Unknown authors · 2004
The authors review studies documenting melatonin's influence on the activity and expression of glutathione peroxidase, superoxide dismutases, and catalase. Melatonin has been shown to possess genomic actions that regulate the expression of several genes. Melatonin also influences both antioxidant enzyme activity and cellular mRNA levels for these enzymes. The review also analyzes possible mechanisms by which melatonin regulates these enzymes.
Unknown authors · 2004
Researchers compared two Sprague-Dawley substrains, SD1 and SD2, for magnetic field effects on cell proliferation, susceptibility to DMBA-induced mammary cancer, and tumor development in the DMBA model. The SD1 substrain was considered MF-sensitive and was compared with SD2 from the same breeder. Magnetic field exposure significantly increased mammary tumor development and growth in SD1 rats but not in SD2 rats. No enhanced cell proliferation was determined after magnetic field exposure in SD2 rats, unlike in SD1 rats. The researchers concluded that genetic background plays a pivotal role in magnetic field exposure effects.
Unknown authors · 2004
Researchers conducted a population-based case-control study in Norway to assess residential and occupational exposure to 50-Hz magnetic fields and breast cancer risk. Cases of breast cancer diagnosed from 1980 to 1996 were identified in a cohort of women living near a high-voltage power line, and each case was matched to two controls by year of birth, municipality, and cohort entry year. Residential exposure was calculated from the magnetic fields generated by the power lines before diagnosis, while occupational exposure was based on an exposure matrix. Women with residential exposure had an odds ratio of 1.58 (95% CI: 1.30, 1.92) for breast cancer, whereas the highest occupational exposure yielded an odds ratio of 1.13 (95% CI: 0.91, 1.40).
Unknown authors · 2004
Ionizing radiation has been the subject of intense epidemiological investigation. The Life Span Study of atomic bomb survivors is the predominant source of evidence, supplemented by studies of medical, occupational, and environmental exposures. Notable studied groups include underground miners exposed to radon, patients receiving therapeutic radiation, and nuclear weapons program workers in the former USSR. Low-level exposure risk is contentious but evidence suggests increased risk approximately proportional to dose. Ultraviolet radiation is established as a cause of skin cancer, while evidence for mobile phone or power line radiation is not convincing, though a childhood leukemia link to extremely low-frequency fields cannot be dismissed.
Unknown authors · 2004
The authors conducted an extensive literature review and propose that ELF EMF exposure increases free radical levels. They suggest EMF might induce an activated state such as phagocytosis, enhancing free radical release and leading to genotoxic events. The proposed mechanisms include direct activation of macrophages leading to phagocytosis and free radical production, and direct stimulation of free radical production by EMF-induced macrophage activation. They also propose that EMF increases the lifetime of free radicals causing persistently elevated concentrations, and that long-term exposure leads to chronically increased free radicals that inhibit melatonin effects. Taken together, these reactions could lead to higher DNA damage incidence and increased tumor risk.
Unknown authors · 2004
Researchers reviewed Swedish melanoma incidence, mortality, charter travel statistics, and FM broadcasting network expansion across all counties. Melanoma trend break occurred in 1955, while increased charter sun travel began seven years later. Counties with delayed FM network rollout had stable melanoma mortality during the delay period.
Unknown authors · 2004
Researchers distributed health questionnaires from June 2001 to people who complained of symptoms they ascribed to electromagnetic field exposure. Within one year, 429 questionnaires were returned and 394 persons reported symptoms, with an average age of 51.0 years and 57% female. The most common symptoms were sleep disorders (58%), headaches (41%), nervousness or distress (19%), fatigue (18%), and concentration difficulties (16%). Participants most often attributed symptoms to mobile phone base stations (74%), mobile phones (36%), cordless phones (29%), and power lines (27%), but no distinct symptom pattern was linked to a specific source.
Unknown authors · 2004
No increased risks were found for leukemia, brain tumors, or breast cancer among the utility workers. Utility workers showed a significantly increased ALS mortality rate that rose with longer employment and higher EMF exposure. The mobile phone cohort showed no increased risk for brain tumors, acoustic neuroma, salivary gland tumors, or leukemia.
Unknown authors · 2004
Unknown authors · 2004
Researchers exposed cerebral cortical neurons from postnatal rats to low-intensity 900MHz continuous microwave electromagnetic fields at 9mW/cm2 with a SAR of 3.22mW/g for 2 hours per day over 4 or 5 consecutive days and also for 12 hours at a time. They measured cytochrome oxidase activity as a marker of energy metabolism. Compared to sham-exposed neurons, cytochrome oxidase activity decreased significantly in neurons exposed for 2 hours per day and in those exposed for 12 hours (P < 0.001).
Tahvanainen K et al. · 2004
Researchers conducted a randomized, double-blind, placebo-controlled crossover trial with 32 healthy subjects exposed to 900 MHz (2 W) and 1800 MHz (1 W) cellular phone signals and sham exposure in separate sessions. Arterial blood pressure and heart rate did not change significantly during or after the 35-minute RF exposures at either frequency compared to sham exposure. Blood pressure was measured with an arm cuff and heart rate was recorded during and after each 35-minute exposure session.
Sommer AM, Streckert J, Bitz AK, Hansen VW, Lerchl A · 2004
Survival rate and lymphoma incidence did not differ between exposed and sham-exposed mice. Exposed mice gained more weight than sham-exposed mice. The data do not support the hypothesis that 900 MHz fields are a significant risk factor for lymphoma in this genetically predisposed strain.
Sandrini L et al. · 2004
Researchers created a female dielectric anatomical model and compared power absorption in male and female models from 0.1 to 4 GHz. Whole-body-averaged SAR was higher in the female model, mainly due to a thicker subcutaneous fat layer. Maximum 1 g and 10 g averaged SAR did not depend on gender because it occurs in regions without subcutaneous fat.
Samkange-Zeeb F, Berg G, Blettner M · 2004
Researchers compared self-reported cellular phone use from 68 participants with network provider records over three months. The correlation for number of calls per day was good at r=0.62, while the correlation for average call duration was moderate at r=0.34. Cumulative phone use showed a correlation of r=0.56.
Ramundo-Orlando A, Liberti M, Mossa G, D'Inzeo G. · 2004
Enzyme activity decreased only at 5.6 W/kg, with no response at lower SAR values. When using deglycated ascorbate oxidase without oligosaccharide chains, microwave irradiation caused no enzyme activity changes, indicating the chains are necessary for the effect. Catalytic properties of both enzyme forms were unaffected by microwave exposure in solution or in liposomes, ruling out enzyme conformational changes as a mechanism. The authors concluded that oligosaccharide chains of ascorbate oxidase are critical for microwave effects on lipid membranes.
Park SK,Ha M, Im H-J · 2004
Researchers compared cancer mortality in ten areas with AM radio towers over 100 kW to control areas without towers using Korean death certificates from 1994-1995. All-cancer mortality was significantly higher in exposed areas with a mortality rate ratio of 1.29 (95% CI 1.12-1.49). Leukemia mortality was elevated in exposed areas (MRR 1.70, 95% CI 0.84-3.45), with the highest ratios in children aged 0-14 (MRR 2.29) and young adults aged 15-29 (MRR 2.44). Significant increases were seen at several power levels (100 kW, 250 kW, 500 kW) but without a consistent increasing trend across power groups. The authors concluded that the findings do not prove causation but suggest further analytical studies are needed.
Ono T et al. · 2004
A possible mutagenic effect of 2.45 GHz radiofrequency exposure was examined using lacZ-transgenic MutaTM mice. Offspring were exposed in utero for 16 hours a day from embryonic day 0 to 15 and examined at 10 weeks of age. Mutation frequencies at the lacZ gene in spleen, liver, brain, and testis were similar to those in non-exposed mice. Sequencing of mutant DNAs showed no appreciable difference in mutation quality between exposed and non-exposed samples.
Monnery PM, Srouji EI, Bartlett J · 2004
Researchers recruited 12 volunteers with normal hearing and measured their otoacoustic emissions. The volunteers were exposed to a mobile telephone placed over the mastoid process during receive and transmit modes. There was no change in the trace signature and no statistically significant change in trace figures. The researchers concluded that PEMF from mobile phones has no measurable effect on outer hair cell function during use.
Lonn S, Ahlbom A, Hall P, Feychting M. · 2004
In this population-based case-control study, researchers identified all cases aged 20 to 69 years diagnosed with acoustic neuroma during 1999 to 2002 in certain parts of Sweden. Controls were randomly selected from the study base, stratified on age, sex, and residential area. The overall odds ratio for acoustic neuroma associated with regular mobile phone use was 1.0 with a 95% confidence interval of 0.6 to 1.5. Ten years after the start of mobile phone use the relative risk increased to 1.9 (0.9-4.1), and for tumors on the same side of the head as the phone was normally used, the relative risk was 3.9 (1.6-9.5). The researchers concluded that there was no increased risk for short-term use but suggested an increased risk for at least 10 years' duration.
Krause CM et al. · 2004
Researchers conducted a double-blind study in which subjects performed a memory task with and without exposure to a digital 902 MHz field. All eight significant EEG changes from the earlier study were not significant in this replication. The effect of EMF on incorrect answers was inconsistent, with a significant increase in errors observed in this study but not in the earlier one.
Jokela K, Puranen L, Sihvonen AP. · 2004
Researchers assessed magnetic field exposure from battery currents of digital mobile phones using ICNIRP guidelines and two evaluation approaches. The ICNIRP exposure ratio based on current density ranged from 0.04 to 0.14 for the weighted peak approach and from 0.08 to 0.27 for the multiple-frequency rule. The exposure did not exceed guidelines, and no biological data indicate health concerns from magnetic field pulses.
Hutter HP, Moshammer H, Wallner P, Kundi M. · 2004
Researchers surveyed neighbors of cell towers (n = 123, response rate approx. 48%) and medical students (n = 366) about environmental health risks including mobile telecommunication. Neighbors rated health risks for both mobile phones and cell towers higher than students did. The magnitude of perceived risks resembled that of other ubiquitous exposures like traffic noise and air pollution.
Hinrichs H, Heinze HJ. · 2004
Researchers investigated potential effects of GSM 1800 electromagnetic fields on verbal memory encoding by recording event-related magnetic fields from the brain during subsequent memory retrieval. Twelve normal subjects each completed two experimental sessions, one with EMF exposure during the study phase and one without. Exposure to EMF changed an early (350-400 ms) task-specific component of the event-related magnetic field, indicating interference with item encoding. Behavioral measures were not significantly affected.
Hardell L et al. · 2004
Researchers investigated the association between cellular or cordless telephone use and salivary gland tumor risk using cases from six regional cancer registries in Sweden. The study included 267 participating cases and 1053 controls with four controls matched for sex and age per case. No significantly increased risk was found overall, with odds ratios of 0.92 for analogue phones, 1.01 for digital phones, and 0.99 for cordless phones. Similar results were found for different salivary gland localizations and no effect of tumor induction period or latency was seen. The authors noted the study does not permit conclusions for long-term heavy use.
Haarala C et al. · 2004
Researchers studied the effects of a 902 MHz mobile phone EMF on human short term memory using a double blind, multi-centre design. Sixty-four subjects in two laboratories performed an n-back task with memory loads of 0 to 3 items under both EMF and sham exposure. The EMF had no effect on reaction times or accuracy, and performance did not differ between the two laboratories.
