Saida Islam Sejuti
The effects of radiation on humans are noticed when the Uranium minors were found to suffer from cancer and skin burns. So at that time it was analyzed that how these radiations from these radioactive materials can be harmful. So the persons who are actually in touch with Uranium mining they suffer from cancer and skin burns after sometime. This cause an awareness among the scientists who actually know what is this radioactivity and radioactive pollution is.
The radioactive pollution can be referred as the physical pollution of living organisms and their environment as a result of release of radioactive substances into the environment during nuclear explosions and testing of nuclear weapons, nuclear weapon production and decommissioning, mining of radioactive ores, handling and disposal of radioactive waste, and accidents at nuclear power plants. The more we are getting civilized the more we are using radioactive materials for our greater conveniences. And this is how the radioactive pollution has become the worst side as well as the eventuality of our fast civilization.
The proportion of radioactive pollution is 15% of the total energy of any explosions. Radioactive pollution of water, water sources, and air space is the result of radioactive fallout from the cloud of a nuclear explosion. Radio nuclides are the main sources of pollution; they emit beta particles and gamma rays, radioactive substances. This radioactive emissions are not stoppable but the pollutions can be minimisable by proper disposal and by some treatment processes for all of anthropogenic well beings.
To understand the intensity of this pollution in environment, we need to know from very initial stage and that is from the radiation. The flow of energy in the form of electromagnetic waves, a stream of energetic charged particles (positively or negatively charged), from one space to another without getting in contact with the other surface is called Radiation. Radiation depends on frequency and wavelength. If the frequency is more and wavelength is small, then the energy will be more or higher. If the energy of radiation is high, then it will cause more harm to organisms.
Again Radioactivity is the phenomenon of spontaneous emission of protons (Alfa particles), electrons(Beta particles) & Gamma rays(shortwave electromagnetic waves) as a result of disintegration of atomic nuclei of some elements such as Uranium (Ur235, Ur238), Radium(Rd224), Thorium(Th232), Radon222 etc radioactive materials.
The rays produced in radioactive decay may cause ionization of atoms and molecules of the medium through which they are passing and convert them into ions. Alpha (α), beta (β), and gamma (γ) are majorly responsible for the radioactivity process, and those radiations are produced by the process called Radioactive Decay.
Alpha radiation contains charged alpha particles. Each alpha particle carries two units of positive charges and reacts strongly with living organism’s tissues. Beta radiation is made up of energetic electrons. Each beta particle carries one unit of negative charge and interacts strongly with matter. Gamma radiations are made up of high energy photons. Photons bring strong electromagnetic interaction with the matter. So in brief, the physical contamination of air, water and soil with radioactive materials is called Radioactive Pollution.
If we see the types of this hazardous environmental pollution we consider they as three—
1)Continuous- pollution constantly coming from Uranium mines, nuclear reactors, and test laboratories, where the radioactive contaminants are always present, 2)Accidental- pollution that occurs when certain experiments involving dangerous substances fail, and the substances used for experimentation get out of control, and 3)Occasional- pollution that occurs during nuclear tests or during experimental tests on radioactive substances.
Furthermore, the Radiations like a) Ionizing radiation and b) Non-ionizing are the core sources of this pollutions as they acts for radioactive decays. Moreover, Natural or background radiations and anthropogenic radioactive emissions are the major sources and causes of radioactive pollution.
The minor sources or causes are- Radioactive Minerals: In rocks, soil, and water, many radioactive elements, such as radium 224, uranium 235, uranium 238, thorium 232, radon 222, potassium 40, and carbon 14, are present. Also nuclear accidents from nuclear energy generation plants, spillage of radioactive chemicals, tests on radiation, inappropriate nuclear waste handling and disposal, coal ash etc.
The disastrous effects of radioactive pollutions can be seen as- 1) Short Range (Immediate) Effects; like- appear within days or a few weeks after exposure. The effects included loss of hair, nails, change in number and proportion of blood cells, subcutaneous bleeding, changed metabolism, and proportion of blood cells etc. & 2) Long Range (Delayed) Effects; like- appear several months or even years after the exposure. The effects are caused by development of genetic changes, mutations, shortening of life span, formation of tumors, cancers, etc. Moreover, all organisms are affected by radiation pollution. Some organisms preferentially accumulate specific radioactive materials. For example, oysters accumulate 65Zn, fish accumulate 55Fe, marine animals accumulate 90Sr.
The harmful effects of radiation were first observed in 1909 when it was found that uranium miners suffer from skin burn and cancer due to radiations from the radio-active minerals. Different organisms show different sensitivity to ionizing radiations. For example, tests have shown that pine trees are killed by radiations in which oak trees continue to thrive comfortably. It has again been reported that high altitude plants have developed polyploidy as a protective mechanism against radiations. The cells which actively grow and divide are quickly damaged. This category includes the cells of skin, intestinal lining, bone marrow, gonads and embryo.
As the preventions of radioactive pollutions are not in our hands, this pollution must need to minimized for our healthy survival. And the proper storage and disposal measures are only be helpful regarding this pollution specifically. Storing provide us with- a)Avoid any chance of radiation exposure to people, or any pollution, b)Radioactivity of the wastes decays with time, providing a strong incentive to store high-level waste for about 50 years before disposal, c)Disposal of low-level waste is straightforward and can be undertaken safely almost anywhere, d)Storage of used fuel is normally under water for at least five years and then often in dry storage, e)Deep geological disposal is widely agreed to be the best solution for final disposal of the most radioactive waste produced either.
Main focus of Radioactive Pollution related studies is how the hazardous wastes can be disposed with lesser destruction of mankind. And scientific researches have already discovered the way out to this extent fd appropriate disposal considering the categories of produced wastes.
1) Low-level Radioactive Waste (LLW) : LLW are typically sent to land-based disposal immediately following its packaging for long-term management. This means that for the majority (~90% by volume) of all of the waste types produced by nuclear technologies, a satisfactory disposal means has been developed and is being implemented around the world.
2)High-level Radioactive Waste (HLW) : a)the first step is storage to allow decay of radioactivity and heat, making handling much safer. b)Storage of used fuel may be in ponds or dry casks, either at reactor sites or centrally. c) Beyond storage, many options have been investigated which seek to provide publicly acceptable, safe, and environmentally sound solutions to the final management of radioactive waste. d)The most widely favored solution is deep geological disposal. The focus is on how and where to construct such facilities. Used fuel that is not intended for direct disposal may instead be reprocessed in order to recycle the Uranium and Plutonium it contains. e)Some separated liquid HLW arises during reprocessing; this is vitrified in glass and stored pending final disposal.
3)Intermediate-level Radioactive Waste (ILW) : disposed in a geological repository. In the USA, defense-related transuranic (TRU) waste – is disposed of in the Waste Isolation Pilot Plant (WIPP) deep geological repository in New Mexico. A number of countries dispose of ILW containing short-lived radioisotopes in near-surface disposal facilities, as used for LLW disposal too.
So as the consequences says that, Radioactive pollution is one of the most sensitive and harmful environmental concern and that is why it need to be treated with such strict supervision of radioactive expertise. Different radioactive emissions, cosmic rays and many other radiations are the main source of this pollution. Most of our anthropogenic causes and inappropriate disposal of radioactive wastes are leading the radioactive pollutions nowadays. Furthermore, the bigger concern is, these pollutions are not treatable or stoppable forever; we can just minimize the pollution level by sub-surface or deep sea burial only. The only way to get rid of this pollution is to be much conscious about the uses of radioactive substances and try to strictly follow all the certified rules while disposing radioactive pollutants in a larger view indeed.
Author; Student of Environmental Science and Engineering department at Jatiya Kabi Kazi Nazrul Islam University