All around us
Cannot escape or control
It is a part of our planet
1. Background Radiation – it is natural radioactivity in the Earth and by cosmic rays
from outerspace. It can lead to mutation but does not usually cause harm to
2. Manmade radiation – cause by electronic products and is harmful to the human
These sources are controllable
Manmade Radiation is only 18% of all emitted radiations of which 4% is emitted from
nuclear medicines (used to cure cancer)
Natural Radiation is 82% of all emitted of which 55% is emitted by Radon.
Radiation can be divided into 2 groups based on the amount of energy possessed by the
1. Ionized – High energy (cosmic, gamma rays, etc); it has short wavelengths.
However, there is enough energy to break down chemical bonds and can harm
2. Non Ionized – Low energy (TV, microwaves, etc); it has long wavelengths. There
is not enough energy to rearrange chemical arrangement. The affects it has on
human health is still debated by scientists.
How does ionized radiation cause health effects?
Radioactive material that decay spontaneously producing ionizing radiation
o Strip away electrons from atoms
o Break some chemical bo