Unknown authors · 1994
A case-control study with 12 cases and 48 matched controls examined risk factors including distance to low frequency radio towers. The odds ratio for having lived within 2.6 miles of the radio towers before diagnosis was 2.0 with a 95% confidence interval of 0.06 to 8.3. The authors noted the clustering may have been a chance event but should be noted due to its peculiar characteristics.
Yee KC, Chou CK, Guy AW · 1994
Researchers investigated the effect of microwave exposure on conduction velocity of frog ventricular muscle. Thirty-two frog hearts were divided into four groups and placed in temperature-controlled waveguides with Ringer's solution. One group served as control while three groups were exposed for 2 hours to pulsed 2,450 MHz microwave fields at SARs of 0.003, 2, and 6 W/kg. No significant difference in conduction velocity was found between control and exposed groups.
Philippova TM, Novoselov VI, Alekseev SI · 1994
Researchers studied the effects of continuous wave and pulse-modulated 900 MHz microwave fields on rat chemoreceptors using in vitro assays. Binding of H3-glutamic acid to hippocampal cells was unchanged after 15 minutes of continuous wave exposure at 1 W/kg, while binding of H3-dihydroalprenolol to neonatal liver-cell membranes decreased fivefold under the same conditions. The decrease was due to shedding of receptor elements into solution and correlated with oxygen concentration in the suspension.
Nelson BK et al. · 1994
Researchers exposed rats to RF radiation that maintained colonic temperature at 42.0 degrees C for 0, 10, 20, or 30 min and to 2ME at doses of 0, 75, 100, 125, or 150 mg/kg on gestation days 9 or 13. Fetuses were examined on gestation day 20 for external, skeletal, and visceral malformations. Synergistic effects were observed for some treatment combinations but not others, with highly significant effects on gestation day 13 but little effect on day 9. Statistical analyses showed no global synergistic effect but evidence of synergism at intermediate dose levels.
Libertin CR et al. · 1994
Researchers used HeLa cells with a CAT reporter driven by the HIV LTR to test the effects of various radiations. Ultraviolet light increased HIV-LTR-driven transcription. Gamma rays, limited sunlight, and electromagnetic fields did not significantly affect transcription. Microwaves did not alter expression unless heating occurred, in which case transcription was induced.
Guberan E et al. · 1994
Researchers mailed a questionnaire to 2846 female Swiss physiotherapists and analyzed 1781 pregnancies. The gender ratio was 107 for 508 pregnancies exposed to shortwave radiation and 101 for 1273 unexposed pregnancies. There was no trend in gender ratio with increasing intensity or duration of exposure. Low birthweight prevalence was not related to exposure for either boys or girls. The findings of the Danish study could not be confirmed.
Bergqvist B et al. · 1994
Researchers studied the effect of 2.45 GHz microwave radiation on the permeability of unilamellar phosphatidylcholine liposomes. Leakage of 5(6)-carboxyfluorescein was measured using spectrofluorimetry after exposure to microwaves or thermal heating for 5-20 min intervals. The microwave exposure did not result in any non-thermal increase in permeability above that produced by thermal heating. The study refutes earlier results that reported increased liposome permeability due to microwave exposure.
Vergassola R et al. · 1994
Researchers studied the effects of various electromagnetic sources including short-wave diathermy, electrosurgical knives, electrotherapy, and radiofrequencies on both humans and animals. Short-wave diathermy was tested with various electrode positions in pigs and 8 patients with pacemakers. Electrosurgical knives were tested on pigs with unipolar knives, on 6 humans during automatic defibrillator implantation using two-pole knives, and on 23 pacemaker patients undergoing abdominal surgery using two-pole knives. Electrotherapy (TENS) and radiofrequency ablation were tested on pigs. The results were completely negative, leading the researchers to conclude that modern pacemakers are more reliable and less susceptible to electromagnetic interference.
Rosaspina S, Salvatorelli G, Anzanel D, Bovolenta R · 1994
Microwave exposure for 90 seconds provided effective, rapid sterilization of surgical scalpel blades contaminated with Candida albicans. Scanning electron microscopy showed that microwave irradiation induced a morphological modification of the cells. Longer exposure times caused greater alterations, with the microorganism fracturing after 9 minutes. Boiling water for the same duration killed the fungus but did not cause morphological alterations.
Lu Y, Yu J, Ren Y · 1994
Researchers measured dielectric properties of human red blood cells in suspension at 25 degrees C across 1-500 MHz using a coaxial transmission line reflection method. The study included 243 healthy persons with a hematocrit of 50%. The data revealed a statistically significant age dependence with a critical age of about 49 years, above which permittivity and conductivity decreased significantly.
Ikeda N, Hayashida O, Kameda H, Ito H, Matsuda T · 1994
Researchers investigated thermal damage to normal dog brain using 8 MHz radiofrequency interstitial hyperthermia. The heating limits were 42 degrees C for 45 min or 43 degrees C for 15 min. Breakdown of the BBB was observed at 43 degrees C for 60 min.
Zhao Z, Zhang S, Wang S, Yao Z, Zho H, Tao S, Tao L · 1994
The study aimed to investigate exposure limits for ultra-short wave radiation in work environments. Eighteen male rabbits were divided into four groups; three groups were irradiated with ultra-short waves at 100 MHz at power densities of 35, 1.5-3.5, and 0.07 mW/cm2 for 3 hours per day, 5 days per week for 24 weeks. Thermal effects occurred at 35 mW/cm2 and the thermal threshold limit value was set at 1.5 mW/cm2. An epidemiological survey of 136 factory workers and TV operators exposed to 0.2 mW/cm2 for over one year was compared with 108 controls. The exposure limit value for short wave radiation was set at 0.2 mW/cm2 using 15- and 20-fold safety factors.
Zhao Z, Zhang S, Zho H, Zhang S, Su J, Li L, · 1994
Researchers examined 121 workers exposed to radiofrequency radiation below 30 MHz for over one year, divided into high-intensity (>=100 V/m) and low-intensity (<100 V/m) groups compared to controls. No significant changes in autonomic nervous system functioning or blood parameters (hemoglobin, white blood cells, platelets) occurred in either exposed group. However, ECG changes including ST-T interval alterations and abnormal heart rate were observed in the high-intensity exposure group. The authors suggested 100 V/m as an exposure limit for radiofrequency radiation below 30 MHz.
Wu RY, Chiang H, Shao BJ, Li NG, Fu YD · 1994
The study used 115 Balb/c mice that were 4 weeks old, divided into control, DMH, DMH plus microwave, and DMH plus TPA groups. The microwave exposure was 2.45 GHz radiation at 10 mW/cm2 delivered dorsally in an anechoic chamber. Radiation was administered 3 hours daily, 6 days per week for 5 months, and DMH was injected once per week. Tumor incidence did not differ significantly among the three DMH treatment groups. Group D had more tumors, larger tumors, and more protuberant and infiltrative tumor types than groups B and C, and groups B and C did not differ.
Thuroczy G, Kubinyi G, Bodo M, Bakos J, Szabo LD, · 1994
At 30 mW/cm², total EEG power increased, while at 10 mW/cm² EEG did not change but cerebral blood flow increased. Brain-localized 4 GHz continuous-wave exposure at 42 mW/g SAR increased EEG delta power and REG amplitude simultaneously.
Somosy Z, Thuroczy G, Koteles GJ, Kovacs J · 1994
Researchers investigated the distribution and activity of Ca(2+)-ATPase in small intestine epithelial cells of mice after total body exposure to 2450 MHz microwave irradiation modulated at 16 Hz and X-ray irradiation. In control animals, enzyme activity was present in the brush border and lateral membranes, and lateral membrane activity was inhibited by quercetin. Microwave irradiation immediately decreased Ca(2+)-ATPase activity on lateral membranes, 1 Gy X-ray caused a similar reversible decrease within 24 hours, and 5 Gy X-ray reduced activity on both apical and lateral membranes persisting up to 24 hours.
Singh N, Rudra N, Bansal P, Mathur R, Behari J, Nayar U · 1994
Researchers exposed Twenty-three days old rats to 2.45 GHz microwaves at 1.0 mW/cm2 for sixty days and measured poly ADPR polymerase activity in various organs. The enzyme activity increased by 20% in liver and 35% in testis, while it decreased by 53% in brain diencephalon and 20% in cortex. No change was observed in spleen and kidney, and the changes were accompanied by alterations in NAD+ levels.
Sarkar S, Ali S, Behari J · 1994
Animals were exposed to microwave at a power density of 1 mW/cm2 for 2 h/day at a frequency of 2.45 GHz over a period of 120, 150 and 200 days. HinfI digested DNA samples from testis and brain of control and exposed animals were hybridized with a synthetic oligo probe (OAT 36) comprising nine repeats of 5'-GACA-3'. As compared to control animals, band patterns in exposed animals were found to be distinctly altered in the range of 7-8 kb which was also substantiated by densitometric analysis.
Salford LG, Brun A, Sturesson K, Eberhardt JL, Persson BRq · 1994
Researchers exposed male and female Fischer 344 rats to 915 MHz microwaves as continuous wave and pulse-modulated at 8, 16, 50, and 200 Hz in a transverse electromagnetic transmission line chamber. Albumin leakage occurred in 56 of 184 exposed rats versus 5 of 62 controls, and continuous wave exposure yielded 14 positive findings out of 35 that were significantly different from controls (P = 0.002). The specific energy absorption rate varied between 0.016 and 5 W/kg, and rats were exposed for 2 hours without anesthesia.
Quock RM, Klauenberg BJ, Hurt WD, Merritt JH · 1994
Researchers tested male mice in the staircase test after pretreatment with chlordiazepoxide at 8, 16, and 32 mg/kg and a 5-min exposure to microwave radiation at 4, 12, and 36 W/kg (1.8 or 4.7 GHz). In sham-irradiated mice, increasing CDP doses first increased steps ascended without affecting rears, then increased steps ascended and decreased rears, and finally decreased both measures. Microwave exposure did not alter steps ascended or rears at lower CDP doses, but at 32 mg/kg CDP, 36 W/kg microwave at 4.7 GHz significantly reversed the reductions in both measures.
Phelan AM, Neubauer CF, Timm R, Neirenberg J, Lange DG · 1994
Researchers exposed Sprague-Dawley rats to microwave radiation at 2.45 GHz and 80 mW/cm² for 30 minutes daily over four days, raising rectal temperature by 2.2°C. A separate group received radiant heat producing the same temperature rise. Microwave exposure reduced Mg(++)-ATPase activity by 48.5% and increased Na+/K(+)-ATPase activity by 170%, while radiant heat caused no significant changes in either enzyme. Microwave exposure also decreased the ratio of saturated to unsaturated fatty acids, whereas radiant heat increased it. Membrane fluidity measured by EPR differed among sham, microwave, and radiant heat groups, reflecting the fatty acid changes.
Mickley GA, Cobb BL, Mason PA, Farrell S · 1994
Researchers exposed rats to various doses of microwave radiation between training and testing to study effects on working memory. Memory was assessed by measuring relative exploration time of a familiar versus a new object, with extensive re-exploration of the familiar object indicating memory loss. Rats exposed to more than 5 W/kg developed hyperthermia, and microwave-exposed rats at doses of 1, 5, 8.5, 9.3, and 10 W/kg did not show a preference for the new object, unlike normothermic controls. Microwave hyperthermia evoked prominent c-fos expression in periventricular strata, hypothalamic nuclei, amygdala, and several cortical areas.
Lokhmatova SA, · 1994
Researchers studied the effect of long-term impulsive electromagnetic irradiation at a power density of 0.25 mW/cm2 for 4 months, 2 hours per day, on rat testes and epididymides. The irradiation was at 3 GHz and the results demonstrated high sensitivity of the rat testes and epididymides, with destructive changes in seminiferous tubules and testicular tissue. Full recovery was not observed even 4 months after irradiation ended.
Liddle CG, Putnam JP, Huey OP · 1994
Female CD1 mice were exposed from the thirty-fifth day of age for the remainder of their lives to 2.45 GHz CW microwave radiation at 3 or 10 mW/cm2. Exposures took place 1 h/day, 5 day/week in an anechoic chamber at an ambient temperature of 22 degrees C and a relative humidity of 50%. There were 25 animals in each exposure group, and an equal number of controls were concurrently sham exposed. The average life span of animals exposed at 10 mW/cm2 was significantly shorter than that of sham-exposed controls (572 days vs. 706 days; P = .049; truncation > 20%). In contrast, the average lifespan of the animals exposed at 3 mW/cm2 was slightly, but not significantly, longer (738 days) than that of controls (706 days).
Lai H, Carino MA, Horita A, Guy AW, · 1994
Researchers exposed rats to pulsed 2450-MHz microwaves for 45 minutes at a power density of 1 mW/cm2 with a whole body specific absorption rate of 0.6 W/kg. This exposure decreased cholinergic activity in the hippocampus as measured by sodium-dependent high-affinity choline uptake. Microinjection of beta-funaltrexamine (1 microgram) into the septum before exposure blocked the microwave-induced decrease.
