RF Biohazard Information


Cell phones and cellular base stations have been popular in the press in relation to fears of health risks. In the Radio Frequency industry, this is known as "RF Biohazard". As cell phones and cellular base stations were the major subject of study in my Wireless Communications graduate class at SUNY New Paltz, for the class project I decided to investigate RF Biohazard to be able to understand for myself and others whether cell phones and cellular base stations are safe or not.

As a result of years of RF industry experience as well as this continued investigation, I am of the opinion that both cell phones and cellular base stations are safe. And with further information below, I will try to explain why as simply as possible.

And if you want good free online references that explain RF Biohazard, I suggest reading:

Ionizing vs Non-ionizing radiation

Ionizing Raditation means emissions of high energy, which are capable of penetrating matter, which can cause ionization of the atoms, and break chemical bonds and cause harm in living matter. These emissions can cause cancer by causing errors in DNA.

Non-Ionizing Raditation means emissions of lower energy, not capable of ionization, but are capable of affecting the cells electrically, chemically and/or thermally.

As you can see from the Figure 1 below, Radio Frequency transmissions (also known as Electromagnetic Radiation) are in the Non-Ionizing portion of the spectrum.

Electromagnetic Spectrum
[Figure 1: Electromagnetic Spectrum. Image from the Greek Atomic Energy Commission]

Note the Energy in Electron Volts (eV) in Figure 1 above -- the amount of energy in a transmission emission or transmission is directly proportional to the frequency of the intividual photons. [If you have trouble accepting that photons are frequency universal, conceptually consider these "photons" to be "the individual pieces that make up a transmission or emission".] This was discovered by Max Planck in 1900, who quantified it as the Planck Constant:

Energy = H * frequency(in Hz)       where H = 4.135667x10-15 eV*s    (eV*s = electron volt seconds)

Cancer is caused by errors in the cellular DNA such that the cells with genetic faults replicate without the DNA errors being detected and destroyed by the immune system. Approximately 90-95% of cases of cancer are due to environmental factors rather than genetics, but only up to 10% are due to any kind of radiation, ionizing or otherwise. In my less-than-humble opinion as an RF Engineer, because Microwave transmissions are all entirely in the Non-Ionizing region they do not have sufficient energy to cause cancer. The first type of energy emission that has the required ionization energy is far Ultraviolet Light, somewhere in the neighborhood of 100 eV at a frequency of approximately 24 petahertz. For those more familiar with frequency in units of giga, that's 24,000,000 gigahertz. This is a frequency well outside of the norm for a microwave engineer to be working with, which is more commonly in a range of 1 to 60 gigahertz. Occasionally there is some more exhotic work at higher frequencies, but the parts become tremendously easy to damage. For instance, I briefly did some work at 180 GHz for a commercial weather satellite relating to a set of mixing diodes on a die, but the part was so ESD sensitive that dropping the part would destroy it while it was falling due to the static buildup from the air moving past it. And it took months to procure another one, because the manufacturer had an incredibly low success rate in manufacturing them for the same reason.

Now compare the frequency ranges that cell phones use, and their respective energy levels:

celular servicemaximum frequencymaximum energy level
CDMA1870 MHz7.734x10-6
GSM1989.8 MHz8.229x10-6
LTE2600 MHz10.75x10-6
UMTS2690 MHz11.12x10-6
WiMax~3500 MHz~14.47x10-6
E-ULTRA3800 MHz15.72x10-6
spectrumminimum frequencyminimum energy level
FCC ionizing radiation2,418,000,000 MHz1.000x101
ionizing radiation~24,000,000,000 MHz~1.000x102

The energy level of transmissions for mobile phone use and ionizing radiation aren't even in the ballpark of one another. If you take the highest energy level of mobile phone transmissions and the lowest  "FCC definition" energy level of ionizing radiation and directly compare them:

1.000x101 eV / 15.72x10-6 eV = 636,000 times lower energy level

That's why I think microwaves can't cause cancer.

Effects of Microwave energy exposure

Microwave transmissions have been studied for over 60 years. Thusfar, the only known effect that I know to be a fact is Microwave Heating. Occasionally one can find statistical studies that show correlation between microwave energy exposure and non-heat related biological effects, however it is important to understand that statistical correlation does not prove causation. In other words, just because a "possible link" via correlation is found does not prove that the root cause for the correlation has been found.

Microwave Heating

Powerful transmissions of low-energy photons

Right about now you might be thinking that perhaps a massive amount of microwave energy could produce cancer, and that perhaps the energy level of the individual photons of the transmission aren't relevant.