1983 (2 od skupno 1333 raziskav)
"Microwave oven burns have been reported, but never properly documented. This paper attempts to document all aspects of radiation burn in a patient who stuck both hands and forearms into an active oven cavity for a few seconds to retrieve a food dish. She was exposed to the full output (600W) of the oven's magnetron tube. Questions about the safety of microwave ovens are raised because of the lack of free-standing radiation detectors as integral components of all ovens on the market."
"A parametric study of heat and pulsed microwave energy was performed on murine ocular lens in vitro. Adult rat lenses were placed in a specially designed chamber with thermostat in which temperature was maintained by the circulation of thermostatically regulated phosphate-buffered saline, during irradiation with 915 MHz microwaves. Irradiation in pulsed (Pu) mode was used. Lenses exposed at 37°C to pulsed irradiation at specific absorption rates (SAR) equal to or greater than 400 mW/g, and immediately fixed, showed numerous small holes (not previously reported for other in vitro cataracts) in the equatorial cell surfaces, when examined by scanning electron microscopy (SEM). At 39°C with SAR equal to or greater than 120 mW/g similar holes appeared. On continued incubation for two days the holes could not be seen as easily because globular degeneration appeared to advance into the equatorial areas where holes had originally been seen. In lenses exposed to 120 mW/g at 37°C globular degeneration and equatorial subcapsular foam were observed. At SAR values equal to or above 400 mW/g at 39°C and 1·2 W/g at 37°C, large globules characteristic of temperature elevation to 47 or 50°C were observed, indicating that the effect of the electromagnetic field itself in the absence of any comparable temperature elevation, was equivalent to a 10°C rise in temperature. An unexpected finding was the apparent fragmentational stretching of the capsule observed by SEM, in lenses fixed immediately after irradiation at 37°C at an SAR value of 1·2 W/g. These effects: holes, foam, large globules and capsular damage are apparent examples of physical damage to the lens. Modern radars using directional antennas can deliver pulse power densities many times higher than those employed in these experiments. This work indicates that additional effects of microwave irradiation dependent on modulation should also be considered as potential hazards in setting safety standards."