Aquatic Pollution and Coastal Management

Unit 10 : Radioactive pollution

10.3.Types of Radiation
Alpha Radiation
The unstable nucleus emits a particle consisting of two protons and two neutrons. Since the nucleons losses two positive charge, the atoms becomes that of an element two places lower in periodic table.
eg: Pu94239 ————> U92235 + α24 + γ
When plutonium 239 emits a α particle it is converted into uranium 235 having an atomic number of 143 and a mass number of 92
These are relatively slow moving and they cause damage to living tissue than particles with a longer path.

Beta Radiation
Beta radiation consists of electrons, these are released when a neutron is transformed into a protons by emitting a negatively charged particles i.e. electrons. These emissions will increase the atomic number by one with no change in mass number.
Eg: Xe54139 ————> Cs55139 + β + γ
Xenon 139 is converted into cesium 139 after emitting β particle.
Because of the lower mass, beta particle possesses a lower ionizing power than the alpha particles. When ingested source emits this radiation, it may become extremely dangerous.

Gamma Radiation
These are electrically neutral. These are produced due to the change in the energy level of nucleus in the atoms. They usually accompany the release of α or β particle. Because of shorter wavelength they have got a high capacity of ionization and are highly damaging to biological life.