Page 156 - IGC BOOK

5.3 Radiation

What is Radiation?

Radiation is energy that is transmitted, emitted, or absorbed in the form of particles or
waves. The effect of radiation on our bodies is variable and the ability of this energy to ionise
body tissue is represented from the vast electromagnetic spectrum as “ionising” and “non-
ionising radiation”.

Types of Radiation and Health Effects:

Non-ionising Radiation

Has low energy that is not capable of ionising other atoms.
Ionising Radiation

The radiation has sufficient energy to ionise other atoms.

Non-Ionising Radiation – Types

Ultraviolet (UV) – emitted from sun, arc welding with high frequency electromagnetic radiation.

Visible light – can be seen by human eyes.

Infrared (IR) – low frequency radiation emitted from furnace, heat lamps.

Microwaves – emitted by microwave generator usually has a low frequency electromagnetic
radiation.

Radiowaves – emitted by antenna with low frequency electromagnetic radiation.

Health Effects

Health effects of non-ionising radiation is depending on the type of radiation exposed to.

Ultraviolet (UV) – Skin reddening and burns from exposure to sun; inflammation to the eyes
causing temporary blindness from welding arcs, excessive exposure may cause skin cancer.

Visible light - Excessive visible radiation can damage the eyes and skin.
IR – skin and eyes absorb infrared radiation as heat. Excessive exposure can cause cataracts and
pain.

Microwaves and Radiowaves - Microwave radiation (MW) is absorbed near the skin, while
Radiofrequency (RF) radiation may be absorbed throughout the body. At high enough intensities
both will damage tissue through heating.

Lasers - emit optical (UV, visible light, IR) radiations and are primarily an eye and skin hazard.
However human eye is more vulnerable to injury than skin.

ENSIGN | Unit IG2 – Element 5 – Physical and Psychological 16
Health