Novoselova ET, Fesenko EE. · 1998
Researchers studied whether weak electromagnetic waves in the centimeter range could affect tumor necrosis factor production in macrophages from mice. Whole-body microwave irradiation of male NMRI mice, exposure of macrophages in vitro, and irradiation of culture medium with 8.15-18 GHz at a power density of 1 microW/cm2 each caused a significant enhancement of tumor necrosis factor production in peritoneal macrophages.
Jauchem JR et al. · 1998
Researchers exposed 10 anesthetized Sprague-Dawley rats to ultra-wideband electromagnetic pulses at three different pulse repetition rates. Exposures at 50, 500, and 1000 pulses per second resulted in no significant changes in heart rate or mean arterial blood pressure during the two-minute exposures or in the two minutes after. The results suggest that acute whole-body exposure under these conditions does not have an immediate detrimental effect on these cardiovascular system variables.
Grigor'ev IuG, Stepanov VS · 1998
Researchers investigated how prior low-level electromagnetic field exposure affects memory formation (imprinting) in chicks. EMF at power densities from 0.4 to 10 mW/cm2 was found to potentially influence the forming of memory (imprinting). The study showed the possibility of EMF-modulated information being fixed in the embryonic brain during the natal period and conserved after birth.
Behari J, Kunjilwar KK, and Pyne S · 1998
Researchers studied the effect of low-level amplitude-modulated radiofrequency radiation on Na+–K+-ATPase activity in the brains of developing male Wistar rats aged 23 days. Rats were exposed to carrier wave frequencies of 147 MHz and its sub-harmonic frequencies 73.5 and 36.75 MHz, amplitude modulated at 16 and 76 Hz, for 30–35 days at 3 hours per day. Na+–K+-ATPase activity increased by around 19–20% in rats exposed with amplitude modulation at 16 Hz, and by around 15–16% in rats exposed with amplitude modulation at 76 Hz, compared to controls. The researchers concluded that the effect on Na+–K+-ATPase activity was insensitive to the carrier wave frequencies under investigation.
Adair ER, Kelleher SA, Mack GW, Morocco TS, · 1998
Thermoregulatory responses of heat production and heat loss were measured in seven adult volunteers (four women and three men, aged 21–57 years) during 45-minute dorsal exposures of the whole body to 450 MHz continuous wave RF fields. Two power densities were tested at each of three ambient temperatures (24, 28, and 31 °C), plus control conditions with no RF. No changes in metabolic heat production occurred, and deep body temperature was regulated to within 0.1 °C of the normal level through vigorous increases in sweating rate on the back and chest.
Kavaliers M, Choleris E, Prato FS, Ossenkopp K · 1998
Researchers studied how nitric oxide (NO) and nitric oxide synthase (NOS) influence opioid-induced antinociception in the land snail Cepaea nemoralis, and whether these chemicals play a role in the effects of extremely low frequency (ELF) magnetic field exposure. Pain relief was measured by how long snails took to withdraw their foot from a thermal stimulus of 40°C. Exposure to a 60-Hz magnetic field at 141 μT peak for 15 minutes reduced the enkephalinase-induced antinociception in the snails. The inhibitory effects of the magnetic field were significantly reduced by a nitric oxide synthase inhibitor and significantly enhanced by a nitric oxide releasing agent.
Phillips et al. · 1998
Researchers exposed Molt-4 T-lymphoblastoid cells in vitro to pulsed radiofrequency signals at cellular telephone frequencies of 813.5625 MHz (iDEN® signal) and 836.55 MHz (TDMA signal) to detect DNA damage. The alkaline comet assay was used to measure DNA single-strand breaks in exposed cell cultures compared to sham-exposed cultures. At an SAR of 24 μW g−1, exposure to the iDEN® signal for 2 h and 21 h significantly increased DNA damage, while at 2.4 μW g−1 the same signal significantly decreased DNA damage. The researchers concluded that the data indicate a need to study the effects of exposure to RF signals on direct DNA damage and on the rate at which DNA damage is repaired.
Unknown authors · 1997
Rats were exposed for 2 h to a 60 Hz magnetic field at flux densities of 0.1, 0.25, and 0.5 mT. DNA strand breaks in brain cells were assayed by microgel electrophoresis 4 h postexposure. Single-strand DNA breaks increased after exposure to 0.1, 0.25, and 0.5 mT, while double-strand DNA breaks increased at 0.25 and 0.5 mT.
Unknown authors · 1997
Unknown authors · 1997
Unknown authors · 1997
Unknown authors · 1997
Unknown authors · 1997
Hydrogels are popular for their high water content, softness, flexibility, and biocompatibility. They are made by cross-linking natural or synthetic hydrophilic polymers physically or chemically. Current uses include contact lenses, hygiene products, tissue engineering scaffolds, drug delivery systems, and wound dressings.
Unknown authors · 1997
Researchers studied intracellular calcium signaling in Jurkat E6-1 human T-leukemia cells during and after exposure to a 60 Hz magnetic field. Cells were labeled with Fluo-3, stimulated with anti-CD3 antibody, and analyzed by flow cytometry for calcium-dependent fluorescence.
Unknown authors · 1997
Researchers exposed ten patients with perceived electrical hypersensitivity and ten healthy controls to amplitude-modulated light. The sensitivity of the brain to this type of visual stimulation was tested using electroretinography and visual evoked potentials. Patients had higher cortical response amplitudes at all stimulation frequencies, but retinal responses did not differ.
Unknown authors · 1997
The authors conducted a literature study comparing skin changes in screen dermatitis with those from UV light or ionizing radiation. Screen dermatitis patients had a much higher number of mast cells. The most remarkable cellular change was the disappearance of Langerhans cells, which also occurs after UV or ionizing radiation.
Unknown authors · 1997
Researchers conducted a case-control study in northern Taiwan matching on date of birth, sex, and date of diagnosis to evaluate risks of adult leukemia, brain tumors, and female breast cancers in relation to residential exposure to 60-Hertz magnetic fields. The analysis included 870 leukemia cases, 577 brain tumor cases, and 1,980 female breast cancer cases. For leukemia, exposure to magnetic fields above 0.2 microtesla versus below 0.1 microtesla yielded an odds ratio of 1.4 (95% CI = 1.0-1.9), and living within 50 meters versus 100 meters or more from transmission lines gave a relative risk of 2.0 (95% CI = 1.4-2.9).
Unknown authors · 1997
Researchers conducted a nested case-control study of children aged 0 to 14 years who lived in census wards crossed by high-voltage power lines during selected years from 1960 to 1989. Exposure to electric and magnetic fields was calculated using computer programs that accounted for power line characteristics and distance. No association was found between time-weighted average magnetic field exposure and cancer at all sites, brain tumors, lymphoma, or leukemia. Cancer at other sites showed elevated odds ratios in the two highest exposure categories for some exposure measures, but the researchers noted that no firm conclusions could be drawn due to small numbers.
Unknown authors · 1997
The population-based case-control study conducted in northwestern Germany between 1992 and 1995 included 129 children with leukemia and 328 controls. Exposure was assessed by 24-hour magnetic field measurements in the child's bedroom at the residence where the child had lived longest before diagnosis. For exposure above 0.2 microtesla the odds ratio was 3.2 with a 95 percent confidence interval of 0.7 to 14.9, based on four leukemia cases and three controls. Exploratory analyses found no statistically significant increases for other magnetic field characteristics at varying cut-points.
Unknown authors · 1997
Researchers examined mortality trends among a cohort of 40,335 electric utility workers with at least one year of experience from 1960 to 1991, observing 3,753 deaths. They used standardized mortality ratios and internal cohort analyses to compare mortality across occupational groups. Standardized mortality ratios were generally at or below 1.0, indicating lower overall mortality, cardiovascular disease, cancer, and nonintentional injury rates than the general population. Internal comparisons showed higher respiratory cancer mortality for field staff, linecrew, and power plant workers relative to office staff, and higher injury mortality for nonmanagement occupations.
Unknown authors · 1997
Many epidemiologic studies suggest a relationship between leukemia incidence and exposure to 50/60 Hz magnetic fields. Radiofrequency currents used for communications have been detected on high- and medium-voltage lines. The intensity of RF fields is low but induced currents in the human body increase with frequency, so the authors argue RF fields must be considered in epidemiologic studies.
Unknown authors · 1997
Unknown authors · 1997
They note that EMF energies are far below those typical of biomolecules, induced electric forces are considerably smaller than biological forces, and magnetic-moment sensory cells have not been found in humans. Resonant interaction mechanisms conflict with accepted physics and many experimental tests have not found the predicted effects. The review states that biological effects at residential levels [< or = 2 microT (< or = 20 mG)] are implausible, while effects at higher fields [> 10 microT (> 100 mG)] might reach plausibility but lack demonstrated transduction structures.
Unknown authors · 1997
Researchers reviewed studies on leukaemia risk among people living near high voltage transmission lines of 49 kV and above. They calculated combined risks for distances of 50 meters and 25 meters and for magnetic field exposures at 2, 3, 4, and 10 milligauss. The combined analysis showed an odds ratio of 1.3 with a 95% confidence interval of 1.0 to 1.7 for exposures of 2 milligauss or higher. Odds ratios increased at higher exposures of 3, 4, and 10 milligauss, and risks were also elevated at distances of 50 and 25 meters from the lines.
Unknown authors · 1997
Researchers conducted a case-control study in Greece from 1993 to 1994 examining residential proximity to electrical power lines and childhood leukemia. The study included 117 incident cases of childhood leukemia and 202 matched controls. No statistically significant elevations of disease risk were found at higher exposure levels across four magnetic field exposure measures.
