Unknown authors · 2000
The article reviews reports of skin and heart symptoms in people exposed to video display terminals. Recent studies cited indicate that electromagnetic fields can affect mast cells and dendritic cells and may degranulate them. The model suggests that degranulation of mast cells and dendritic cells releases histamine, which can cause local erythema, edema, itch, and pain, and somatostatin, which may produce sensations of ongoing inflammation and sensitivity to ordinary light.
Unknown authors · 2000
The study was a case-control study of women living within 300 meters of transmission lines in Sweden. For occupational exposure over 0.25 microtesla, the relative risk of breast cancer was 1.0 with a 96% confidence interval of 0.6 to 1.7. Women under 50 had a relative risk of 1.5, and those with estrogen receptor-positive tumors had a relative risk of 3.2, though confidence intervals were wide.
Unknown authors · 2000
Researchers investigated whether exposure to 60-Hz sinusoidal magnetic fields (0.3-1.2 G for 3-72 h) would cause proliferation of human astrocytoma cells. Sixty-Hertz magnetic fields caused a time- and dose-dependent increase in proliferation of astrocytoma cells, measured by (3)H-thymidine incorporation and by flow cytometry, and strongly potentiated the effect of two agonists. However, magnetic fields had no effect on DNA synthesis of rat cortical astrocytes, which are similar nontransformed cells. A protein kinase C inhibitor and down-regulation of protein kinase C inhibited the effect of magnetic fields on basal and agonist-stimulated thymidine incorporation.
Unknown authors · 2000
Researchers measured personal magnetic field exposure, ambient light, and excretion of the melatonin metabolite 6-hydroxymelatonin sulfate over three consecutive workdays in electric utility workers. Men working more than two hours daily in substation and three-phase environments showed a magnetic field-dependent reduction in adjusted mean nocturnal and post-work metabolite levels, while those working two hours or less showed no effect. No changes were observed in men working in single-phase environments.
Unknown authors · 2000
Researchers examined the effect of 50 mT, 60 Hz ELFMF on heat-induced HSP-70 expression in HL60RG cells. Exposure to 50 mT ELFMF alone did not increase HSP-70 production. Combined exposure to 50 mT ELFMF and mild heat at 40°C and 42°C suppressed heat-induced HSP-70 expression. This suppression required simultaneous exposure for more than 5 hours. Lower magnetic densities of 5 mT and 0.5 mT did not suppress HSP-70.
Unknown authors · 2000
The researchers conducted a large case-control study of childhood acute lymphoblastic leukemia and electric-power-line wire codes. They examined internal evidence to assess whether selection bias or confounding affected the findings. Excluding 107 partial participants increased the odds ratio for very high current configurations by 23%, and similar but slightly smaller increases were seen with direct magnetic field measurements. Partial participants had lower socioeconomic status than full participants, suggesting possible selection bias, while confounding adjustments changed the odds ratio by less than 8% individually and at most 15% simultaneously.
Unknown authors · 2000
Researchers conducted a nested case-control study of male electric utility workers examining suicide mortality in relation to estimated exposure to extremely low frequency electromagnetic fields. The study included 536 suicide deaths and 5,348 controls, with exposure classified by jobs with increased magnetic field exposure and cumulative exposure indices from a measurement survey. Suicide mortality was increased for work in exposed jobs and with magnetic field exposure indices, with increased odds ratios for electricians (OR 2.18, 95% CI 1.25 to 3.80) and linemen (OR 1.59, 95% CI 1.18 to 2.14) and a decreased odds ratio for power plant operators (OR 0.67, 95% CI 0.33 to 1.40).
Unknown authors · 2000
Unknown authors · 2000
Unknown authors · 2000
The researcher studied the incidence of central nervous system diseases in 30,631 persons employed in Danish utility companies between 1900 and 1993, linked the cohort to the Danish National Register of Patients and compared cases from 1978 to 1993 with general population rates, and fitted a multiplicative Poisson regression model to estimated 50-Hz electromagnetic field exposure levels. Overall there was an increase in risk for senile dementia and motor neuron diseases combined, while Parkinson disease, Alzheimer disease, and other central nervous system diseases were essentially unrelated to exposure. A decreased risk of epilepsy compared with the general population probably reflects a healthy worker effect, but internal comparisons showed an increased risk of epilepsy.
Unknown authors · 2000
Researchers from Löscher's group in Germany exposed Sprague-Dawley rats to 50-Hz magnetic fields at microtesla flux densities for 13 or 27 weeks using a DMBA breast cancer model. The exposure significantly increased mammary tumor development and growth in those experiments. A similar study by Battelle in the United States did not replicate the effect.
Unknown authors · 2000
Researchers conducted a pooled analysis based on individual records from nine studies. The analysis included 3203 children with leukaemia and 10 338 control children with estimated residential magnetic field exposures levels < 0.4 μT, and 44 children with leukaemia and 62 control children with exposures ≥ 0.4 μT. For exposures ≥ 0.4 μT the estimated summary relative risk was 2.00 (1.27–3.13), P value = 0.002, while for exposures < 0.4 μT risk estimates were near the no effect level. Adjustment for potential confounding variables did not appreciably change the results. No evidence was found for a wire-code paradox; the highest wire code category showed a relative risk of 1.24 (0.82–1.87).
Unknown authors · 2000
Researchers conducted a case-cohort analysis using a refined magnetic field job-exposure matrix, selecting 164 leukemia deaths, 145 brain cancer deaths, and a random subcohort of 800 men from the original cohort. Magnetic field exposure was unrelated to leukemia mortality. Brain cancer mortality was positively associated with magnetic field exposure, with risk ratios of 1.8 and 2.5 in the highest cumulative and average exposure categories. Improvements in exposure assignment through job title regrouping had little impact on the measured associations for either cancer.
Unknown authors · 2000
Unknown authors · 2000
Researchers cultured mouse pre-antral follicles for 5 days and exposed them to pulsed ELF-EMF at 33 Hz or 50 Hz. ELF-EMF did not affect follicular growth over 3 days, but on day 5 the 33 Hz exposure significantly reduced growth compared to controls, while 50 Hz did not. ELF-EMF severely impaired antrum formation at both frequencies, with control follicles forming antral cavities at 79% versus 30% at 33 Hz and 51.6% at 50 Hz. Oocytes from exposed follicles showed a reduced ability to resume meiotic maturation compared to controls.
Schilling CJ · 2000
The study investigated effects of exposure to very high frequency radiofrequency radiation on six antenna engineers in two separate incidents. The first incident occurred in 1995 and the second in 1996. Six men were likely accidentally exposed to high levels of VHF radiofrequency radiation at 100 MHz while working on transmission masts, with four men in one incident and two in another. They experienced symptoms and signs including headache, paresthesiae, diarrhea, malaise, and lassitude. The condition of four men, two from each incident likely to have had the highest exposure, showed no significant improvement.
Wagner P et al. · 2000
Researchers aimed to investigate human sleep EEG under pulsed radio frequency electromagnetic fields using polysomnographies with submaximal high power flux densities. They applied a submaximal power flux density of 50 W/m(2). All-night polysomnographies were recorded from 20 healthy male subjects with and without exposure to a circularly polarized EMF at 900 MHz pulsed at 217 Hz with 577 microsecond pulse duration. The results showed no significant effect of the field application on conventional sleep parameters or sleep EEG power spectra.
Tsurita G, Nagawa H, Ueno S, Watanabe S, Taki M, · 2000
Male Sprague-Dawley rats were exposed to a 1439 MHz TDMA field. Exposure lasted one hour a day for two or four weeks. The study assessed blood-brain barrier permeability, cerebellar morphology, and body mass.
Sienkiewicz ZJ et al. · 2000
Schuz J, Mann S · 2000
Researchers conducted a feasibility study to test whether short-term electric field measurements, calculated field strengths, or distance from base stations could serve as exposure metrics for radiowaves. Measurements showed electric field strengths from base stations between 0.012 and 0.343 V/m, though broadcast radio and television transmitters often produced stronger signals. The study concluded that population-level studies on health effects are not feasible because no valid metric exists for estimating historical exposures.
Reeves GI · 2000
Researchers reviewed medical records of 34 patients with confirmed RFR overexposure exceeding permitted limits to detect clinical or laboratory alterations correlated with power density or power density times exposure time. A sensation of warmth was positively associated with power density, while a negative correlation was observed between an abnormal tissue destruction screen and power density. Sophisticated neurological tests in 23 patients and extensive psychometric and psychological exams in 30 patients revealed no neurological or ophthalmologic findings attributable to RFR.
Pakhomov AG et al. · 2000
Researchers compared extremely high power microwave pulses (EHPP) with low power pulses (LPP) at 9.2 GHz on isolated, spontaneously beating frog heart slices. Both exposure types produced the same temperature rise because EHPP train duration and average power were matched to LPP. The effects were proportional to heating, fully reversible, and reproducible with no delayed or irreversible effects observed. A single EHPP train or LPP immediately decreased the inter-beat interval in most cases. Temporary arrest of beats could be observed when microwave heating exceeded physiologically tolerable limits, regardless of exposure type.
Oftedal G, Wilen J, Sandstrom M, Mild KH · 2000
Thirty-one percent of Norwegian respondents and 13% of Swedish respondents reported at least one symptom associated with mobile phone use. The most common symptoms were sensations of warmth on or behind the ear, burning sensations in the facial skin, and headaches. Most symptoms began during or within half an hour after the call and lasted for up to two hours. Relatively few participants consulted a physician or took sick leave, but about 45% of those with symptoms took steps to reduce them, and the authors concluded that the results suggest awareness of the symptoms but not necessarily a serious health problem.
Muscat JE et al. · 2000
Researchers conducted a case-control study in five US academic medical centers between 1994 and 1998 using a structured questionnaire, enrolling 469 adults with primary brain cancer and 422 matched controls. The median monthly hours of use were 2.5 for cases and 2.2 for controls, and the multivariate odds ratio for regular use was 0.85 (95% CI, 0.6-1.2). No association was observed according to duration of use (P = .54), and cerebral tumors occurred more often on the same side as phone use (26 vs 15 cases; P = .06) while temporal lobe tumors showed the opposite pattern (9 vs 5 cases; P = .33).
Morgan RW et al. · 2000
Researchers conducted a large cohort mortality study among 195,775 Motorola employees from 1976 to 1996, classifying workers into high, moderate, low, and background radiofrequency exposure groups. Standardized mortality ratios for radiofrequency-exposed workers were 0.53 for brain cancers and 0.54 for lymphomas and leukemias. Internal rate ratios were near 1.0 for brain cancers and below 1.0 for lymphomas and leukemias, with no increased risk seen with longer exposure duration or latency. The findings were consistent across different exposure classifications and did not support an association between occupational radiofrequency exposure and these cancers.
