The Effects of

Electromagnetic

Radiation

And The Truth to the

Controversy

Electromagnetic radiation (also known as EMR) is a common type of radiation that human beings are exposed to every day. Sources of electromagnetic ra-diation include radios, microwaves, televisions, and the Sun. Different types of EM radiation are categorized based on their frequency in a scale known as the electromagnetic spectrum.

A common misconception is that all EM radiation is harmful to your health. This is not true at all. In fact, the light that is shining on you right now is a form of electromagnetic radiation, known as visible light. Visible light has a fre-quency of approximately 400-790 THz (terahertz) and its own spectrum of col-ours, known as the visible spectrum.

There is a wide controversy regarding the radiation that devices such as cell phones and microwaves produce, and whether they are harmful to human be-ings or not. Various scientific studies have discovered arguments to both sides of this gruelling debate. The most important fact to note is that all electromagnetic radiation can be grouped into two categories: ionizing and non-ionizing. Ionizing radiation is considered dangerous; they can extract electrons from atoms or molecules, leading to serious health effects. Ionizing radiation is classified by the radioactive symbol seen to the right. Non-ionizing radia-tion also has health effects, but is much less severe than ionizing radiation. ?

Symbol: Frequency: High frequency (High-energy ultraviolet, X-rays, gamma rays) Health Effects: Radiation sickness (nausea, headache, fever,

etc.) Increased risk of cancer Radiation burns Infections Genetic mutations / DNA damage Can be lethal in moderate to high doses

Symbol: Frequency: Low to moderate frequency (Radio, microwave, infrared, visible light, low/moderate-energy ultra-violet) Health Effects: Increased body temperature Cataracts in eyes Headache / slight nausea (prolonged expo-

sure) Skin irritation (prolonged exposure) Burns to skin (extreme prolonged exposure) Non-lethal

The Technologies

Mobile Phone How It Works:

Inside every mobile phone is a transmit-

ter, which is the source of the electro-

magnetic radiation. The transmitter takes

the sound of your voice and encodes it in

a radio wave, which is broadcast out the

antenna of the phone. The waves are

broadcast to the nearest receiver in a cell

phone tower. These radio waves are a

form of electromagnetic radiation with

frequencies ranging from 105 Hz to 109

Hz, which are on the far left of the elec-

tromagnetic spectrum.

Type of EM Radiation:

Non-Ionizing

Analysis:

Contrary to popular belief, the type of

electromagnetic radiation that cell phones

produce is radio waves, which are low-

frequency and considered non-ionizing.

This means that they do not cause cancer

or radiation sickness. No link has been

established yet between mobile phones

and cancer. However, since mobile

phones are a rapidly advancing technol-

ogy, scientists agree that more research is

required before they can make a final

verdict on the health effects of cell

phones.

Microwave Oven How It Works:

As its name suggests, microwave ovens

use microwaves to heat food. The fre-

quency of these microwaves is approxi-

mately 2.5 gigahertz (2.5 x 109 Hz). A

device in the microwave oven known as a

magnetron produces the microwaves,

which are emitted into the central cavity.

These microwaves have a unique prop-

erty: they excite water, fat, and sugar

molecules to produce heat. The micro-

waves are not absorbed by glass or ce-

ramics. However, metal will reflect mi-

crowaves and possibly lead to electrical

discharge, potentially causing damage to

the magnetron.

Type of EM Radiation:

Non-Ionizing

Analysis:

Microwave ovens, like cell phones, pro-

duce non-ionizing radiation and are not

very harmful to the human body. Further-

more, the microwaves are contained in

the oven and the person is never directly

exposed to them unless the door is

opened while the oven is active, which

may result in microwave burns due to

thermal energy. Most microwave ovens

have a safety latch that does not allow the

door to be opened while it is running.

Power Lines How It Works:

The overhead power lines that you see

snaking through the sky, suspended on

thin metal structures, produce their own

electromagnetic radiation. Electric cur-

rent runs through these lines, producing a

magnetic field, and with it, EM radiation.

The radiation produced by these power

lines have an extremely low frequency:

about 60 Hz. As such, they lie on the far

left end of the electromagnetic spectrum.

Type of EM Radiation:

Non-Ionizing

Analysis:

Even if the radiation produced by power

lines is considered extremely low fre-

quency (ELF), it is still non-ionizing and

therefore is not very harmful. Most scien-

tific studies have not found any signifi-

cant link between electromagnetic fields

produced by these lines and health risks,

such as cancer. Still, scientists are not

completely sure if there is truly no risk at

all, but for now, they can say that long-

term health risks are low.

The Technologies

Television How It Works:

Most televisions use a device known as a

cathode ray tube (CRT) to produce the

colours that you see on a TV screen. A

CRT works by emitting electrons from a

electron gun to light up a fluorescent

screen, combining red, blue, and green to

produce the various colours. In the past, X

-rays, which are a form of ionizing radia-

tion, have been weakly detected from

CRTs and television screens. However, CRTs are now considered

a dead technology, replaced by LCD (liquid crystal display) and

plasma screens. These new televisions emit several different

kinds of electromagnetic radiation, most of which are categorized

as low frequency and non-ionizing. With the new technology,

almost none of the radiation can be categorized as ionizing. How-

ever, prolonged exposure to television screens is still not recom-

mended, as the non-ionizing radiation may cause eye damage

and/or cataracts.

Type of EM Radiation:

Non-Ionizing

Ionizing (weak, extremely low percentage in old CRT displays)

Analysis:

Televisions generally do not contain many health risks related to

electromagnetic radiation. In old CRT televisions, the amount of

ionizing radiation from X-rays was low. A person watching tele-

vision for a year would receive less than a tenth of the radiation

from a chest X-ray. There is still a debate as to whether new tele-

visions produce any dangerous radiation. However, since LCD

and plasma screen televisions are a rela-

tively new technology, scientists do not

have enough evidence to form arguments

for either side of the debate, and research

continues.

Computer How It Works:

Computers have become a daily part of our

lifestyle. They operate by means of a mother-

board, a CPU, and other hardware, along with

software programs such as an operating system

and anti-virus. Electric current runs through

computer hardware, generating an electromag-

netic field. This field generates electromagnetic

radiation, most of which is in the extremely

low frequency category. Like televisions, com-

puters also have different types of monitors. The two main types of

monitors are cathode ray tube and LCD monitors. As with televi-

sions, low-energy X-rays have been detected from old CRT moni-

tors. However, the majority of monitors today are LCD, and those

that still use CRT have been shielded from any form of ionizing ra-

diation. There has also been a debate about the health effects of

wireless broadcasting. However, scientific studies have shown that

these low-frequency radio waves do not have a significant effect on

the health of a human being.

Type of EM Radiation:

Non-Ionizing

Ionizing (weak, extremely low percentage in old CRT displays)

Analysis:

You may have noticed that staring at a computer

screen for too long may produce a slight headache.

This is the side effect of non-ionizing radiation, and

is not linked to an increased risk of cancer caused

by ionizing radiation. For this reason, it is still best

not to stare at a computer screen for a prolonged

period of time, as non-ionizing radiation still has its

effects on the human body with prolonged exposure. However, rest

assured that computers will not cause radiation sickness or anything

of the kind.