the association with brain tumours.Hardell L, Carlberg M, Söderqvist F, Hansson Mild K. - 2008

Department of Oncology, University Hospital, SE-701 85 Orebro, Sweden. lennart.hardell@orebroll.se

http://www.ncbi.nlm.nih.gov/pubmed/18425337?ordinalpos=11&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

We evaluated long-term use of mobile phones and the risk for brain tumours in case-control studies published so far on this issue. We identified ten studies on glioma and meta-analysis yielded OR = 0.9, 95% CI = 0.8-1.1. Latency period of > or =10-years gave OR = 1.2, 95% CI = 0.8-1.9 based on six studies, for ipsilateral use (same side as tumour) OR = 2.0, 95% CI = 1.2-3.4 (four studies), but contralateral use did not increase the risk significantly, OR = 1.1, 95% CI = 0.6-2.0. Meta-analysis of nine studies on acoustic neuroma gave OR = 0.9, 95% CI = 0.7-1.1 increasing to OR = 1.3, 95% CI = 0.6-2.8 using > or =10-years latency period (four studies). Ipsilateral use gave OR = 2.4, 95% CI = 1.1-5.3 and contra-lateral OR = 1.2, 95% CI = 0.7-2.2 in the > or =10-years latency period group (three studies). Seven studies gave results for meningioma yielding overall OR = 0.8, 95% CI = 0.7-0.99. Using > or =10-years latency period OR = 1.3, 95% CI = 0.9-1.8 was calculated (four studies) increasing to OR = 1.7, 95% CI = 0.99-3.1 for ipsilateral use and OR = 1.0, 95% CI = 0.3-3.1 for contralateral use (two studies). We conclude that this meta-analysis gave a consistent pattern of an association between mobile phone use and ipsilateral glioma and acoustic neuroma using > or =10-years latency period.

 

Biological effects from electromagnetic field exposure and public exposure standards.Hardell L, Sage C. - 2008

Department of Oncology, University Hospital, SE-701 85 Orebro, Sweden. lennart.hardell@orebroll.se

http://www.ncbi.nlm.nih.gov/pubmed/18242044?ordinalpos=14&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

During recent years there has been increasing public concern on potential health risks from power-frequency fields (extremely low frequency electromagnetic fields; ELF) and from radiofrequency/microwave radiation emissions (RF) from wireless communications. Non-thermal (low-intensity) biological effects have not been considered for regulation of microwave exposure, although numerous scientific reports indicate such effects. The BioInitiative Report is based on an international research and public policy initiative to give an overview of what is known of biological effects that occur at low-intensity electromagnetic fields (EMFs) exposure. Health endpoints reported to be associated with ELF and/or RF include childhood leukaemia, brain tumours, genotoxic effects, neurological effects and neurodegenerative diseases, immune system deregulation, allergic and inflammatory responses, breast cancer, miscarriage and some cardiovascular effects. The BioInitiative Report concluded that a reasonable suspicion of risk exists based on clear evidence of bioeffects at environmentally relevant levels, which, with prolonged exposures may reasonably be presumed to result in health impacts. Regarding ELF a new lower public safety limit for habitable space adjacent to all new or upgraded power lines and for all other new constructions should be applied. A new lower limit should also be used for existing habitable space for children and/or women who are pregnant. A precautionary limit should be adopted for outdoor, cumulative RF exposure and for cumulative indoor RF fields with considerably lower limits than existing guidelines, see the BioInitiative Report. The current guidelines for the US and European microwave exposure from mobile phones, for the brain are 1.6 W/Kg and 2 W/Kg, respectively. Since use of mobile phones is associated with an increased risk for brain tumour after 10 years, a new biologically based guideline is warranted. Other health impacts associated with exposure to electromagnetic fields not summarized here may be found in the BioInitiative Report at www.bioinitiative.org.

 

Ownership and use of wireless telephones: a population-based study of Swedish children aged 7-14 years.Söderqvist F, Hardell L, Carlberg M, Hansson Mild K. - 2007

Department of Oncology, University Hospital, Institute of Clinical Medicine Orebro University, Orebro, Sweden. fredrik.soderqvist@orebroll.se

http://www.ncbi.nlm.nih.gov/pubmed/17561999?ordinalpos=20&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum
BACKGROUND: Recent years have seen a rapid increase in the use of mobile phones and other sources of microwave radiation, raising concerns about possible adverse health effects. As children have longer expected lifetime exposures to microwaves from these devices than adults, who started to use them later in life, they are a group of special interest. METHODS: We performed a population-based study to assess ownership and use of mobile phones and cordless phones among children aged 7-14 years. A questionnaire comprising 24 questions was sent to 2000 persons selected from the Swedish population registry using a stratified sampling scheme. RESULTS: The response rate was 71.2%. Overall, 79.1% of the respondents reported mobile phone access, and 26.7% of them talked for 2 minutes or more per day. Of those who reported mobile phone access, only 5.9% reported use of hands-free equipment. Use of cordless phones was reported by 83.8% of the respondents and 38.5% of them talked for 5 minutes or more per day. Girls generally reported more frequent use than boys. CONCLUSION: This study showed that most children had access to and used mobile and cordless phones early in life and that there was a rapid increase in use with age. It also showed very low use of hands-free equipment among children with mobile phone access, and finally that girls talked significantly more minutes per day using mobile and cordless phones than boys did.

 

Cell phone use and acoustic neuroma: the need for standardized questionnaires and access to industry data. - 2009

http://www.ncbi.nlm.nih.gov/pubmed/19328527?dopt=Abstract

BACKGROUND: The capacity of radiofrequency from cell phones to be absorbed into the brain has prompted concerns that regular cell phone use may increase the risk of acoustic neuroma (AN) and other brain tumors. This article critically evaluates current literature on cell phone use and AN risks and proposes additional studies to clarify any possible linkage. METHODS: Through a PubMed search, we identified and reviewed 10 case-control studies and 1 cohort study of AN risks associated with cell phone use and a meta-analysis of long-term mobile phone use and its association with AN and other brain tumors. RESULTS: Most studies did not find association between the development of AN and cell phone use, but some studies that followed cases for 10 years or more did show an association. Among 10 case-control studies, odds ratios for AN associated with regular cell phone use ranged from 0.5 (95% confidence interval [CI], 0.2-1.0) to 4.2 (95% CI, 1.8-10). Cell phone use was not associated with increased risk for AN in the Danish cohort study, which excluded business users from their study. The meta-analysis, which included 3 case-control studies, found that subjects who used cell phones for at least 10 years had a 2.4-fold greater risk of developing ipsilateral AN. In general, retrospective studies are limited in the ability to assess cell phone exposure because of recall bias and misclassification. CONCLUSIONS: The evaluation of AN risk factors is challenging due to its long latency. Some studies of longer term cell phone use have found an increased risk of ipsilateral AN. Adopting a prospective approach to acquire data on cell phone use, obtaining retrospective billing records that provide independent evaluations of exposures, and incorporating information on other key potential risk factors from questionnaires could markedly advance the capacity of studies to evaluate the impact of cell phones on AN.

 

Upregulation of specific mRNA levels in rat brain after cell phone exposure - 2008

http://www.ncbi.nlm.nih.gov/pubmed/18568932?dopt=Abstract

Adult Sprague-Dawley rats were exposed to regular cell phones for 6 h per day for 126 days (18 weeks). RT-PCR was used to investigate the changes in levels of mRNA synthesis of several injury-associated proteins. Calcium ATPase, Neural Cell Adhesion Molecule, Neural Growth Factor, and Vascular Endothelial Growth Factor were evaluated. The results showed statistically significant mRNA up-regulation of these proteins in the brains of rats exposed to cell phone radiation. These results indicate that relative chronic exposure to cell phone microwave radiation may result in cumulative injuries that could eventually lead to clinically significant neurological damage.

 

Radiofrequency electromagnetic fields; male infertility and sex ratio of offspring - 2008

http://www.ncbi.nlm.nih.gov/pubmed/18415687?dopt=Abstract

In all age groups there were significant linear trends with higher prevalence of involuntary childlessness with higher self-reported exposure to radiofrequency fields. However, the degree of exposure to radiofrequency radiation and the number of children were not associated. For self-reported exposure both to high-frequency aerials and communication equipment there were significant linear trends with lower ratio of boys to girls at birth when the father reported a higher degree of radiofrequency electromagnetic exposure.

Effects of radio frequency electromagnetic waves (RF-EMW) from cellular phones - 2008

http://www.ncbi.nlm.nih.gov/pubmed/18804757

Radiofrequency electromagnetic waves emitted from cell phones may lead to oxidative stress in human semen. We speculate that keeping the cell phone in a trouser pocket in talk mode may negatively affect spermatozoa and impair male fertility

Is fertility reduced among men exposed to radio frequency fields in the Norwegian Navy? – 2008

http://www.ncbi.nlm.nih.gov/pubmed/18240289?dopt=Abstract

This study shows a possible relationship between exposure to radiofrequency fields during work with radio frequency equipment and radar and reduced fertility. However, the results must be interpreted with caution..

Effect of cell phone usage on semen analysis in men attending infertility clinic - 2007

http://www.ncbi.nlm.nih.gov/pubmed/17482179?dopt=Abstract

Use of cell phones decrease the semen quality in men by decreasing the sperm count, motility, viability, and normal morphology. The decrease in sperm parameters was dependent on the duration of daily exposure to cell phones and independent of the initial semen quality.

Evaluation of the effect of using mobile phones on male fertility - 2007

http://www.ncbi.nlm.nih.gov/pubmed/17655195?dopt=Abstract

The following groups were selected from among 304 males covered by the study: Group A: 99 patients who did not use mobile phones, Group B: 157 males who have used GSM equipment sporadically for the period of 1-2 years, and Group C: 48 people who have been regularly using mobile phone for more than 2 years. In the analysis of the effect of GSM equipment on the semen it was noted that an increase in the percentage of sperm cells of abnormal morphology is associated with the duration of exposure to the waves emitted by the GSM phone. It was also confirmed that a decrease in the percentage of sperm cells in vital progressing motility in the semen is correlated with the frequency of using mobile phones.

Effects of cellular phone emissions on sperm motility in rats.

http://www.ncbi.nlm.nih.gov/pubmed/17628553?dopt=Abstract

Rats exposed to 6 hours of daily cellular phone emissions for 18 weeks exhibited a significantly higher incidence of sperm cell death than control group rats through chi-squared analysis. In addition, abnormal clumping of sperm cells was present in rats exposed to cellular phone emissions and was not present in control group rats.These results suggest that carrying cell phones near reproductive organs could negatively affect male fertility.

Effects of electromagnetic radiation from a cellular phone on human sperm motility: an in vitro study - 2006

http://www.ncbi.nlm.nih.gov/pubmed/16971222?dopt=Abstract

These data suggest that EMR emitted by cellular phone influences human sperm motility. In addition to these acute adverse effects of EMR on sperm motility, long-term EMR exposure may lead to behavioral or structural changes of the male germ cell. These effects may be observed later in life, and they are to be investigated more seriously.

Impact of radio frequency electromagnetic radiation on DNA integrity in the male germline - 2005

http://www.ncbi.nlm.nih.gov/pubmed/15910543

This study suggests that while RFEMR does not have a dramatic impact on male germ cell development, a significant genotoxic effect on epididymal spermatozoa is evident and deserves further investigation.

Is there a relationship between cell phone use and semen quality? - 2005

http://www.ncbi.nlm.nih.gov/pubmed/16087567?dopt=Abstract

The prolonged use of cell phones may have negative effects on the sperm motility characteristics.

 

1. Study of the health of people living in the vicinity of mobile phone base stations. Santini et al.

Pathol Biol (Paris) [Pathologie Biologie (Paris)] 2002; 50: 369 – 73

Found significant health effects on people living within 300 metres of mobile phone base stations.

Conclusions include the recommendation:

“… it is advisable that mobile phone base stations not be sited closer than 300meters to populations”

 

2. Netherlands Organization for Applied Scientific Research (TNO)

Study for the Netherlands Ministries of Economic Affairs, Housing, Spatial Planning and the Environment,and Health, Welfare and Sport

“Effects of Global Communications System Radio-Frequency Fields On Well Being and Cognitive Function of Human Subjects With and Without Subjective Complaints”

(September 2003)

Found significant effects on wellbeing, according to a number of internationally-recognised criteria (including headaches, muscle fatigue/pain, dizziness etc) from 3G mast emissions well below accepted ‘safety’ levels (less than 1/25,000th of ICNIRP guidelines). Those who had previously been noted as ‘electrosensitive’ under a scheme in that country were shown to have more pronounced ill-effects, though others were also shown to experience significant effects.

 

3. THE MICROWAVE SYNDROME - FURTHER ASPECTS OF A SPANISH STUDY

Oberfeld Gerd(1), Navarro A. Enrique(3), Portoles Manuel(2), Maestu Ceferino(4), GomezPerretta Claudio(2)

1) Public Health Department Salzburg, Austria

2) University Hospital La Fe. Valencia, Spain

3) Department of Applied Physics, University Valencia, Spain

4) Foundation European Bioelectromagnetism (FEB) Madrid, Spain

Presented at an International Conference in Kos (Greece), 2004

This study found significant ill-health effects in those living in the vicinity of two GSM mobile phone base stations. They observed that:

“The strongest five associations found are depressive tendency, fatigue, sleeping disorder, difficulty in concentration and cardiovascular problems.”

As their conclusion the research team wrote:

“Based on the data of this study the advice would be to strive for levels not higher than 0.02 V/m for the sum total, which is equal to a power density of 0.0001 µW/cni2 or 1 µW/m2, which is the indoor exposure value for GSM base stations proposed on empirical evidence by the Public Health Office of the Government of Salzburg in 2002.”

 

4. INCREASED INCIDENCE OF CANCER NEAR A CELL-PHONE TRANSMITTER STATION.

Ronni Wolf MD(1), Danny Wolf MD(2)

1. The Dermatology Unit, Kaplan Medical Center, Rechovot, and

the Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, ISRAEL.

2. The Pediatric Outpatient Clinic, Hasharon Region, Kupat Holim, ISRAEL.

Published in:

International Journal of Cancer Prevention Volume 1, No. 2, April 2004

This study, based on medical records of people living within 350 metres of a long-established phone mast, showed a fourfold increased incidence of cancer generally compared with the general population of Israel, and a tenfold increase specifically among women, compared with the surrounding locality further from the mast.

 

5. Naila Study, Germany (November 2004)

Report by researchers (five medical doctors)

Following the call by Wolfram König, President of the Bundesamt für Strahlenschutz (Federal Agency for radiation protection), to all doctors of medicine to collaborate actively in the assessment of the risk posed by cellular radiation, the aim of our study was to examine whether people living close to cellular transmitter antennas were exposed to a heightened risk of taking ill with malignant tumors.

The basis of the data used for the survey were PC fi1es of the case histories of patients between the years 1994 and 2004. While adhering to data protection, the personal data of almost 1.000 patients were evaluated for this study, which was completed without any external financial support. It is intended to continue the project in the form of a register.

The result of the study shows that the proportion of newly developing cancer cases was significantly higher among those patients who had lived during the past ten years at a distance of up to 400 metres from the cellular transmitter site, which bas been in operation since 1993, compared to those patients living further away, and that the patients fell ill on average 8 years earlier.

In the years 1999-2004, i.e. after five years’ operation of the transmitting installation, the relative risk of getting cancer had trebled for the residents of the area in the proximity of the installation compared to the inhabitants of Naila outside the area.

 

6. Austrian Study - Press Release 1st May 2005

The radiation of a cell phone base station at a distance of 80 metres causes significant changes of the electrical currents in the brains of testees (measured by electroencephalogram, EEG). All the testees said they felt unwell during the radiation, some of them seriously.

That is the result of an investigation by a team of Austrian scientists. They measured alpha 1 (8 to 10 Hz), alpha 2 (10 to 12 Hz) and beta waves (13 to 20 Hz). A small density of GSM 900 and GSM 1800 radiation already caused several significant changes in these three frequency ranges. This means the body is stressed - temporarily this may have some positive effect, in the long run however stress certainly reduces the quality of life, capacity for work and state of health.

The results of the research will be published in international scientific magazines and confirmed by replication. The research was financed by Land Salzburg in Austria. The testees were nine women and three men between 20 and 78, who considered themselves 'electrosensitive'. They were invited to sit in a chair, eyes covered and ears plugged. Of course they were not aware of the sequence of the tests.

The side of the room directed at the cell phone base station was shielded against radiation, except for a small part which could be (un)shielded easily. In the first phase, the radiation density near the head was 26 mikroWatt/m2, in the second phase 3327 mikroWatt/m2 and in the third phase 26 mikroWatt/m2 again. Several other environmental parameters were measured to be sure they could not influence the results, such as radiation by television and FM-radio, noise, CO2, temperature, relative humidity, low frequency magnetic fields and soherics (electrical discharges in the atmosphere, possibly causing radiation).

During the second phase the parameters of all the brainwaves, measured by EEG, changed significantly. Afterwards the testees were asked to describe their experiences. All of them felt unwell during the second phase. They reported symptoms like buzzing in the head, palpitations of the heart, unwellness, lightheadedness, anxiety, breathlessness, respiratory problems, nervousness, agitation, headache, tinnitus, heat sensation and depression.

According to the scientists, this is the first worldwide proof of significant changes of the electrical currents in the brain by a cell phone base station at a distance of 80 metres. It has been scientifically established before that the radiation of cell phone base stations leads to unwellness and health complaints.

The scientists involved were Dr. Med. Gerd Oberfeld (Land Salzburg, dept. of environmental medicin), Dr. Hannes Schimke (Salzburg University, EEG-measurements, psychofysiology, statistics) and Prof. Dr. Günther Bernatzky (Salzburg University, neurodynamics and neurosignalling). The research was supported by Dr. Med. Univ. Gernot Luthringshausen (permanent member of the ethical commission of Land Salzburg, neurology and psychiatry).

 

7. Israel study: fourfold cancer risk

Another study, this one from Israel's Tel Aviv University, examined 622 people living near a cell-phone transmitter station for 3-7 years who were patients in one clinic in Netanya and compared them against 1,222 control patients from a nearby clinic. Participants were very closely matched in environment, workplace and occupational characteristics. The people in the first group live within a half circle of 350m (1148 feet) radius from the transmitter, which came into service in July 1996.

The results were startling. Out of the 622 exposed patients, 8 cases of different kinds of cancer were diagnosed in a period of just one year (July 1997 to June 1998): 3 cases of breast cancer, one of ovarian cancer, lung cancer, Hodgkin's disease (cancer of the lymphatic system), osteoid osteoma (bone tumour) and kidney cancer. This compares with 2 per 1 222 in the matched controls of the nearby clinic. The relative risk of cancer was 4.15 for those living near the cell-phone transmitter compared with the entire population of Israel.

Women were more susceptible. As seven out of eight cancer cases were women, the relative cancer rates for females were 10.5 for those living near the transmitter station and 0.6 for the controls relative for the whole town of Netanya. One year after the close of the study, 8 new cases of cancer were diagnosed in the microwave exposed area and two in the control area.

 

Ahuja YR, Vijayashree B, Saran R, Jayashri EL, Manoranjani JK, Bhargava SC.

In vitro effects of low-level, low-frequency electromagnetic fields on DNA damage in

human leucocytes by comet assay. Indian J Biochem Biophys. 36(5):318-322, 1999.

(E)

The sources for the effects of electromagnetic fields (EMFs) have been traced to timevarying

as well as steady electric and magnetic fields, both at low and high to ultra high

frequencies. Of these, the effects of low-frequency (50/60 HZ) magnetic fields, directly

related to time-varying currents, are of particular interest as exposure to some fields may

be commonly experienced. In the present study, investigations have been carried out at

low-level (mT) and low-frequency (50 Hz) electromagnetic fields in healthy human

volunteers. Their peripheral blood samples were exposed to 5 doses of electromagnetic

fields (2,3,5,7 and 10mT at 50 Hz) and analysed by comet assay. The results were

compared to those obtained from unexposed samples from the same subjects. 50 cells per

treatment per individual were scored for comet-tail length which is an estimate of DNA

damage. Data from observations among males were pooled for each flux density for

analysis. At each flux density, with one exception, there was a significant increase in the

DNA damage from the control value. When compared with a similar study on females

carried out by us earlier, the DNA damage level was significantly higher in the females as

compared to the males for each flux density.

 

Cantoni O, Sestili P, Fiorani M, Dacha M. Effect of 50 Hz sinusoidal electric and/or

magnetic fields on the rate of repair of DNA single strand breaks in cultured

mammalian cells exposed to three different carcinogens: methylmethane

sulphonate, chromate and 254 nm U.V. radiation. Biochem Mol Biol Int. 38(3):527-

533, 1996. (NE)

Treatment of cultured mammalian cells with three different carcinogens, namely

methylmethane sulphonate (MMS), chromate and 254 U.V. radiation, produces DNA

single strand breaks (SSB) in cultured mammalian cells. The rate of removal of these

lesions is not affected by exposure to 50 Hz electric (0.2 - 20 kV/m), magnetic (0.0002-

0.2 mT), or combined electric and magnetic fields. These results indicate that, under the

experimental conditions utilized in this study, 50 Hz electric, magnetic and

electromagnetic fields (over a wide range of intensities) do not affect the machinery

involved in the repair of DNA SSBs generated by different carcinogens in three different

cultured mammalian cell lines, making it unlikely that field exposure enhances the ability

of these carcinogens to induce transformation via inhibition of DNA repair.

 

Chahal R, Craig DQ, Pinney RJ. Investigation of potential genotoxic effects of low

frequency electromagnetic fields on Escherichia coli. J Pharm Pharmacol. 45(1):30-33,

1993. (NE)

Exposure of growing cells of Escherichia coli strain AB1157 to a frequency of 1 Hz with

field strengths of 1 or 3 kV m-1 did not affect spontaneous or ultraviolet light (UV)-

induced mutation frequencies to rifampicin resistance. Neither did growth in the presence

of charge alter the sensitivities of strains AB1157, TK702 umuC or TK501 umuC uvrB to

UV. Similarly, although the resistance of strains TK702 umuC and TK501 umuC uvrB to

UV was increased by the presence of plasmid pKM101, which carries DNA repair genes,

pregrowth of plasmid-containing strains in electric fields did not increase UV resistance.

Finally, growth in a low frequency field in the presence of sub-inhibitory concentrations

of mitomycin C did not affect mitomycin C-induced mutation frequencies. It is concluded

that low frequency electromagnetic fields do not increase spontaneous mutation, induce

DNA repair or increase the mutagenic effects of UV or mitomycin C.

 

Chow K, Tung WL Magnetic field exposure enhances DNA repair through the

induction of DnaK/J synthesis. FEBS Lett. 478(1-2):133-136, 2000. (E)

In contrast to the common impression that exposure to a magnetic field of low frequency

causes mutations to organisms, we have demonstrated that a magnetic field can actually

enhance the efficiency of DNA repair. Using Escherichia coli strain XL-1 Blue as the

host and plasmid pUC8 that had been mutagenized by hydroxylamine as the vector for

assessment, we found that bacterial transformants that had been exposed to a magnetic

field of 50 Hz gave lower percentages of white colonies as compared to transformants

that had not been exposed to the magnetic field. This result was indicative that the

efficiency of DNA repair had been improved. The improvement was found to be

mediated by the induced overproduction of heat shock proteins DnaK/J (Hsp70/40).

 

Delimaris J, Tsilimigaki S, Messini-Nicolaki N, Ziros E, Piperakis SM Effects of

pulsed electric fields on DNA of human lymphocytes. Cell Biol Toxicol. 22(6):409-415,

2006. (E)

The effects of pulsed electric fields of low frequency (50 Hz) on DNA of human

lymphocytes were investigated. The influence of additional external factors, such as

hydrogen peroxide (H2O2) and gamma-irradiation, as well as the repair efficiency in these

lymphocytes, was also evaluated. The comet assay, a very sensitive and rapid method for

detecting DNA damage at the single cells level was the method used. A significant

amount of damage was observed after exposure to the electric fields, compared to the

controls. After 2 h incubation at 37 degrees C, a proportion of damage was repaired.

H2O2 and gamma-irradiation increased the damage to lymphocytes exposed to pulsed

electric fields according to the dose used, while the amount of the repair was proportional

to the damage.

 

Fairbairn DW, O'Neill KL The effect of electromagnetic field exposure on the

formation of DNA single strand breaks in human cells. Cell Mol Biol (Noisy-legrand).

40(4):561-567, 1994. (NE)

Electromagnetic fields (EMF) have been reported to be associated with human cancers in

a number of epidemiological studies. Agents that are associated with cancer affect DNA

in an adverse manner. This is a report of a DNA damage study in human cells exposed to

EMFs. Single strand breaks in DNA are proposed to be necessary events in both

mutagenesis and carcinogenesis. The single cell gel assay is a sensitive and accurate

technique that was used in this study for single strand break detection. The EMF

exposure system used here appeared to have no direct effect on DNA damage induction

in a series of experiments. Moreover, EMF did not have a significant effect in

potentiating DNA damage in cells treated with oxidative stresses.

 

Fiorani M, Cantoni O, Sestili P, Conti R, Nicolini P, Vetrano F, Dacha M. Electric

and/or magnetic field effects on DNA structure and function in cultured human

cells. Mutat Res. 282(1):25-29, 1992. (NE)

Exposure of cultured K562 cells to 50 Hz electric (0.2-20 kV/m), magnetic (0.002-2 G),

or combined electric and magnetic fields for up to 24 h did not result in the production of

detectable DNA lesions, as assayed by the filter elution technique. The rate of cell growth

was also unaffected as well as the intracellular ATP and NAD+ levels. These results

indicate that, under the experimental conditions utilized in this study, 50 Hz electric,

magnetic and electromagnetic fields are not geno- and cyto-toxic in cultured mammalian

cells.

 

Frazier ME, Reese JA, Morris JE, Jostes RF, Miller DL Exposure of mammalian

cells to 60-Hz magnetic or electric fields: analysis of DNA repair of induced, singlestrand

breaks. Bioelectromagnetics. 11(3):229-234, 1990. (NE)

DNA damage was induced in isolated human peripheral lymphocytes by exposure at 5

Gy to 60Co radiation. Cells were permitted to repair the DNA damage while exposed to

60-Hz fields or while sham-exposed. Exposed cells were subjected to magnetic (B) or

electric (E) fields, alone or in combination, throughout their allotted repair time. Repair

was stopped at specific times, and the cells were immediately lysed and then analyzed for

the presence of DNA single-strand breaks (SSB) by the alkaline-elution technique. Fifty

to 75 percent of the induced SSB were repaired 20 min after exposure, and most of the

remaining damage was repaired after 180 min. Cells were exposed to a 60-Hz ac B field

of 1 mT; an E field of 1 or 20 V/m; or combined E and B fields of 0.2 V/m and 0.05 mT,

6 V/m and 0.6 mT, or 20 V/m and 1 mT. None of the exposures was observed to affect

significantly the repair of DNA SSB.

 

Hong R, Zhang Y, Liu Y, Weng EQ. [Effects of extremely low frequency

electromagnetic fields on DNA of testicular cells and sperm chromatin structure in mice]

Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 23(6):414-417, 2005. (E)

[Article in Chinese]

OBJECTIVE: To study the effects of 50 Hz electromagnetic fields (EMFs) on DNA of

testicular cells and sperm chromatin structure in mice. METHODS: Mice were exposed

to 50 Hz, 0.2 mT or 6.4 mT electromagnetic fields for 4 weeks. DNA strand breakage in

testicular cells was detected by single-cell gel electrophoresis assay. Sperm chromatin

structure was analyzed by sperm chromatin structure assay with flow cytometry.

RESULTS: After 50 Hz, 0.2 mT or 6.4 mT EMFs exposure, the percentage of cells with

DNA migration in total testicular cells increased from the control level of 25.64% to

37.83% and 39.38% respectively. The relative length of comet tail and the percentage of

DNA in comet tail respectively increased from the control levels of 13.06% +/- 12.38%

and 1.52% +/- 3.25% to 17.86% +/- 14.60% and 2.32% +/- 4.26% after 0.2 mT exposure

and to 17.88% +/- 13.71% and 2.35% +/- 3.87% after 6.4 mT exposure (P < 0.05).

Exposure to EMFs had not induced significant changes in S.D.alphaT and XalphaT, but

COMPalphaT (cells outside the main population of alpha t), the percentage of sperms

with abnormal chromatin structure, increased in the two exposed groups.

CONCLUSION: 50 Hz EMFs may have the potential to induce DNA strand breakage in

testicular cells and sperm chromatin condensation in mice.

 

Ivancsits S, Pilger A, Diem E, Jahn O, Rudiger HW.Cell type-specific genotoxic

effects of intermittent extremely low-frequency electromagnetic fields. Mutat Res.

583(2):184-188, 2005. (E)

The issue of adverse health effects of extremely low-frequency electromagnetic fields

(ELF-EMFs) is highly controversial. Contradictory results regarding the genotoxic

potential of ELF-EMF have been reported in the literature. To test whether this

controversy might reflect differences between the cellular targets examined we exposed

cultured cells derived from different tissues to an intermittent ELF-EMF (50 Hz

sinusoidal, 1 mT) for 1-24h. The alkaline and neutral comet assays were used to assess

ELF-EMF-induced DNA strand breaks. We could identify three responder (human

fibroblasts, human melanocytes, rat granulosa cells) and three non-responder cell types

(human lymphocytes, human monocytes, human skeletal muscle cells), which points to

the significance of the cell system used when investigating genotoxic effects of ELFEMF.

 

Ivancsits S, Diem E, Jahn O, Rudiger HW. Age-related effects on induction of DNA

strand breaks by intermittent exposure to electromagnetic fields. Mech Ageing Dev.

124(7):847-850, 2003. (E)

Several studies indicating a decline of DNA repair efficiency with age raise the question,

if senescence per se leads to a higher susceptibility to DNA damage upon environmental

exposures. Cultured fibroblasts of six healthy donors of different age exposed to

intermittent ELF-EMF (50 Hz sinus, 1 mT) for 1-24 h exhibited different basal DNA

strand break levels correlating with age. The cells revealed a maximum response at 15-19

h of exposure. This response was clearly more pronounced in cells from older donors,

which could point to an age-related decrease of DNA repair efficiency of ELF-EMF

induced DNA strand breaks.

 

Ivancsits S, Diem E, Pilger A, Rudiger HW, Jahn O. Induction of DNA strand

breaks by intermittent exposure to extremely-low-frequency electromagnetic fields

in human diploid fibroblasts. Mutat Res. 519(1-2):1-13, 2002. (E)

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.

Ivancsits S, Diem E, Pilger A, Rudiger HW, Jahn O. Induction of DNA strand

breaks by intermittent exposure to extremely-low-frequency electromagnetic fields

in human diploid fibroblasts. Mutat Res. 519(1-2):1-13, 2002. (E)

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.

 

Jajte J, Zmyslony M, Palus J, Dziubaltowska E, Rajkowska E. Protective effect of

melatonin against in vitro iron ions and 7 mT 50 Hz magnetic field-induced DNA

damage in rat lymphocytes. Mutat Res. 483(1-2):57-64, 2001. (E)

We have previously shown that simultaneous exposure of rat lymphocytes to iron ions

and 50Hz magnetic field (MF) caused an increase in the number of cells with DNA

strand breaks. Although the mechanism of MF-induced DNA damage is not known, we

suppose that it involves free radicals. In the present study, to confirm our hypothesis, we

have examined the effect of melatonin, an established free radicals scavenger, on DNA

damage in rat peripheral blood lymphocytes exposed in vitro to iron ions and 50Hz MF.

The alkaline comet assay was chosen for the assessment of DNA damage. During preincubation,

part of the cell samples were supplemented with melatonin (0.5 or 1.0mM).

The experiments were performed on the cell samples incubated for 3h in Helmholtz coils

at 7mT 50Hz MF. During MF exposure, some samples were treated with ferrous chloride

(FeCl2, 10microg/ml), while the rest served as controls. A significant increase in the

number of cells with DNA damage was found only after simultaneous exposure of

lymphocytes to FeCl2 and 7mT 50Hz MF, compared to the control samples or those

incubated with FeCl2 alone. However, when the cells were treated with melatonin and

then exposed to iron ions and 50Hz MF, the number of damaged cells was significantly

reduced, and the effect depended on the concentration of melatonin. The reduction

reached about 50% at 0.5mM and about 100% at 1.0mM. Our results indicate that

melatonin provides protection against DNA damage in rat lymphocytes exposed in vitro

to iron ions and 50Hz MF (7mT). Therefore, it can be suggested that free radicals may be

involved in 50Hz magnetic field and iron ions-induced DNA damage in rat blood

lymphocytes. The future experimental studies, in vitro and in vivo, should provide an

answer to the question concerning the role of melatonin in the free radical processes in

the power frequency magnetic field.

 

Kindzelskii AL, Petty HR. Extremely low frequency pulsed DC electric fields

promote neutrophil extension, metabolic resonance and DNA damage when phasematched

with metabolic oscillators. Biochim Biophys Acta. 1495(1):90-111, 2000. (E)

Application of extremely low frequency pulsed DC electric fields that are frequency- and

phase-matched with endogenous metabolic oscillations leads to greatly exaggerated

neutrophil extension and metabolic resonance wherein oscillatory NAD(P)H amplitudes

are increased. In the presence of a resonant field, migrating cell length grows from 10 to

approximately 40 microm, as does the overall length of microfilament assemblies. In

contrast, cells stop locomotion and become spherical when exposed to phase-mismatched

fields. Although cellular effects were not found to be dependent on electrode type and

buffer, they were sensitive to temporal constraints (phase and pulse length) and cell

surface charge. We suggest an electromechanical coupling hypothesis wherein applied

electric fields and cytoskeletal polymerization forces act together to overcome the

surface/cortical tension of neutrophils, thus promoting net cytoskeletal assembly and

heightened metabolic amplitudes. Metabolic resonance enhances reactive oxygen

metabolic production by neutrophils. Furthermore, cellular DNA damage was observed

after prolonged metabolic resonance using both single cell gel electrophoresis ('comet'

assay) and 3'-OH DNA labeling using terminal deoxynucleotidyl transferase. These

results provide insights into transmembrane signal processing and cell interactions with

weak electric fields.

 

Lai H, Singh NP. Acute exposure to a 60 Hz magnetic field increases DNA strand

breaks in rat brain cells. Bioelectromagnetics. 18(2):156-165, 1997. (E)

Acute (2 h) exposure of rats to a 60 Hz magnetic field (flux densities 0.1, 0.25, and 0.5

mT) caused a dose-dependent increase in DNA strand breaks in brain cells of the animals

(assayed by a microgel electrophoresis method at 4 h postexposure). An increase in

single-strand DNA breaks was observed after exposure to magnetic fields of 0.1, 0.25,

and 0.5 mT, whereas an increase in double-strand DNA breaks was observed at 0.25 and

0.5 mT. Because DNA strand breaks may affect cellular functions, lead to carcinogenesis

and cell death, and be related to onset of neurodegenerative diseases, our data may have

important implications for the possible health effects of exposure to 60 Hz magnetic

fields.

 

Lai H, Singh NP. Magnetic-field-induced DNA strand breaks in brain cells of the

rat. Environ Health Perspect. 112(6):687-694, 2004. (E)

In previous research, we found that rats acutely (2 hr) exposed to a 60-Hz sinusoidal

magnetic field at intensities of 0.1-0.5 millitesla (mT) showed increases in DNA single and double-strand breaks in their brain cells. Further research showed that these effects

could be blocked by pretreating the rats with the free radical scavengers melatonin and Ntert-butyl-alpha-phenylnitrone, suggesting the involvement of free radicals. In the present study, effects of magnetic field exposure on brain cell DNA in the rat were further investigated. Exposure to a 60-Hz magnetic field at 0.01 mT for 24 hr caused a

significant increase in DNA single- and double-strand breaks. Prolonging the exposure to

48 hr caused a larger increase. This indicates that the effect is cumulative. In addition,

treatment with Trolox (a vitamin E analog) or 7-nitroindazole (a nitric oxide synthase

inhibitor) blocked magnetic-field-induced DNA strand breaks. These data further support

a role of free radicals on the effects of magnetic fields. Treatment with the iron chelator

deferiprone also blocked the effects of magnetic fields on brain cell DNA, suggesting the

involvement of iron. Acute magnetic field exposure increased apoptosis and necrosis of

brain cells in the rat. We hypothesize that exposure to a 60-Hz magnetic field initiates an

iron-mediated process (e.g., the Fenton reaction) that increases free radical formation in

brain cells, leading to DNA strand breaks and cell death. This hypothesis could have an

important implication for the possible health effects associated with exposure to

extremely low-frequency magnetic fields in the public and occupational environments.

 

Lai H, Singh NP. Melatonin and N-tert-butyl-alpha-phenylnitrone block 60-Hz

magnetic field-induced DNA single and double strand breaks in rat brain cells. J

Pineal Res. 22(3):152-162, 1997. (E)

In previous research, we have found an increase in DNA single- and double-strand breaks

in brain cells of rats after acute exposure (two hours) to a sinusoidal 60-Hz magnetic

field. The present experiment was carried out to investigate whether treatment with

melatonin and the spin-trap compound N-tert-butyl-alpha-phenylnitrone (PBN) could

block the effect of magnetic fields on brain cell DNA. Rats were injected with melatonin

(1 mg/kg, sc) or PBN (100 mg/kg, ip) immediately before and after two hours of

exposure to a 60-Hz magnetic field at an intensity of 0.5 mT. We found that both drug

treatments blocked the magnetic field-induced DNA single- and double-strand breaks in

brain cells, as assayed by a microgel electrophoresis method. Since melatonin and PBN

are efficient free radical scavengers, these data suggest that free radicals may play a role

in magnetic field-induced DNA damage.

 

Li SH, Chow KC. Magnetic field exposure induces DNA degradation. Biochem

Biophys Res Commun. 280(5):1385-1388, 2001. (E)

In our earlier experiments, we discovered that magnetic field exposure could bring both

stabilizing and destabilizing effects to the DNA of Escherichia coli, depending on our

parameters of assessment, and both of these effects were associated with the induced

synthesis of the heat shock proteins Hsp70/Hsp40 (DnaK/DnaJ). These contradicting

results prompted us to explore in this study the effect of magnetic field exposure on the

DNA stability in vivo when the heat shock response of the cell was suppressed. By using

plasmid pUC18 in E. coli as the indicator, we found that without the protection of the

heat shock response, magnetic field exposure indeed induced DNA degradation and this

deleterious effect could be diminished by the presence of an antioxidant, Trolox C. In our

in vitro test, we also showed that the magnetic field could potentiate the activity of

oxidant radicals.

 

Lopucki M, Schmerold I, Dadak A, Wiktor H, Niedermuller H, Kankofer M. Low

dose magnetic fields do not cause oxidative DNA damage in human placental

cotyledons in vitro. Virchows Arch. 446(6):634-639, 2005. (NE)

The biological impact of low dose magnetic fields generated by electric appliances

present in the human environment is still uncertain. In this study, human placentas served

as a model tissue for the evaluation of the potential effect of oscillating low intensity

magnetic fields on the concentration of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in

cellular DNA. Cotyledons were dissected from placentas obtained immediately after

physiological labours and exposed to magnetic fields (groups MF A, 2 mT, 50 Hz and

MF B, 5 mT, 50 Hz) or sham exposed (group C) during an in vitro perfusion of 3 h.

Cellular DNA was isolated, hydrolyzed and analyzed by HPLC. Native nucleosides were

monitored at 254 nm and 8-OH-dG by electrochemical detection. Results were expressed

as mumol 8-OH-dG/mol deoxyguanosine (dG). The concentrations of 8-OH-dG in group

C, MF A and MF B were 28.45+/-15.27 micromol/mol dG, 62.80+/-31.91 mumol/mol

dG, and 27.49+/-14.23 micromol/mol dG, respectively, demonstrating no significant

difference between the groups. The results suggest that placental tissues possess a

capacity to protect DNA against oxidative alterations by magnetic field of intensities

previously shown to produce radical mediated DNA damage in rat brain cells in vivo and

imbalances in electrolyte release of cotyledons under in vitro conditions.

 

Lourencini da Silva R, Albano F, Lopes dos Santos LR, Tavares AD Jr,

Felzenszwalb I. The effect of electromagnetic field exposure on the formation of

DNA lesions. Redox Rep. 5(5):299-301, 2000. (E)

In an attempt to determine whether electromagnetic field (EMF) exposure might lead to

DNA damage, we exposed SnCl2-treated pBR322 plasmids to EMF and analysed the

resulting conformational changes using agarose gel electrophoresis. An EMF-dependent

potentiation of DNA scission (i.e. the appearance of relaxed plasmids) was observed. In

confirmation of this, plasmids pre-exposed to EMF also were less capable of

transforming Escherichia coli. The results indicate that EMF, in the presence of a

transition metal, is capable of causing DNA damage. These observations support the idea

that EMF, probably through secondary generation of reactive oxygen species, can be

clastogenic and provide a possible explanation for the observed correlation between EMF

exposure and the frequency of certain types of cancers in humans.

 

Luceri C, De Filippo C, Giovannelli L, Blangiardo M, Cavalieri D, Aglietti F,

Pampaloni M, Andreuccetti D, Pieri L, Bambi F, Biggeri A, Dolara P. Extremely

low-frequency electromagnetic fields do not affect DNA damage and gene expression

profiles of yeast and human lymphocytes. Radiat Res. 164(3):277-285, 2005. (NE)

We studied the effects of extremely low-frequency (50 Hz) electromagnetic fields

(EMFs) on peripheral human blood lymphocytes and DBY747 Saccharomyces

cerevisiae. Graded exposure to 50 Hz magnetic flux density was obtained with a

Helmholtz coil system set at 1, 10 or 100 microT for 18 h. The effects of EMFs on DNA

damage were studied with the single-cell gel electrophoresis assay (comet assay) in

lymphocytes. Gene expression profiles of EMF-exposed human and yeast cells were

evaluated with DNA microarrays containing 13,971 and 6,212 oligonucleotides,

respectively. After exposure to the EMF, we did not observe an increase in the amount of

strand breaks or oxidated DNA bases relative to controls or a variation in gene expression

profiles. The results suggest that extremely low-frequency EMFs do not induce DNA

damage or affect gene expression in these two different eukaryotic cell systems.

 

McNamee JP, Bellier PV, McLean JR, Marro L, Gajda GB, Thansandote A. DNA

damage and apoptosis in the immature mouse cerebellum after acute exposure to a

1 mT, 60 Hz magnetic field. Mutat Res. 513(1-2):121-133, 2002. (NE)

Several recent studies have reported that whole-body exposure of rodents to power

frequency magnetic fields (MFs) can result in DNA single- and double-strand breaks in

the brains of these animals. The current study was undertaken to investigate whether an

acute 2h exposure of a 1 mT, 60 Hz MF could elicit DNA damage, and subsequently

apoptosis, in the brains of immature (10-day-old) mice. DNA damage was quantitated at

0, 2, 4, and 24h after exposure using the alkaline comet assay. Apoptosis was quantitated

in the external granule cell layer (EGCL) of the immature mouse cerebellum at 0 and 24h

after exposure to MF by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Four

parameters (tail ratio, tail moment, comet length and tail length) were used to assess

DNA damage for each comet. While increased DNA damage was detected by tail ratio at

2h after MF exposure, no supporting evidence of increased DNA damage was detected by

the other parameters. In addition, no similar differences were observed using these

parameters at any of the other post-exposure times. No increase in apoptosis was

observed in the EGCL of MF-exposed mice, when compared to sham mice. Taken

together, these results do not support the hypothesis that acute MF exposure causes DNA

damage in the cerebellums of immature mice.

 

McNamee JP, Bellier PV, Chauhan V, Gajda GB, Lemay E, Thansandote A.

Evaluating DNA damage in rodent brain after acute 60 Hz magnetic-field exposure.

Radiat Res. 164(6):791-797, 2005. (NE)

In recent years, numerous studies have reported a weak association between 60 Hz

magnetic-field exposure and the incidence of certain cancers. To date, no mechanism to

explain these findings has been identified. The objective of the current study was to

investigate whether acute magnetic-field exposure could elicit DNA damage within brain

cells from both whole brain and cerebellar homogenates from adult rats, adult mice and

immature mice. Rodents were exposed to a 60 Hz magnetic field (0, 0.1, 1 or 2 mT) for 2

h. Then, at 0, 2 and 4 h after exposure, animals were killed humanely, their brains were

rapidly removed and homogenized, and cells were cast into agarose gels for processing

by the alkaline comet assay. Four parameters (tail ratio, tail moment, comet length and

tail length) were used to assess DNA damage for each comet. For each species, a

significant increase in DNA damage was detected by each of the four parameters in the

positive control (2 Gy X rays) relative to the concurrent nonirradiated negative and sham

controls. However, none of the four parameters detected a significant increase in DNA

damage in brain cell homogenates from any magnetic-field exposure (0- 2 mT) at any

time after exposure. The dose-response and time-course data from the multiple animal

groups tested in this study provide no evidence of magnetic-field-induced DNA damage.

 

Miyakoshi J, Yoshida M, Shibuya K, Hiraoka M. Exposure to strong magnetic

fields at power frequency potentiates X-ray-induced DNA strand breaks. J Radiat

Res (Tokyo). 41(3):293-302, 2000. (E)

We examined the effect of an extremely low-frequency magnetic field (ELFMF) at 5, 50

and 400 mT on DNA strand breaks in human glioma MO54 cells. A DNA damage

analysis was performed using the method of alkaline comet assay. The cells were

exposed to X-rays alone (5 Gy), ELFMF alone, or X-rays followed by ELFMF at 4

degrees C or on ice. No significant difference in the tail moment was observed between

control and ELFMF exposures up to 400 mT. X-ray irradiation increased DNA strand

breaks. When cells were exposed to X-rays followed by ELFMF at 50 and 400 mT, the

tail moment increased significantly compared with that for X-rays alone. When the

exposure of cells was performed at 37 degrees C, no significant change was observed

between X-rays alone and X-rays plus 400 mT. We previously observed that exposure to

400 mT ELFMF for 2 h increased X-ray-induced mutations (Miyakoshi et al, Mutat.

Res., 349: 109-114, 1996). Additionally, an increase in the mutation by exposure to the

ELFMF was observed in cells during DNA-synthesizing phase (Miyakoshi et al., Int. J.

Radiat. Biol., 71: 75-79, 1997). From these results, it appears that exposure to the high

density ELFMF at more than 50 mT may potentiate X-ray-induced DNA strand breaks.

 

Moretti M, Villarini M, Simonucci S, Fatigoni C, Scassellati-Sforzolini G, Monarca

S, Pasquini R, Angelucci M, Strappini M Effects of co-exposure to extremely low

frequency (ELF) magnetic fields and benzene or benzene metabolites determined in

vitro by the alkaline comet assay. Toxicol Lett. 157(2):119-128, 2005. (E)

In the present study, we investigated in vitro the possible genotoxic and/or co-genotoxic

activity of 50 Hz (power frequency) magnetic fields (MF) by using the alkaline singlecell

microgel-electrophoresis (comet) assay. Sets of experiments were performed to

evaluate the possible interaction between 50 Hz MF and the known leukemogen benzene.

Three benzene hydroxylated metabolites were also evaluated: 1,2-benzenediol (1,2-BD,

catechol), 1,4-benzenediol (1,4-BD, hydroquinone), and 1,2,4-benzenetriol (1,2,4-BT).

MF (1 mT) were generated by a system consisting of a pair of parallel coils in a

Helmholtz configuration. To evaluate the genotoxic potential of 50 Hz MF, Jurkat cell

cultures were exposed to 1 mT MF or sham-exposed for 1h. To evaluate the co-genotoxic

activity of MF, the xenobiotics (benzene, catechol, hydroquinone, and 1,2,4-benzenetriol)

were added to Jurkat cells subcultures at the beginning of the exposure time. In cell

cultures co-exposed to 1 mT (50 Hz) MF, benzene and catechol did not show any

genotoxic activity. However, co-exposure of cell cultures to 1 mT MF and hydroquinone

led to the appearance of a clear genotoxic effect. Moreover, co-exposure of cell cultures

to 1 mT MF and 1,2,4-benzenetriol led to a marked increase in the genotoxicity of the

ultimate metabolite of benzene. The possibility that 50 Hz (power frequency) MF might

interfere with the genotoxic activity of xenobiotics has important implications, since

human populations are likely to be exposed to a variety of genotoxic agents

concomitantly with exposure to this type of physical agent.

 

Nikolova T, Czyz J, Rolletschek A, Blyszczuk P, Fuchs J, Jovtchev G, Schuderer J,

Kuster N, Wobus AM. Electromagnetic fields affect transcript levels of apoptosisrelated

genes in embryonic stem cell-derived neural progenitor cells. ASEB J.

19(12):1686-1688, 2005. (E)

Mouse embryonic stem (ES) cells were used as an experimental model to study the

effects of electromagnetic fields (EMF). ES-derived nestin-positive neural progenitor

cells were exposed to extremely low frequency EMF simulating power line magnetic

fields at 50 Hz (ELF-EMF) and to radiofrequency EMF simulating the Global System for

Mobile Communication (GSM) signals at 1.71 GHz (RF-EMF). Following EMF

exposure, cells were analyzed for transcript levels of cell cycle regulatory, apoptosisrelated, and neural-specific genes and proteins; changes in proliferation; apoptosis; and cytogenetic effects. Quantitative RT-PCR analysis revealed that ELF-EMF exposure to ES-derived neural cells significantly affected transcript levels of the apoptosis-related bcl-2, bax, and cell cycle regulatory "growth arrest DNA damage inducible" GADD45 genes, whereas mRNA levels of neural-specific genes were not affected. RF-EMF exposure of neural progenitor cells resulted in down-regulation of neural-specific Nurr1 and in up-regulation of bax and GADD45 mRNA levels. Short-term RF-EMF exposure for 6 h, but not for 48 h, resulted in a low and transient increase of DNA double-strand breaks. No effects of ELF- and RF-EMF on mitochondrial function, nuclear apoptosis, cell proliferation, and chromosomal alterations were observed. We may conclude that EMF exposure of ES-derived neural progenitor cells transiently affects the transcript level of genes related to apoptosis and cell cycle control. However, these responses are not associated with detectable changes of cell physiology, suggesting compensatory mechanisms at the translational and posttranslational level.

 

Reese JA, Jostes RF, Frazier ME. Exposure of mammalian cells to 60-Hz magnetic

or electric fields: analysis for DNA single-strand breaks. Bioelectromagnetics.

9(3):237-247, 1998. (NE)

Chinese hamster ovary (CHO) cells were exposed for 1 h to 60-Hz magnetic fields (0.1 or

2 mT), electric fields (1 or 38 V/m), or to combined magnetic and electric fields (2 mT

and 38 V/m, respectively). Following exposure, the cells were lysed, and the DNA was

analyzed for the presence of single-strand breaks (SSB), using the alkaline elution

technique. No significant differences in numbers of DNA SSB were detected between

exposed and sham-exposed cells. A positive control exposed to X-irradiation sustained

SSB with a dose-related frequency. Cells exposed to nitrogen mustard (a known crosslinking agent) and X-irradiation demonstrated that the assay could detect cross-linked DNA under our conditions of electric and magnetic field exposures.

 

Robison JG, Pendleton AR, Monson KO, Murray BK, O'Neill KL. Decreased DNA

repair rates and protection from heat induced apoptosis mediated by

electromagnetic field exposure. Bioelectromagnetics. 23(2):106-112, 2002. (E)

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.

 

Scarfi MR, Sannino A, Perrotta A, Sarti M, Mesirca P, Bersani F. Evaluation of

genotoxic effects in human fibroblasts after intermittent exposure to 50 Hz

electromagnetic fields: a confirmatory study. Radiat Res. 164(3):270-276, 2005. (NE)

The aim of this investigation was to confirm the main results reported in recent studies on

the induction of genotoxic effects in human fibroblasts exposed to 50 Hz intermittent (5

min field on/10 min field off) sinusoidal electromagnetic fields. For this purpose, the

induction of DNA single-strand breaks was evaluated by applying the alkaline single-cell

gel electrophoresis (SCGE)/comet assay. To extend the study and validate the results, in

the same experimental conditions, the potential genotoxicity was also tested by exposing

the cells to a 50 Hz powerline signal (50 Hz frequency plus its harmonics). The

cytokinesis-block micronucleus assay was applied after 24 h intermittent exposure to

both sinusoidal and powerline signals to obtain information on cell cycle kinetics. The

experiments were carried out on human diploid fibroblasts (ES-1). For each experimental

run, exposed and sham-exposed samples were set up; positive controls were also

provided by treating cells with hydrogen peroxide or mitomycin C for the comet or

micronucleus assay, respectively. No statistically significant difference was detected in

exposed compared to sham-exposed samples in any of the experimental conditions tested

(P > 0.05). In contrast, the positive controls showed a statistically significant increase in

DNA damage in all cases, as expected. Accordingly, our findings do not confirm the

results reported previously for either comet induction or an increase in micronucleus

frequency.

 

Schmitz C, Keller E, Freuding T, Silny J, Korr H. 50-Hz magnetic field exposure

influences DNA repair and mitochondrial DNA synthesis of distinct cell types in

brain and kidney of adult mice. Acta Neuropathol (Berl). 107(3):257-264, 2004. (E)

Despite several recent investigations, the impact of whole-body magnetic field exposure

on cell-type-specific alterations due to DNA damage and DNA repair remains unclear. In

this pilot study adult mice were exposed to 50-Hz magnetic field (mean value 1.5 mT) for

8 weeks or left unexposed. Five minutes after ending exposure, the mice received

[(3)H]thymidine and were killed 2 h later. Autoradiographs were prepared from paraffin

sections of brains and kidneys for measuring unscheduled DNA synthesis and

mitochondrial DNA synthesis, or in situ nick translation with DNA polymerase-I and

[(3)H]dTTP. A significant (P<0.05) increase in both unscheduled DNA synthesis and in

situ nick translation was only found for epithelial cells of the choroid plexus. Thus, these

two independent methods indicate that nuclear DNA damage is produced by long-lasting

and strong magnetic field exposure. The fact that only plexus epithelial cells were

affected might point to possible effects of magnetic fields on iron transport across the

blood-cerebrospinal fluid barrier, but the mechanisms are currently not understood.

Mitochondrial DNA synthesis was exclusively increased in renal epithelial cells of distal

convoluted tubules and collecting ducts, i.e., cells with a very high content of

mitochondria, possibly indicating increased metabolic activity of these cells.

 

Singh N, Lai H. 60 Hz magnetic field exposure induces DNA crosslinks in rat brain

cells. Mutat Res. 400(1-2):313-320, 1998. (E)

In previous research, we found an increase in DNA strand breaks in brain cells of rats

acutely exposed to a 60 Hz magnetic field (for 2 h at an intensity of 0.5 mT). DNA strand

breaks were measured with a microgel electrophoresis assay using the length of DNA

migration as an index. In the present experiment, we found that most of the magnetic

field-induced increase in DNA migration was observed only after proteinase-K treatment,

suggesting that the field caused DNA-protein crosslinks. In addition, when brain cells

from control rats were exposed to X-rays, an increase in DNA migration was observed,

the extent of which was independent of proteinase-K treatment. However, the X-rayinduced increase in DNA migration was retarded in cells from animals exposed to

magnetic fields even after proteinase-K treatment, suggesting that DNA-DNA crosslinks

were also induced by the magnetic field. The effects of magnetic fields were also

compared with those of a known DNA crosslink-inducing agent mitomycin C. The

pattern of effects is similar between the two agents. These data suggest that both DNA protein and DNA-DNA crosslinks are formed in brain cells of rats after acute exposure to

a 60 Hz magnetic field.

 

Stronati L, Testa A, Villani P, Marino C, Lovisolo GA, Conti D, Russo F, Fresegna

AM, Cordelli E Absence of genotoxicity in human blood cells exposed to 50 Hz

magnetic fields as assessed by comet assay, chromosome aberration, micronucleus,

and sister chromatid exchange analyses. Bioelectromagnetics. 25(1):41-48, 2004. (NE)

In the past, epidemiological studies indicated a possible correlation between the exposure

to ELF fields and cancer. Public concern over possible hazards associated with exposure

to extremely low frequency magnetic fields (ELFMFs) stimulated an increased scientific

research effort. More recent research and laboratory studies, however, have not been able

to definitively confirm the correlation suggested by epidemiological studies. The aim of

this study was to evaluate the effects of 50 Hz magnetic fields in human blood cells

exposed in vitro, using several methodological approaches for the detection of

genotoxicity. Whole blood samples obtained from five donors were exposed for 2 h to 50

Hz, 1 mT uniform magnetic field generated by a Helmholtz coil system. Comet assay,

sister chromatid exchanges (SCE), chromosome aberrations (CA), and micronucleus

(MN) tests were used to assess DNA damage, one hallmark of malignant cell

transformation. The effects of a combined exposure with X-rays were also evaluated.

Results obtained do not show any significant difference between ELFMFs exposed and

unexposed samples. Moreover, no synergistic effect with ionizing radiation has been

observed. A slight but significant decrease of cell proliferation was evident in ELFMFs

treated samples and samples subjected to the combined exposure.

 

Svedenstal BM, Johanson KJ, Mild KH. DNA damage induced in brain cells of

CBA mice exposed to magnetic fields. In Vivo. 13(6):551-552, 1999. (E)

DNA migration, using single cell gel electrophoresis (comet assay), was studied on brain

cells of CBA mice exposed continuously to 50 Hz, 0.5 mT magnetic fields (MF) for 2

hrs, 5 days or 14 days. No differences were observed in the groups MF-exposed for 2 hrs

and 5 days compared with controls. However, in the group exposed to MF for 14 days, a

significantly extended cell DNA migration was observed (0.02 < p < 0.05). These

changes together with results from previous studies indicate that magnetic fields may

have genotoxic effects in brain cells.

 

Testa A, Cordelli E, Stronati L, Marino C, Lovisolo GA, Fresegna AM, Conti D,

Villani P. Evaluation of genotoxic effect of low level 50 Hz magnetic fields on human

blood cells using different cytogenetic assays. Bioelectromagnetics. 25(8):613-619,

2004. (NE)

The question whether extremely low frequency magnetic fields (ELFMFs) may

contribute to mutagenesis or carcinogenesis is of current interest. In order to evaluate the

possible genotoxic effects of ELFMFs, human blood cells from four donors were exposed

in vitro for 48 h to 50 Hz, 1 mT uniform magnetic field generated by a Helmholtz coil

system. Comet assay (SCGE), sister chromatid exchanges (SCE), chromosome

aberrations (CAs), and micronucleus (MN) test were used to assess the DNA damage.

ELF pretreated cells were also irradiated with 1 Gy of X-ray to investigate the possible

combined effect of ELFMFs and ionizing radiation. Furthermore, nuclear division index

(NDI) and proliferation index (PRI) were evaluated. Results do not evidence any DNA

damage induced by ELFMF exposure or any effect on cell proliferation. Data obtained

from the combined exposure to ELFMFs and ionizing radiation do not suggest any

synergistic or antagonistic effect.

 

Villarini M, Moretti M, Scassellati-Sforzolini G, Boccioli B, Pasquini R. Effects of

co-exposure to extremely low frequency (50 Hz) magnetic fields and xenobiotics

determined in vitro by the alkaline comet assay. Sci Total Environ. 361(1-3):208-219,

2006. (E)

In the present study, we used human peripheral blood leukocytes from 4 different donors,

to investigate in vitro the possible genotoxic and/or co-genotoxic activity of extremely

low frequency magnetic fields (ELF-MF) at 3 mT intensity. Two model mutagens were

used to study the possible interaction between ELF-MF and xenobiotics: N-methyl-N'-

nitro-N-nitrosoguanidine (MNNG) and 4-nitroquinoline N-oxide (4NQO). Primary DNA

damage was evaluated by the alkaline single-cell microgel-electrophoresis ("comet")

assay. Control cells (leukocytes not exposed to ELF-MF, nor treated with genotoxins)

from the different blood donors showed a comparable level of basal DNA damage,

whereas the contribution of individual susceptibility toward ELF-MF and the tested

genotoxic compounds led to differences in the extent of DNA damage observed

following exposure to the genotoxins, both in the presence and in the absence of an

applied ELF-MF. A 3 mT ELF-MF alone was unable to cause direct primary DNA

damage. In leukocytes exposed to ELF-MF and genotoxins, the extent of MNNG-induced

DNA damage increased with exposure duration compared to sham-exposed cells. The

opposite was observed in cells treated with 4NQO. In this case the extent of 4NQOinduced DNA damage was somewhat reduced in leukocytes exposed to ELF-MF

compared to sham-exposed cells. Moreover, in cells exposed to ELF-MF an increased

concentration of GSH was always observed, compared to sham-exposed cells. Since

following GSH conjugation the genotoxic pattern of MNNG and 4NQO is quite different,

an influence of ELF-MF on the activity of the enzyme involved in the synthesis of GSH

leading to different activation/deactivation of the model mutagens used was hypothesized

to explain the different trends observed in MNNG and 4NQO genotoxic activity in the

presence of an applied ELF-MF. The possibility that ELF-MF might interfere with the

genotoxic activity of xenobiotics has important implications, since human populations are

likely to be exposed to a variety of genotoxic agents concomitantly with exposure to this

type of physical agent.

 

Williams PA, Ingebretsen RJ, Dawson RJ. 14.6 mT ELF magnetic field exposure

yields no DNA breaks in model system Salmonella, but provides evidence of heat stress

protection. Bioelectromagnetics. 27(6):445-450, 2006. (NE)

In this study, we demonstrate that common extremely low frequency magnetic field (MF)

exposure does not cause DNA breaks in this Salmonella test system. The data does,

however, provide evidence that MF exposure induces protection from heat stress.

Bacterial cultures were exposed to MF (14.6 mT 60 Hz field, cycled 5 min on, 10 min off

for 4 h) and a temperature-matched control. Double- and single-stranded DNA breaks

were assayed using a recombination event counter. After MF or control exposure they

were grown on indicator plates from which recombination events can be quantified and

the frequency of DNA strand breaks deduced. The effect of MF was also monitored using

a recombination-deficient mutant (recA). The results showed no significant increase in

recombination events and strand breaks due to MF. Evidence of heat stress protection

was determined using a cell viability assay that compared the survival rates of MF

exposed and control cells after the administration of a 10 min 53 degrees C heat stress.

The control cells exhibited nine times more cell mortality than the MF exposed cells.

This Salmonella system provides many mutants and genetic tools for further investigation

of this phenomenon.

 

Winker R, Ivancsits S, Pilger A, Adlkofer F, Rudiger HW. Chromosomal damage in

human diploid fibroblasts by intermittent exposure to extremely low-frequency

electromagnetic fields. Mutat Res. 585(1-2):43-49, 2005. (E)

Environmental exposure to extremely low-frequency electromagnetic fields (ELF-EMFs)

has been implicated in the development of cancer in humans. An important basis for

assessing a potential cancer risk due to ELF-EMF exposure is knowledge of biological

effects on human cells at the chromosomal level. Therefore, we investigated in the

present study the effect of intermittent ELF electromagnetic fields (50 Hz, sinusoidal,

5'field-on/10'field-off, 2-24 h, 1 mT) on the induction of micronuclei (MN) and

chromosomal aberrations in cultured human fibroblasts. ELF-EMF radiation resulted in a

time-dependent increase of micronuclei, which became significant after 10 h of

intermittent exposure at a flux density of 1 mT. After approximately 15 h a constant level

of micronuclei of about three times the basal level was reached. In addition,

chromosomal aberrations were increased up to 10-fold above basal levels. Our data

strongly indicate a clastogenic potential of intermittent low-frequency electromagnetic

fields, which may lead to considerable chromosomal damage in dividing cells.

 

Wolf FI, Torsello A, Tedesco B, Fasanella S, Boninsegna A, D'Ascenzo M, Grassi C,

Azzena GB, Cittadini A. 50-Hz extremely low frequency electromagnetic fields

enhance cell proliferation and DNA damage: possible involvement of a redox

mechanism. Biochim Biophys Acta. 1743(1-2):120-129, 2005. (E)

HL-60 leukemia cells, Rat-1 fibroblasts and WI-38 diploid fibroblasts were exposed for

24-72 h to 0.5-1.0-mT 50-Hz extremely low frequency electromagnetic field (ELF-EMF).

This treatment induced a dose-dependent increase in the proliferation rate of all cell

types, namely about 30% increase of cell proliferation after 72-h exposure to 1.0 mT.

This was accompanied by increased percentage of cells in the S-phase after 12- and 48-h

exposure. The ability of ELF-EMF to induce DNA damage was also investigated by

measuring DNA strand breaks. A dose-dependent increase in DNA damage was observed

in all cell lines, with two peaks occurring at 24 and 72 h. A similar pattern of DNA

damage was observed by measuring formation of 8-OHdG adducts. The effects of ELFEMF on cell proliferation and DNA damage were prevented by pretreatment of cells with an antioxidant like alpha-tocopherol, suggesting that redox reactions were involved.

Accordingly, Rat-1 fibroblasts that had been exposed to ELF-EMF for 3 or 24 h exhibited

a significant increase in dichlorofluorescein-detectable reactive oxygen species, which

was blunted by alpha-tocopherol pretreatment. Cells exposed to ELF-EMF and examined

as early as 6 h after treatment initiation also exhibited modifications of NF kappa Brelated proteins (p65-p50 and I kappa B alpha), which were suggestive of increased

formation of p65-p50 or p65-p65 active forms, a process usually attributed to redox

reactions. These results suggest that ELF-EMF influence proliferation and DNA damage

in both normal and tumor cells through the action of free radical species. This

information may be of value for appraising the pathophysiologic consequences of an

exposure to ELF-EMF.

 

Yaguchi H, Yoshida M, Ejima Y, Miyakoshi J. Effect of high-density extremely low

frequency magnetic field on sister chromatid exchanges in mouse m5S cells. Mutat

Res. 440(2):189-194, 1999. (E)

The induction of sister chromatid exchanges (SCEs) was evaluated in the cultured mouse

m5S cells after exposure to extremely low frequency magnetic field (ELFMF; 5, 50 and

400 mT). Exposure to 5 mT and 50 mT ELFMF led to a very small increase in the

frequency of SCEs, but no significant difference was observed between exposed and

unexposed control cells. The cells exposed to 400 mT ELFMF exhibited a significant

elevation of the SCE frequencies. There was no significant difference between data from

treatments with mitomycin-C (MMC) alone and from combined treatments of MMC plus

ELFMF (400 mT) at any MMC concentrations from 4 to 40 nM. These results suggest

that exposure to highest-density ELFMF of 400 mT may induce DNA damage, resulting

in an elevation of the SCE frequencies. We suppose that there may be a threshold for the

elevation of the SCE frequencies, that is at least over the magnetic density of 50 mT.

 

Yokus B, Cakir DU, Akdag MZ, Sert C, Mete N. Oxidative DNA damage in rats

exposed to extremely low frequency electro magnetic fields. Free Radic Res.

39(3):317-323, 2005. (E)

Extremely low frequency (ELF) electromagnetic field (EMF) is thought to prolong the

life of free radicals and can act as a promoter or co-promoter of cancer. 8-hydroxy-2'-

deoxyguanosine (8OHdG) is one of the predominant forms of radical-induced lesions to

DNA and is a potential tool to asses the cancer risk. We examined the effects of

extremely low frequency electro magnetic field (ELF-EMF) (50 Hz, 0.97 mT) on 8OHdG

levels in DNA and thiobarbituric acid reactive substances (TBARS) in plasma. To

examine the possible time-dependent changes resulting from magnetic field, 8OHdG and

TBARS were quantitated at 50 and 100 days. Our results showed that the exposure to

ELF-EMF induced oxidative DNA damage and lipid peroxidation (LPO). The 8OHdG

levels of exposed group (4.39+/-0.88 and 5.29+/-1.16 8OHdG/dG.10(5), respectively)

were significantly higher than sham group at 50 and 100 days (3.02+/-0.63 and 3.46+/-

0.38 8OHdG/dG.10(5)) (p<0.001, p<0.001). The higher TBARS levels were also

detected in the exposure group both on 50 and 100 days (p<0.001, p<0.001). In addition,

the extent of DNA damage and LPO would depend on the exposure time (p<0.05 and

p<0.05). Our data may have important implications for the long-term exposure to ELFEMF which may cause oxidative DNA damage.

 

Zmyslony M, Palus J, Jajte J, Dziubaltowska E, Rajkowska E. DNA damage in rat

lymphocytes treated in vitro with iron cations and exposed to 7 mT magnetic fields

(static or 50 Hz). Mutat Res. 453(1):89-96, 2000. (E)

The present study was undertaken to verify a hypothesis that exposure of the cells to

static or 50 Hz magnetic fields (MF) and simultaneous treatment with a known oxidant,

ferrous chloride, may affect the oxidative deterioration of DNA molecules.The comet

assay was chosen for the assessment of DNA damage. The experiments were performed

on isolated rat lymphocytes incubated for 3h in Helmholtz coils at 7 mT static or 50 Hz

MF. During MF exposure, part of the cell samples were incubated with 0.01 microM

H(2)O(2) and another one with 10 microg/ml FeCl(2,) the rest serving as

controls.Lymphocyte exposure to MF at 7 mT did not increase the number of cells with

DNA damage in the comet assay. Incubation of lymphocytes with 10 microg/ml FeCl(2)

did not produce a detectable damage of DNA either. However, when the FeCl(2)-

incubated lymphocytes were simultaneously exposed to 7 mT MF, the number of

damaged cells was significantly increased and reached about 20% for static MF and 15%

for power frequency MF. In the control samples about 97% of the cells did not have any

DNA damage.It is not possible at present to offer a reasonable explanation for the

findings of this investigation - the high increase in the number of lymphocytes showing

symptoms of DNA damage in the comet assay, following simultaneous exposure to the

combination of two non-cytotoxic factors -10 microg/ml FeCl(2) and 7 mT MF. In view

of the obtained results we can only hypothesise that under the influence of simultaneous

exposure to FeCl(2) and static or 50 Hz MF, the number of reactive oxygen species

generated by iron cations may increase substantially. Further studies will be necessary to

confirm this hypothesis and define the biological significance of the observed effect.

 

Zmyslony M, Palus J, Dziubaltowska E, Politanski P, Mamrot P, Rajkowska E,

Kamedula M. Effects of in vitro exposure to power frequency magnetic fields on

UV-induced DNA damage of rat lymphocytes. Bioelectromagnetics. 25(7):560-562,

2004. (E)

The mechanisms of biological effects of 50/60 Hz (power frequency) magnetic fields

(MF) are still poorly understood. There are a number of studies indicating that MF affect

biochemical processes in which free radicals are involved, such as the biological objects'

response to ultraviolet radiation (UVA). Therefore, the present study was aimed to assess

the effect of 50 Hz MFs on the oxidative deterioration of DNA in rat lymphocytes

irradiated in vitro by UVA. UVA radiation (150 J/m2) was applied for 5 min for all

groups and 50 Hz MF (40 microT rms) exposure was applied for some of the groups for 5

or 60 min. The level of DNA damage was assessed using the alkaline comet assay, the

fluorescence microscope, and image analysis. It has been found that the 1 h exposure to

MF caused an evident increase in all parameters consistent with damaged DNA. This

suggest that MF affects the radical pairs generated during the oxidative or enzymatic

processes of DNA repair.

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