BioElectroMagnetics

Human Safety and Biomedical Applications

Riadh Habash

• Publisher: CRC Press
• Year: 2020
• ISBN:
  9780429532641
• Edition: 2
• Topic: Medicina
• Subtopic: Biotecnologia in medicina

This book is an educational resource of evolving scientific knowledge in the area of bioelectromagnetics that may serve the interests of students and decision-makers, as well as society as a whole. It is distinguished by extensive descriptions of fundamental biophysical concepts and their relevance to human health. Reflecting the transdisciplinary approach from several different intellectual streams including physics, biology, epidemiology, medicine, environment, risk science, and engineering, the book is quite a venture into the battling studies to assess the latest research on health effects and biomedical applications of EM energy. This new edition of the book particularly looks at the potential threats from the emerging 5G wireless networks, which will deploy large numbers of low-powered smartphones, notebooks, tablets, radio access networks, and other transmitters.

Features

• Introduces necessary biophysical principles of EM fields in the context of their interaction with living systems.

• 
  
  

• Strengthens understanding of cutting-edge research on several major areas in the broad area of bioelectromagnetics.

• 
  
  

• Presents safety standards and guidelines for human exposure to EM fields.

• 
  
  

• Discusses techniques that have been developed to ensure adequate EM-thermal dosimetry required for both health effects and biomedical applications.

• 
  
  

• Provides insight into the determinants of EM health risk assessment and public concerns.

• 
  
  

• Includes extensive reference list at the end of each chapter to enhance further study.

• 
  
  

Riadh Habash is a special appointment professor and McLaughlin Research Chair in Electromagnetic Fields and Health at the University of Ottawa, Canada. He has been the recipient of many awards, including the National Wighton Fellowship Award, and has authored or co-authored over 90 research articles, six books, and five book chapters. His most recent books are Green Engineering in 2017 and Professional Practice in 2019 (CRC Press), with the remaining previous books targeting the area of bioelectromagnetics.

part one

Foundational Aspects of Bio + Electro + Magnetics

chapter 1

Foundations of electromagnetism

This chapter provides a brief background on the natural and artificial sources of electromagnetic (EM) fields. With the proliferation of artificial sources, health concerns have increased and the need for safety standards has as well. The foundations of EM fields, including theory and applications are discussed. Definitions of several fundamental concepts including electric and magnetic fields, electric charge, electric current, and EM field are extensively defined. Characteristics of EM waves, energy, propagation, and spectrum are presented. In addition, several dominant sources of electric and magnetic fields as well as radiofrequency radiation are outlined. The chapter concludes with a special section on 5G technologies to provide the reader with the basic characteristics of the emerging 5G wireless technologies.

The hypothesis

Humans evolved in the earth’s electromagnetic (EM) fields and in sunlight, both being essential to life. If there is too much sunlight, we burn, but what if the EM fields are at too high a level? What happens if background EM fields rise to critical levels, coinciding with increasing environmental pollutants [1]?

1.1 Natural and artificial electromagnetic fields

Life on Earth developed in an environment of natural EM fields. However, over the past century, this natural environment has changed with a fast-growing spectrum of artificial EM fields. Today, the earth environment consists of natural and artificial or man‐made EM fields.

1.1.1 Natural sources

One of main sources of natural EM fields is the sun’s radiation, where incident power density (PD) upon a human body ranges between 8 and 24 mW/cm² depending on season, atmospheric conditions, geographical location, etc. [2]. In addition, any object at a given temperature emits EM energy due to thermal radiation, including humans and mammals (for example, the human body emits EM energy at frequency of 31 THz). This is called black body radiation. In fact, the sun radiates energy only very approximately like a black body.

Other natural EM sources incorporate the earth’s electric and magnetic fields, including the magnetic field of the earth, electric fields caused by charges in the clouds, the static electricity of two objects rubbing against each other, or the electric and magnetic fields caused by thunderstorms and lightning, objects of cosmic origin, radio emissions from the sun and planets, relict radiation, and noise from atmospheric events like spherics and Schumann resonances. Spherics are broadband EM impulses that occur as a result of natural atmospheric lightning discharges; however, Schumann resonances are generated and excited by lightning discharges in the earth’s ionosphere. They originate from terrestrial and electrical discharges in the earth’s atmosphere and widespread spectrum radiation from sun and space.

1.1.2 Artificial sources

Artificial EM fields with various frequency bands have largely emerged in the last decades and almost everybody is exposed to rising levels. These fields are produced either intentionally or as by‐products. Today, the low frequency energy is used as a platform for electrification (power lines, substations, and transformers, electrical wiring in buildings, power tools, and appliances), while the higher frequency energy is used for wireless communication technologies (broadcasting stations, cellular systems, and other wireless networks), and various biomedical, sensing, and industrial applications.

The artificial EM fields are physical influences that permeate through all of space. They arise from electrically charged objects and describe one of the four fundamental forces of nature, “electromagnetism”, which is found almost everywhere, carrying energy and capable of producing an action at a distance. These fields have characteristics of both waves and particles and are utilized in various ways, though we still lack a full understanding of their fundamental properties. These EM fields under which devices and systems work extend from extremely low frequency (ELF) fields including very low frequency (VLF) fields (sometimes, VLFs are called “dirty electricity” since they are emitted, due to harmonic voltage and current distortions, from electrical wiring, lamps, and electronic devices) to radio frequency radiation (RFR), infrared radiation (IR), visible light, ultraviolet (UV), X-ray, and gamma ray frequencies exceeding 10²⁴ Hz. X-ray and gamma ray may come from natural sources, such as radon gas, radioactive elements in the earth, and cosmic rays that hit the earth from outer space. They can also be created in power plants for nuclear energy and are usually used for medical imaging and treatment, food irradiation, and security scanners.

The majority of ELF fields and RFR are artificial, however, the rest of frequency is mixed, natural and artificial. ELF fields include power frequency (50/60 Hz) fields associated with electricity supplies while RFR is associated mainly with 3 kHz–300 GHz frequencies which are extensively used in communications, navigation, industrial, and medical applications. Between power frequency and RFR, VLF fields in the kHz range exist. ELF fields and RFR are the commonest EM fields encountered in practice and are the main focus of this book.

Many EM inventions of the late twentieth century are so important and so advantageous, we wonder how we ever lived without them. These range from everyday home and office appliances to satellite and mobile systems, including emerging technologies such as cloud computing, machine learning, augmented and virtual reality, the Internet of Things (IoT), and billions of connected devices that are driving the frontiers of wireless networks like never before. The above technologies pledge faster and more reliable communications that will universally connect people. Table 1.1 shows a few typical examples of existing artificial EM sources.

Table 1.1 Examples of common artificial EM sources and corresponding fields

EM Source	Static	ELF/VLF	RFR
Various natural sources	x	x	x
Overhead power lines and underground cables		x
Substation and converter stations		x
Home appliances	x	x	x
High voltage direct current (DC) lines	x	x
Photovoltaic arrays for power generation	x	x
Wind turbines	x	x
Transformers and power substations	x	x
Wiring and equipment in homes and workplaces	x	x
Electric floor heating systems		x
Arc welders	x	x
RF sealers, induction heaters, and microwave ovens		x	x
Traction and rail systems	x	x	x
Aircraft power system	x	x	x
Broadcasting transmitters			x
Smart electricity meters		x	x
Cellular and mobile services		x	x
Wi-Fi and Bluetooth devices			x
Wireless sensor networks			x
Wireless Gigabit			x
Wireless chargers			x
Electric vehicles	x	x	x
RFID/EAS systems		x	x
Diathermy, hyperthermia, and ab...