Electromagnetic Waves When scientists talk about waves, they could be referring

Question

Electromagnetic Waves

When scientists talk about waves, they could be referring to the kind that move across the surface of water, the kind that move across the surface of land in the form of earthquakes, or even those that carry energy through space without the need for a medium like water or the crust of the earth.

Your cousin Pauline, once a proud microwave chef, has taken to dining out a lot more often and using her toaster oven for the leftovers. She recently learned of the dangers of radiation, thanks to rising awareness of the dangers of tanning booths and even recent disasters at nuclear power plants, and is concerned that her microwave could pose a threat to her own health. What should Pauline know about these different forms of radiation? Which forms are dangerous and why? Can you convince her to return to her microwaving ways?

In an attempt to show Pauline there are even more forms of electromagnetic radiation which are not only harmless but actually helpful, you ask if she has ever experienced infrared light treatments at the chiropractor, or if she is aware of the medical uses for infra-red imagery. Although it might scare her, you show her the following image infrared photograph of a group of people. Explain to her what she is “seeing” in these images, and how infrared radiation differs from that used for X-ray imaging.

What are some of the controversies concerning the dangers of extremely low-frequency (ELF) radiation? Based upon the Reading and your own experience, do you think this is a topic you should discuss with your cousin Pauline?

Write and submit a short paper responding to the questions provided listed for the live Seminar. Your paper should contain a minimum of 400 words and should follow APA format for all citations and references.

Explanation / Answer

1. Types and Sources of Radiation

Radiation is energy in the form of waves of particles. There are two forms of radiation – non-ionizing and ionizing.

1.1 Non-ionizing radiation

Non-ionizing radiation has less energy than ionizing radiation; it does not possess enough energy to produce ions. Examples of non-ionizing radiation are visible light, infrared, radio waves, microwaves, and sunlight.

Global positioning systems, cellular telephones, television stations, FM and AM radio, baby monitors, cordless phones, garage-door openers, and ham radios use non-ionizing radiation. Other forms include the earth’s magnetic field, as well as magnetic field exposure from proximity to transmission lines, household wiring and electric appliances. These are defined as extremely low-frequency (ELF) waves and are not considered to pose a health risk.

1.2 Ionizing radiation

Ionizing radiation is capable of knocking electrons out of their orbits around atoms, upsetting the electron/proton balance and giving the atom a positive charge. Electrically charged molecules and atoms are called ions. Ionizing radiation includes the radiation that comes from both natural and man-made radioactive materials.

There are several types of ionizing radiation:

Alpha radiation (): is a positively charged helium nucleus emitted by a larger unstable nucleus. It is a relatively massive particle, but it only has a short range in air (1–2 cm) and can be absorbed completely by paper or skin. Alpha radiation can, however, be hazardous if it enters the body by inhalation or ingestion, because large exposures can result in nearby tissues, such as the lining of the lung or stomach.

Beta radiation (): is an electron emitted by an unstable nucleus. Beta particles are much smaller than alpha particles and can penetrate further into materials or tissue. Beta radiation can be absorbed completely by sheets of plastic, glass, or metal. It does not normally penetrate beyond the top layer of skin. However large exposures to high-energy beta emitters can cause skin burns. Such emitters can also be hazardous if inhaled or ingested.

Gamma radiation () is a very high energy photon (a form of electromagnetic radiation like light) emitted from an unstable nucleus that is often emitting a beta particle at the same time. Gamma radiation causes ionization in atoms when it passes through matter, primarily due to interactions with electrons. It can be very penetrating and only a substantial thickness of dense materials such steel or lead can provide good shielding. Gamma radiation can therefore deliver significant doses to internal organs without inhalation or ingestion.

X rays are high-energy photons, like gamma radiation, and are produced artificially by the rapid slowing down of an electron beam. X rays are similarly penetrating and, in the absence of shielding by dense materials, can deliver significant doses to internal organs.

2. Health Effects of Radiation Exposure

The word “safe” means different things to different people. For many, the idea of being safe is the absence of risk or harm. However, the reality is that almost everything we do presents a certain level of risk

For example, speed limits on roads are set to maximize safety. Nevertheless, accidents occur even when drivers obey the speed limit. Despite this risk, we still drive. Similar informed decisions are made when radiation is used. Radiation exposure carries a health risk. Understanding the risks helps the regulatory bodies to establish dose limits and regulations that keep exposure at an acceptable or tolerable risk level, where it is unlikely to cause harm.

One significant advantage of radiation is that more is known about its associated health risks than about any other chemical or otherwise toxic agent. Since the early 20th century, radiation effects have been studied in depth, in both the laboratory and among human populations.

3. ELF field sources and its effects

Short-term effects

There are established biological effects from acute exposure at high levels (well above 100 µT) that are explained by recognized biophysical mechanisms. External ELF magnetic fields induce electric fields and currents in the body which, at very high field strengths, cause nerve and muscle stimulation and changes in nerve cell excitability in the central nervous system.

Potential long-term effects

Much of the scientific research examining long-term risks from ELF magnetic field exposure has focused on childhood leukaemia. In 2002, IARC published a monograph classifying ELF magnetic fields as "possibly carcinogenic to humans".

This topic need to be discussed with Paul Cousin Pauline for counselling about different radiation types and its health effects.

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