Electromagnetic Energy (EME) is an energy phenomenon which propagates in the form of a wave. The EME wave is made up of two major components, the Electric Field and Magnetic Field. Both these fields propagate both perpendicular to one another and perpendicular to the direction of its motion.
EME is a natural abundant source of energy within our world and is often around us without even being conscious of its presence. EME energy can be present in various forms, some are visible to the naked eye, some can only be heard and others are indefinitely discrete to us without the use of special devices to detect its presence. The key factor which allows each type of EME to be distinct and unique to one another yet still propagate in the form of energy is its wavelength-frequency relationship. This means different forms of EME only vary to one another according to their frequency of propagation.
With this inevitable presence of EME within our world, most originating naturally yet others engineered to be used for a specific purpose (i.e. mobile communications), it has been a natural curiosity to human beings to understand this phenomena and its fundamental nature, yet more importantly people are interested in understanding what danger implications are associated with such a strong presence of EME within our daily lives.
Shown below are all the types of EME sources we can potentially be exposed to within our daily lives. Note the very limited EME fields we can physically see (i.e. ‘visible’ EME) from the large range of EME fields which lies between the range of (380 – 780)nm. Second fact to note is the very large part of the spectrum which although actually exists, we are not conscious of its presence. Hence, with this understanding in the existence of various types of EME, it is only natural for human beings to question what sort of impact all these EME fields have on the health and the safety of our selves and of our environment.
Figure 1.
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EME fields are often distinguished by one of two categories ‘Ionizing’ or ‘Non-Ionizing’ EME Fields. Considering all EME fields are distinguished by their frequency-magnitude or frequency-wavelength relationship, therefore each EME field type naturally propagates with a different magnitude of energy in relation to others. EME fields at the higher end of the frequency spectrum carry much more energy during propagation compared to frequencies in the lower end. These fields which contain a high abundance of energy are referred to as Ionizing Fields.
Ionizing fields are any EME fields which propagate at very high frequencies and as a result can carry enough energy during propagation to break down bonds between molecules. Referring to Figure 1 above, only three major types if Ionising EME fields exist and are categorized ‘Gamma Ray’, ‘X-Ray’ and ‘Ultraviolet Rays’.
Non-Ionizing fields are EME fields which propagate with much less energy. EME field type which do not have the ability to break down bonds between molecules are called Non-Ionizing fields. Commonly, ‘man made’ enhanced engineered EME sources are classified as Non Ionizing. These include and are not limited to ‘Radio Waves’, Microwave Rays’ and majority of ‘Infrared Rays’. Although many of the technologies human-beings often use within their daily lives (namely Mobile Phones) are classified as ‘Non-ionizing’ EME fields, this does not guarantee the EME fields we are exposed to are entirely safe. All fields can potentially be dangerous and may contribute to prolonged health effects, however, as a ‘rule-of-thumb’, all EME signal waves classed as non-ionizing are theoretically safer than signals at the higher end of the spectrum.
Electromagnetic Energy (EME) is a wave which propagates at the same speed of light. An EME wave is made up of two fundamental fields which are the ‘electric field’ and the ‘magnetic field’. Both these fields travel perpendicular to each other and perpendicular to the direction of motion.
An electric field is created when a potential difference exists within a medium. A magnetic field exists when a flow of electrons (i.e. current) passes through a medium. Hence an electromagnetic field is created when the presence of both an electric field and a magnetic field exist together. Both electric and magnetic field are solely dependent on one another as they vary over time. Hence, when an electric field varies over any given period of time, a magnetic field is created and the opposite occurs when a magnetic field varies over time.
All types of EME within existence in our world are represented as a ‘transverse’ wave and each type is unique due to its frequency-wavelength magnitude relationship. Shown below is a typical EME wave expressed by its frequency-wavelength relationship.
Figure 2.
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Frequency: Frequency is defined as the amount of cycles a wave completes within a set time interval (i.e. over a 1 second interval).
Wavelength: Defined as the distance between two peaks or troughs of an electromagnetic wave.
With a continuous growing number of mobile users and the inevitable network expansion to handle the growing traffic, as a result of these growths, EME cumulative exposure naturally increases too. Hence, the Australian government along with international governed agencies, have joint forces to set international standards and regulations to ensure the general community are aware of all the potential health affects they are exposed too, how to handle and control the EME levels and to ensure all Australian and International operators are aware of all the international standards and regulations and more importantly enforce these protocols to ensure the awareness and safety of the environment and the greater community.
Some nationally and internationally recognised organisations and institutions very active within the field of ‘community awareness of EME exposure’ are as follows.
ACMA
The Australian Communications and Media Authority or better known as ACMA is an Australian organization regulated by the Australian Federal Government to set cohesive standards and regulations on Australia’s Broadband, Communications and Digital Economy.
ACMA plays a vital role to Australia’s media standards and regulations and are responsible for regulation within the following categories.
* broadcasting
* the internet
* radio communications
* telecommunications
Currently, ACMA has close relations and works first hand with relevant industries to achieve active self-regulation, yet still ensuring industry compliance and license conditions are achieved. ACMA are also responsible for regulating Australian codes and standards and continuously monitor the effect of regulation to ensure all community needs are satisfied.
Due to ACMAs vital responsibility, hence ACMA ensure all the necessary precautions are taken when regulating EME standards and regulations to ensure the EME levels exposed to the wider community from communications towers are not harmful and are in fact many levels less than those found to cause significant health effects.
http://www.acma.gov.au/
ARPANSA
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is the Australian Government’s primary authority on radiation protection and nuclear safety. ARPANSA regulates Commonwealth entities using radiation with the objective of protecting people and the environment from the harmful effect of radiation. ARPANSA undertakes research, provides services, and promotes national uniformity and the implementation of international best practice across all jurisdictions.
http://www.arpansa.gov.au/
WHO – World Health Organization
The presence of the World Health Organization (WHO) enables groups such as ACMA and ARPANSA to set and regulate standards and regulations to ensure the safety of the public throughout the world. WHO is an established authority organization set up and routinely run by the United Nations. WHO has many responsibilities which include the following.
◦ providing leadership on global health matters
◦ shaping the health research agenda
◦ setting norms and standards
◦ articulating evidence-based policy options
◦ providing technical support to countries
◦ monitoring and assessing health trends
Apart from WHOs responsibilities as mentioned above, WHO along with other international organizations have worked together and contributed ideas and research results in order to formulate and establish guidelines for occupational health and safety from EME exposure limits.
http://www.who.int/en/
ICNIRP – International Council on Non-Ionising Radiation Propagation
The International Council on Non-Ionising Radiation Propagation or better known as ICNIRP is an international government funded organisation made up of a team of independent scientific experts. The prime commission organisation is made up of 14 members with 4 Scientific Standing Committees which cover research in areas ranging from Epidemiology, Biology, Dosimetry and particularly Radiation (Non-Ionising and ionising).
ICNIRP is standardised measuring unit commonly practiced within many European Countries and others around the world and basically sets a standard (i.e. acceptable EME exposure limits) to RF exposure limits. ICNIRP is a common standard which can be categorised into two types of exposure limits. The first which is also referred to as the higher limit refers to Occupational limits while the second, which is referred to as the ‘restrictive level’ refers to the General Population. Both these limits according to its electric and magnetic field components are very similar to the limits set out by the 1997 FCC.
http://www.icnirp.org/