Unknown authors · 1997
From an initial questionnaire study among 4943 office workers, 163 VDT workers were selected for a case referent study of facial skin symptoms. The data comprise a self-administered questionnaire filled out by 149 subjects and interviews with representatives of the organizations concerned. Psychosocial conditions, especially lack of social support from co-workers, were associated with an increased risk of reporting skin symptoms. Stratification by sex showed that the associations between some psychosocial factors and health differed between men and women. The results indicate that there might be an interaction between psychosocial factors and electric fields in the workplace which increases the risk of reporting skin symptoms.
Unknown authors · 1997
Researchers used data from 12,063 Finnish twins who completed a depression inventory in 1990. Exposure was assessed using 20-year histories of distance to and calculated magnetic fields from 110- to 400-kV overhead power lines. Adjusted mean depression scores did not differ by exposure level. The risk of severe depression was 4.7 times higher for those living within 100 meters of a high-voltage line, though this was based on small numbers.
Vollrath L, Spessert R, Kratzsch T, Keiner M, Hollmann H · 1997
Researchers exposed male and female Sprague-Dawley rats and Djungarian hamsters to 900 MHz electromagnetic fields at 0.1 to 0.6 mW/cm2, continuous or pulsed at 217 Hz, for 15 min to 6 h. At day or night had no notable short-term effect on pineal melatonin synthesis in male and female Sprague-Dawley rats and Djungarian hamsters. Pineal synaptic ribbon profile numbers (studied in rats only) were likewise not affected The 900 MHz electromagnetic fields, unpulsed or pulsed at 217 Hz, as applied in the present study, have no short-term effect on the mammalian pineal gland.
Vijayalaxmi et al. · 1997
C3H/HeJ mice prone to mammary tumors were exposed to 2450 MHz RF radiation at 1.0 W/kg for 20 hours per day, 7 days a week, over 18 months, with sham-exposed controls and positive controls treated with mitomycin C. The incidence of micronuclei in peripheral blood and bone marrow did not differ significantly between RF-exposed and sham-exposed groups. Positive controls treated with mitomycin C showed significantly elevated micronuclei frequencies. A separate analysis of mice that developed mammary tumors also found no significant differences in micronuclei frequency between exposure groups.
Vijayalaxmi, Mohan, N, Meltz, ML, Wittler, MA, · 1997
Stark KD, Krebs T, Altpeter E, Manz B, Griot C, Abelin T · 1997
Researchers conducted a pilot study comparing two dairy herds at 500 m and 4,000 m from a short-wave radio transmitter, monitoring five cows per farm for salivary melatonin over ten days. The average nightly field strength was 21-fold higher on the exposed farm (1.59 mA/m) than on the control farm (0.076 mA/m). No significant difference in melatonin was seen during the first two nights, but on the first night after the transmitter was turned back on following a three-day off period, melatonin concentration was significantly higher on the exposed farm (3.89 pg/ml, CI: 2.04, 7.41), indicating a two- to seven-fold increase.
Stagg RB, Thomas WJ, Jones RA, Adey WR · 1997
Researchers exposed transformed and normal rat glial cells to an 836.55 MHz packet-modulated RF field at power densities of 0.09, 0.9, and 9 mW/cm2, with SARs from 0.15 to 59 muW/g. Primary rat glial cells showed no significant differences in DNA synthesis between sham and RF-exposed conditions for either log-phase or serum-starved cultures. C6 glioma cells exposed at 5.9 muW/g SAR showed small but significant increases in thymidine incorporation in 38% of experiments. Growth curves showed no differences between sham and RF-exposed cultures for either cell type, and doubling times of C6 glioma cells did not differ significantly.
Sanmartin M et al. · 1997
Researchers tested 30 patients with eight different defibrillator models using three GSM mobile phones under continuous electrocardiographic monitoring. Phones were placed in close contact with the defibrillator can and precordium at two angles, and tested during calling, established contact for 15 seconds, and ringing, with the protocol repeated during pacing. No cases of electromagnetic interference were observed. One patient presented non-sustained ventricular tachycardia episodes during the tests that were detected by the defibrillator. These results suggest that electromagnetic interference by GSM mobile phones are not a probable cause of implantable defibrillators dysfunction.
Salford LG, Brun A, Persson BRR · 1997
Researchers used Fischer 344 rats of both sexes with implanted glioma cells (RG2 and N32) in a matched-pair design. Starting on day 5 after inoculation, rats were exposed for 7 hours a day, 5 days a week for 2–3 weeks to 915 MHz continuous or pulse-modulated microwaves. The study found no significant difference in tumour size between exposed and control animals. Tumour size was estimated as the volume of an ellipsoid after histopathological examination of all brains.
Safronova VG et al. · 1997
Ryan KL, Walters TJ, Tehrany MR, Lovelace JD, Jauchem JR · 1997
Researchers exposed three age groups of calorically restricted rats to 35 GHz microwaves until death while measuring temperature, heart rate, and mean arterial pressure. Before exposure, the age groups showed no significant differences in measured parameters. Microwave heating increased temperatures at all measured sites, but temperatures at death did not differ between age groups. Heart rate increased throughout exposure in a statistically identical manner across all age groups, and mean arterial pressure was initially well maintained before precipitously declining until death with no age-related difference. Respiration rate was not altered by microwave exposure in any group, and the exposure time required to induce death did not differ among age groups.
Roschke, J, Mann, K · 1997
Researchers tested 34 healthy men in a single-blind cross-over study with a 900 MHz GSM field at 0.05 mW/cm² for nearly 3.5 minutes. They measured spontaneous EEG from C3 and C4 under closed eyes and found no difference in spectral power density between active and inactive phone conditions.
Klug S, Hetscher M, Giles S, Kohlsmann S, Kramer K, · 1997
Researchers exposed 9.5-day-old rat embryos for up to 36 hours to radiofrequency electric and magnetic fields with modulation frequencies of 16, 60, and 120 Hz. The exposure included electric field strengths of 60 and 600 V/m, magnetic inductions of 0.2 and 2.0 microtesla, and specific absorption rates of 0.2, 1.0, and 5.0 W/kg. Neither the electric nor the magnetic fields interfered significantly with normal embryo growth and differentiation when assessed on day 11.5 using a scoring system, photographs, histology, and protein content.
Jauchem, JR, · 1997
The review examined cardiovascular changes in humans exposed to extremely-low-frequency electromagnetic fields and radiofrequency radiation. Most studies showed no acute effect of ELF EMFs on blood pressure, heart rate, or electrocardiogram waveform, though some reported subtle heart rate effects. Soviet reports from the 1960s linked long-term ELF EMF exposure to arrhythmias and tachycardia in switchyard workers, but Western studies did not confirm this. MRI-related RFR exposures were concluded not likely to cause adverse cardiovascular effects. Overall, no obvious cardiovascular hazards were found for exposures below current standards.
Ivaschuk OI et al. · 1997
Researchers exposed nerve growth factor-treated PC12 rat pheochromocytoma cells to a packet-modulated 836.55 MHz radiofrequency field at power densities of 0.09, 0.9, and 9 mW/cm2 for 20, 40, or 60 minutes, with an intermittent 20-minute on/off regimen. Sham-exposed cells served as controls, and c-fos and c-jun expression was measured by Northern blot analysis of total RNA. C-fos transcript levels did not change after 20 minutes at any intensity, while c-jun transcripts decreased by 38% only after 20 minutes at 9 mW/cm2.
Indulski JA, Makowiec-Dabrowska T, Zmyslony M, Siedlecka J · 1997
The authors reviewed epidemiological data on the relationship between reproductive disorders and electromagnetic field exposure from power lines, industrial devices, medical appliances, video display terminals, and household devices. The analyzed studies examined effects on female and male reproduction, including spontaneous abortion, stillbirth, premature birth, low birth weight, congenital malformations, and progeny gender proportion among occupationally exposed persons.
Gos, P, Eicher, B, Kohli, J, Heyer, WD · 1997
Researchers exposed exponentially growing Saccharomyces cerevisiae cells to electromagnetic fields from 41.682 GHz to 41.710 GHz in 2 MHz increments at power densities of 0.5 and 50 microW/cm2. Cell division was assessed by time-lapse photography using two identical chambers that allowed concurrent control and exposure experiments. Control experiments showed the cells were dividing at submaximal rates, ensuring that any increase or decrease in division rate could be observed. No consistently significant differences were found between exposed and unexposed cells across multiple independent experiment series.
Cain CD, Thomas DL, Adey WR · 1997
The study tested whether a TDMA-modulated RF field and the tumor promoter TPA together increase focus formation of transformed cells cocultured with parental C3H/10T1/2 murine fibroblasts. Cell cultures were exposed to an 836.55 MHz TDMA-modulated field at specific absorption rates of 0.15, 1.5, and 15 μW/g in a repeating cycle of 20 minutes on and 20 minutes off continuously for 28 days. RF exposure did not significantly alter TPA-induced focus formation at any of the tested exposure levels across multiple independent experiments.
Antonopoulos A, Eisenbrandt H, Obe G, · 1997
Human peripheral lymphocytes were incubated in the presence of high-frequency electromagnetic fields of 380, 900 and 1800 MHz. The measured endpoints were cell cycle progression and the frequencies of sister-chromatid exchanges. No differences between treated and control cultures could be found.
Malyapa RS et al. · 1997
Researchers exposed mouse C3H 10T1/2 fibroblasts and human glioblastoma U87MG cells to FMCW (835.62 MHz) and CDMA (847.74 MHz) radiation at 0.6 W/kg SAR for up to 24 hours. They used the alkaline comet assay to measure DNA damage. No significant differences were found between exposed cells and sham controls.
Malyapa RS et al. · 1997
Researchers used the alkaline comet assay to test whether 2450 MHz radiation causes DNA damage in cultured mammalian cells. Exponentially growing U87MG and C3H 10T1/2 cells were exposed to 2450 MHz CW radiation at SARs of 0.7 and 1.9 W/kg for durations of 2 h, 2 h followed by 4-h incubation, 4 h, and 24 h. No significant differences were observed between the test group and the controls after exposure.
Schilling, CJ · 1997
Violanti JM · 1997
The study examined statistical rate-ratios of accident characteristics between drivers with and without cellular phones. Results showed a significant increased rate among drivers with phones for inattention, unsafe speed, driving on the wrong side of the road, striking a fixed object, overturning, swerving, and running off the roadway. People with phones had an increased risk of being killed in an accident compared to those without phones. Male drivers with phones had significantly higher rates than females for many of these accident characteristics. Rate-ratios for some accident characteristics and fatalities increased with age, except drivers under 20 years who had the highest fatality rate.
Riu PJ, Foster KR, Blick DW, Adair ER, · 1997
Researchers measured human thresholds for skin warmth sensations at frequencies from 2.45 to 94 GHz. The thermal analysis suggests these thresholds correspond to a localized temperature increase of about 0.07°C at and near the skin surface. The thermal model results were insensitive to blood flow but sensitive to thermal conduction, with sensitivity increasing strongly with frequency. Thermal conduction becomes a dominant factor for surface temperature rise at microwave frequencies over 10 GHz.
Redelmeier DA, Tibshirani RJ · 1997
Researchers used a case-crossover design to study 699 drivers who had cellular telephones and were involved in motor vehicle collisions with substantial property damage but no personal injury. The risk of a collision during a call was four times higher than when not using a telephone, with a relative risk of 4.3. Calls placed within five minutes of the collision had a relative risk of 4.8, while hands-free units offered no safety advantage over hand-held units.
