Radiation is energy released in the form of particles and or electromagnetic waves. Particles are small localized objects having physical properties such as colour, density and volume, and chemical properties such as conductivity and oxidation. Particles vary in size. Particles associated with radiation are very small at times, invisible to the eyes. They have their own energy. Electromagnetic waves on their own are waves generated as a result of vibrations or interactions between electric and magnetic fields. They can be said to be oscillating magnetic and electrical fields.
The common sources of radiations are cosmic rays, which are the highly energetic particles from the sun and stars. Some of these particles get to the ground, interact with other materials in the soil. Medical X-rays, which are the particles with energy, released by unstable chemical elements. Example of these chemical elements is tungsten. Radioactive materials have been reported to be existing naturally in the body of plants and animals. Potassium – 40 is found in the food, soil and water. Thorium and uranium are found naturally in the earth. They have been reported to be the main source of terrestrial radiation. These elements released alpha radiation. Man-made sources of radiation exist. Nuclear reactors release radioactive elements. Some industrial activities such as mining and electricity generation release radiation.
Radiation can be detected using Geiger – Mueller counter, Scintillation counter, Diffusion cloud chamber and Silicon solid state detectors. Radiations are of four major types. They are alpha, betta, neutron and electromagnetic waves/radiations such as microwaves, radio waves, infra-red, visible light, x-rays and gamma rays.
Researchers reported variation in the spatial distributions and concentrations of radiations in soils. Commonly encountered radioactive isotopes found at dumping sites are uranium – 238, thorium – 232, potassium – 40, cesium – 137 and radium – 226. Radium produces radon (a gas) when it disintegrates. When radium is ingested, about 80% of it leaves the body through feces. Defecating at the dumping site leaves the element there. Radiation from radium produces alpha and gamma rays, which can destroy body tissues and cells.
Cesium emits alpha and gamma rays. Its deposition in the body destroys tissues. It gets to dumping sites through natural means, erosion and food decay deposits. Potassium – 40 is the largest source of natural radioactivity in animals and man. It is present in banana. Dumping of banana, potatoes, sun flower seeds, tobacco introduces potassium – 40 into the soil. It’s too much exposure causes damage of the cell and exposes the body to cancer. Does it means eating banana is dangerous? NO. Disintegration must occur before radiation are released. This is not possible in human body because disintegration takes very long time to occur and the body cannot store excess banana, they are excreted. Uranium gets to food through leaching from natural sources such as soil, rock, water and air. Wastes from poultry, in beef, eggs, root vegetables may contain uranium. Dumping these wastes may increase the deposit of this radioactive element at the dumping sites. Human kidneys can be destroyed through ingesting large amount of uranium.