Millimeter waves, also known as extremely high frequency (EHF) waves, typically have a wavelength ranging from 1 to 10 millimeters. In terms of human body penetration, millimeter waves do not penetrate deeply into the body. They are primarily absorbed by the outermost layers of the skin, specifically the epidermis and the top layers of the dermis.
This limited penetration depth is due to the nature of millimeter waves, which tend to be absorbed by water molecules within the body. As the human body is made up of predominantly water, millimeter waves are effectively attenuated and absorbed by this water content, preventing them from penetrating deeper into tissues or organs.
The shallow penetration depth of millimeter waves makes them useful in various applications, such as non-invasive medical treatments and wireless communication technologies like 5G. Their absorption by the upper layers of the skin allows for targeted treatments and high-bandwidth communication without significantly affecting the deeper tissues or organs.
Millimeter waves (mmWaves) can penetrate the human body to a certain depth, affecting most skin structures located in the epidermis and dermis[1]. The penetration depth of mmWaves in the human skin is typically around 0.65 mm at 42 GHz[1]. However, the penetration depth decreases rapidly with the increase of frequency[2]. More than 90% of the transmitted electromagnetic power is absorbed within the epidermis and dermis layers, and little power penetrates further into deeper tissues[2].
Some key points about mmWave penetration in the human body include:
– The penetration depth of 60-GHz radiations in the skin is typically 0.5 mm, resulting in specific absorption rate (SAR) levels that are significantly higher than those obtained at lower frequencies[5].
– The state of the art in the development of laboratory exposure set-ups at millimeter waves, as well as in the numerical and experimental millimeter-wave dosimetry, is provided in order to analyze the interactions between mmWaves and the human body[5].
– The skin can be considered as an anisotropic multilayer dispersive structure made of three different layers: epidermis, dermis, and subcutaneous fat layer[5].
– The interactions between mmWaves and the human body should be studied in detail due to the expected development of body-centric communication systems[5].
Alternative View
That’s the official answer. And some think it is a lie. Here is why in an excerpt from a book by Arthur Firstenberg at the cellphonetaskforce.org:
Deep penetration into the body
Another important fact about radiation from phased array antennas is this: it penetrates much deeper into the human body and the assumptions that the FCC’s exposure limits are based on do not apply. This was brought to everyone’s attention by Dr. Richard Albanese of Brooks Air Force Base in connection with PAVE PAWS and was reported on in Microwave News in 2002. When an ordinary electromagnetic field enters the body, it causes charges to move and currents to flow. But when extremely short electromagnetic pulses enter the body, something else happens: the moving charges themselves become little antennas that re-radiate the electromagnetic field and send it deeper into the body. These re-radiated waves are called Brillouin precursors. They become significant when either the power or the phase of the waves changes rapidly enough. 5G will probably satisfy both requirements. This means that the reassurance we are being given—that these millimeter waves are too short to penetrate far into the body—is not true. {Read More}
If you have been following the EMF safety debate, this is a highly significant point, because it allows 5G to trigger calcium floods into nerve cells causing them to fire and to die from apoptosis.
Another significant point is this concept of absorption, EMF getting absorbed, as if that is the end of the story. The first law of thermodynamics says energy is neither created nor destroyed, it can only be transformed.
Yes, that is correct. The first law of thermodynamics, also known as the law of conservation of energy, states that energy cannot be created or destroyed in an isolated system. It can only be transferred or transformed from one form to another. This principle is fundamental to our understanding of energy and its interactions in various systems and processes.
What happens when water in the body absorbs energy from millimeter waves? Where does that energy go?
When water in the body absorbs energy from millimeter waves, the energy is primarily converted into heat. This is due to the unique molecular structure of water, which allows it to absorb energy in the millimeter wave frequency range. As the water molecules vibrate and rotate due to the absorbed energy, the surrounding tissue heats up.
The energy transfer occurs at a molecular level, where the absorbed millimeter wave photons excite the water molecules, increasing their kinetic energy. This energy is then distributed through molecular collisions, transferring heat to adjacent molecules and tissues.
In terms of the biological effects, heating the tissue due to millimeter wave absorption can lead to thermal effects such as tissue warming. This can potentially be used in medical applications like hyperthermia therapy, where controlled heating of tissues can be beneficial in certain treatments. However, excessive heating or prolonged exposure to millimeter waves can also have adverse effects, leading to burns or tissue damage.
Yes, it is true that prolonged exposure to millimeter waves can have adverse effects, leading to burns or tissue damage. The intensity and duration of exposure to millimeter waves can affect the extent of tissue damage. More research is needed to fully understand the potential health effects of prolonged exposure to millimeter waves.
Remember, however, that officially, the energy levels used in typical millimeter wave technologies, such as Wi-Fi or 5G, are said to be generally not sufficient to cause significant heating effects or harm to human tissues. These technologies operate within safe limits set by regulatory bodies to ensure minimal risk of tissue damage.
Citations
[1] https://pubmed.ncbi.nlm.nih.gov/17929264/
[2] https://arxiv.org/pdf/1503.05944.pdf
[3] https://ieeexplore.ieee.org/document/1133316
[4] https://www.mdpi.com/1424-8220/20/5/1480
[5] https://www.cambridge.org/core/journals/international-journal-of-microwave-and-wireless-technologies/article/millimeterwave-interactions-with-the-human-body-state-of-knowledge-and-recent-advances/44B43B3E7CA335E5E1CD407BE2A1EA29
[6] https://ieeexplore.ieee.org/abstract/document/7740091
[7] https://www.degruyter.com/document/doi/10.1515/freq-2022-0100/html?lang=en
[8] https://www.tdcommons.org/cgi/viewcontent.cgi?article=3653&context=dpubs_series
[9] https://pubmed.ncbi.nlm.nih.gov/35408043/
[10] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9003280/