Introduction: Man and all life forms on earth have evolved in a radiation environment. All non-living substances and generations of living beings are exposed to natural radiation. This is inevitable. The air we breathe, the water and beverages we drink, the food we eat are all parts of the same environment and contain radioactive materials, though in very small amounts. Thus atomic radiation is an inseparable part of our environment. It has been there from time immemorial.
Causes: Many are unaware of the existence of natural background radiation. The sources and causes of of these are extraterrestrial and terrestrial. The extraterrestrial natural radiation comes from outer space and hence these are called cosmic rays. The terrestrial natural radiation originates from the radioactive substances in the earth’s crust. These radiations irradiate the human body from outside: this exposure is known as External Exposure. ‘Internal Exposure’ arises from both these sources from naturally occurring nuclides which are taken up into the body through normal physiological pathways.
Effects of radiations: More is known today about effects of exposure to radiation than about any other physical and chemical agent in our environment. The health effects of radiation exposure are not unique. The Main effects of radiation are induction of cancer and genetic aberrations.
Impact of radioactive radiation: The effects of radiation may he (i) instantaneous (ii) prolonged or (iii) delayed. Even it can be carried to future generations or may result in production of defective embryos. All kinds of impacts depend on two major factors: doses of radiation exposure and duration of such exposures.
The effects of radiation are thus grouped, on the basis of effects on different cellular component levels, into the following:
- Radiation effect on DNA
- Radiation effect on chromosome
- Radiation effect on cellular level &
- Tissue response to radiation.
In addition, there are a number of gross physiological effects on the whole body including defects of circulatory, digestive and neurotic systems.
Tissue Response to Radiation: The radiation effects at tissue level are as follows:
1) Acute and chronic morphogenic effects on tissues.
2) Total body radiation syndrome viz. N-V-D syndrome (Nausea, Vomiting, Diarrhea).
3) Three general effects of radiation on the embryo & fetus: viz. lethality; congenital abnormalities present at birth and long-term effects on body after birth.
4) Late radiation effects i.e. induction of carcinogenesis.
Radiation protection: The radiation hazards were earlier not considered seriously as a major environmental threat for human health. However, the realization of deleterious effects of radiation hazards in recent years necessitates the need for protection against radiation hazards.
Global banning of nuclear weapons, safe disposal of nuclear plant wastes and proper dumping of radioactive materials used in therapeutic purpose etc. are the major activities undertaken currently as a measure of radiation hazard protection. In addition, the workers handling radioactive materials require undertaking appropriate protection measures while working at the nuclear plants premises. International Atomic Energy Commission has set up a standard guideline for the said purpose.
Frequently Asked Questions (FAQ)
1. What are Ions?
Ions are the molecules (or atoms) with positive or negative electric charge.
2. What is Ionization?
The process of forming ions is known as Ionization. During the process, a molecule (or atom) either gain electrons to acquire negative electric charge or lose electrons to acquire positive acquire positive charge.
3. What is Ionizing radiation?
The energy that is emitted to charge or ionize a atom (or molecule) is called Ionizing radiation. There are three types of ionizing radiation, viz. alpha, beta and gamma. Beta and Gamma are the very dangerous forms of radiation.
4. What is Radioactivity?
Radioactivity refers to the emission of ionizing radiation.
5. What are Radioactive substances?
Radioactive substances are substances or materials that emits ionizing radiation.