Hazards of Microwave Radiation

A Review from 1960.

Kuo-Chiew Quan. 1960. Hazards of Microwave Radiations – A Review. Industr. Med. Surg. 29:315-318, July 1960 and reprinted in Occupational Medicine, Medical News Letter, Vol. 36, No. 10. November 18, 1960, pp 29-34.

This document, written nearly 60 years ago, discusses the hazards associated with levels of RF Microwave Radiation exposure that might be experienced by those who work near radar installations, radio frequency heat sealers, or medical diathermy machines. Note: this article also applies to those who repair both broadcast and cell phone antennas.

Kuo-Chiew Quan makes several statements about energy absorption and thermal effects of microwave radiation.

Statement 1:

“any biological effects, beneficial or harmful, produced by microwaves can result only from absorption of energy by the tissues.”

Statement 2:

“all biologic effects of microwaves cannot be attributed solely to temperature increases that result from energy absorption or whether these effects are produced in part by mechanisms other than simple thermal elevation.”

Statement 3:

“at this time it is impossible to rule out the possibility of athermal effects of microwaves.”

The thermal vs athermal debate was well underway in 1960.

The concept that microwaves can kill had been known for decades. Rabbits exposed to a constant 300-watt field were killed after 75 seconds. The same power level killed a rat in 22 seconds and a hamster exposed to 400 watts died after a 20-second exposure. Death was attributed to thermal paralysis of the respiratory center. This makes microwaves considerably more lethal than x-rays.

  • Testis are damaged without any damage to the skin.
  • Cataracts occur optimally when exposed to 10 to 12 cm wavelengths (about 2.5 GHz frequency).
  • Cataracts are repeated reported by radar repair workers.
  • Lower power levels, at the same frequency, produce cataracts over a longer period of time so recurring exposures at lower intensities have the same effect as fewer exposures at higher intensities.

In 1957 a fatal exposure, attributed to microwave irradiation, was still debated 3 years later. To prevent injury it is important to point the radar beam away from people, to use metal screens to restrict the radiation beam, to use lights to indicate radar is operating, to indicate shape of radar beam with signage.

These practices should also be applied to all cell phone antennas that are placed on buildings or on any utility/light poles, on any “street furniture” in the public right-of-way, and cell towers near people since those in these areas are exposed to this RF Microwave Radiation 24/7/365 for many years, especially since cumulative, chronic RF Microwave Radiation exposures have similar effects to short-term acute exposures.