Wavelength of the ElectroMagnetic spectrum continually changes
high frequency = short wavelength
high frequency = high energy
high energy = more dangerous
Radio Waves (communications):
TV and FM radio (short wavelength)
Direct line of sight with transmitter (do not diffract)
Medium wavelength – travel further because they reflect from layers in the atmosphere
Satellite signals (Microwaves):
Frequency of microwaves pass easily through atmosphere and clouds
Cooking (Microwaves):
Microwaves are absorbed by water molecules.
These water molecules become heated > heat food
Dangers: microwaves are absorbed by living tissue Internal heating will damage or kill cells
Infrared Radiation (remote controls, toasters)
Any object that radiates heat radiates Infrared Radiation
Infrared Radiation is absorbed by all materials and causes heating
It is used for night vision and security cameras as Infrared Radiation is visible in daytime or night-time
Police use it to catch criminals, army use it to detect enemy
Dangers: damage to cells (burns)
Ultraviolet:
Dangers:
overexposure to UVA and B damaged surface cells and eyes and can cause cancer.
There is a problem with current sunscreens which protect against skin burning from high UVB but give inadequate protection against free radical damage caused by UVA.
Dark skins are not necessarily safer from harm.
Sun exposure for the skin is best restricted to before 11am and after 3pm in the UK in summer months.
Benefits:
sanitary and therapeutic properties have a marked effect on architecture, engineering and public health and have done so throughout history.
UVC is germicidal, destroying bacteria, viruses and moulds in the air, in water and on surfaces.
UV synthesises vitamin D in skin, controls the endocrine system and is a painkiller.
Used in state of the art air-handling units, personal air purifiers and swimming pool technology.
Used to detect forged bank notes: they fluoresce in UV light; real bank notes don’t. Used to identify items outside visible spectrum areas, known as ‘black lighting’.
X-rays:
X-rays detect bone breaks
X-rays pass through flesh but not dense material like bones
Dangers: X-rays damage cells and cause cancers. Radiographer precautions include wearing lead aprons and standing behind a lead screen to minimise exposure
Gamma Rays:
Gamma Rays cause and treat cancers
In high doses, gamma can kill normal cells and cause cancers
Gamma can be used to kill mutated cells though too.
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Heⅼlo just wanted to give you a brief heads up and
let you know a few of the images aren’t loading properly.
Ӏ’m not sure why but I think its a linking iѕsue. I’ve tried
it in two different web browsers and bοth show the same results.