From nuclear energy the most dangerous is the fact that running a nuclear reactor essentially releases radioactive material into the environment. Radiation is a energy travelling in the form of electro-magnetic waves or photons. It is also a stream of particles, especially alpha or beta-particles from a radioactive source or neutrons from a nuclear reactor. Radiation damages generally living organism as a result of exposure to energetic electrons, nucleons, fission, fragments, or high-energy electro- magnetic radiation. In organism, these mechanisms can cause changes to cells that alter their genetic structure, interfere with their division or kill them. In human, these changes can lead to radiation sickness, radiation burns or to long-term damage of several kinds, the most serious of which result in various forms of cancer. This fact was proved in a study conducted by US government to assess the late effects of radiation among the atom survivors of Hiroshima and Nagasaki. These are the only two occasions when nuclear force was intentionally developed and deployed to kill human life.
Large biological effects
In our daily life activities, we are exposed to ionising radiation both from natural and human-made sources. The passage of ionising radiation through the body may produce adverse biological effects. The effects of concern are primarily although not solely, due to damage to the genetic material inside the cell; the DNA or double helix’ molecule that carries genetic information. At present there is no safe minimum, or threshold, for adverse radiation effects on the DNA of biological systems and that even small doses can produce consequences for the organism. The biological systems are composed of many individual tiny cells; each with its own DNA. If there is catastrophic damage to vital cell function by radiation energy absorption, the cell may cease to function and die.
Among the damages done to cells and DNA the most common and fierce is cancer induction. In this case, the DNA is damaged or altered but the alteration is not lethal to the cell. If the normal regulator genes which control the rate at which cells divide and die are rendered malfunctioned the cells may become immortal and multiply at an abnormal rate producing an out of control growth of a line of abnormal cells. This is a cancer. Most tissues can produce cancers with enough radiation damage but rapidly dividing tissue lines, such as blood forming haemopoietic gene which may produce lukemias, are particularly vulnerable. The risk for cancer production in the general population is estimated to be approximately 0.06 cases per million Micro-Sieverts of absorbed dose.
Besides, it is also responsible for genetic damage to future generations. This can arise because mutations or changes in the pattern of bases in the DNA, can occur in the DNA that ends up in sperm or eggs and becomes a permanent feature of any resulting babies. Most often, radiation induced damage to such egg or sperm DNA is incompatible with the life of the foetus in utero but there is a finite chance of a live baby being born with defects. This is of particular concern because the damage to the genetic material can then be passed on to all future generations and become a permanent features of the gene- pool; damaging many individuals. Of course such mutations are also a natural part of life and the evolution of biological systems.
The theoretical description of nuclear power plant on human body does not appear much devastating as it is in practice right from the days of dropping the atomic bomb on Hiroshima and Nagasaki, Japan, in 1945 the humanity has faced the disaster. After this the Chernobyl nuclear plant accident of 1986, proved most fatal for human health and its after-effects are studied even today. The death toll from the Chernobyl explosion remained a hotly-debated issue between the International Atomic Energy Agency and the various writers, researchers. Green-peace has predicted that Chernobyl may ultimately cause some, 2,70,000 cancer cases, more than 90,000 of which could prove fatal. In a book published in 2007, Russian biologist Alexei Yablokov and two Ukrainian researchers concluded that some 9,85,000 people had already died, mainly of cancer, till 2004. In between the two is the official view of the UN watchdog which expected that death toll among those affected by high radiation doses at Chernobyl may reach 4,000 in the coming decades. But according to the official data from Ukraine’s Health Ministry: 530,000 died from radiation in the former Soviet state between 1987 and 2004.
Other fatal effects
Apart from health hazards caused due to accident in a nuclear plants, because of radiation and other related factors are also responsible for slow death of plant workers and bad health in surroundings. Under normal peacetime conditions, workers who handle X-ray machines or radioactive isotopes are exposed to very small doses of radiation.
Afterwards, sometimes years afterwards, many of them are afflicted the most painful forms of dermatitis and cancer, and a large number died from the effects of the rays. Similar affects have been observed in individuals , who have ingested substantial amount of radioactive substances. Not all of these are equally dangerous, and the body can tolerate quite a large amount of some which are exerted rapidly. On the other hand, elements such as radium, which lodge in bones, are extremely dangerous are known to induce malignant bone tumours and also cause leukaemia –a malignant disease of blood.
In the recent radioactive release–iodine and cesium after the Fukushima nuclear accident in Japan in March 2011, the big worries were expressed. According to Thomas B. Cochran, a senior scientist in the nuclear programme of the Natural Resources Defence Council, a private group in Washington, ‘They imply some kind of core problem.’ The active core of a nuclear reactor splits atoms in two to produce bursts of energy and, as a by-product, large masses of highly radioactive particles. The many safety mechanism of a nuclear plant focus mainly on keeping these so-called fission products out of the environment. Of the two iodine-131 has a half-life of eight days and is quite dangerous to human health. It absorbed through contaminated food, especially milk and milk products, it will accumulate in the thyroid and cause cancer. Located near the base of the neck, the thyroid is a large endocrine gland that produces harmones that help control growth and metabolism.
Likewise, over the long-term, the big threat to human health is cesium-137, which has a half-life of 30 years. It takes over 200 years to reduce it to one per cent of its former level. ‘It is cesium-137 that still contaminates much land in Ukraine around the Chernobyl reactor.’ Cesium-137 mixes easily with water and is chemically similar to Potassium. It get metabolised in the body and can enter through many foods including milk. After entering cesium gets widely distributed, its concentrations said to be higher in muscle tissues and lower in bones. Thus, the nuclear power is a proved health hazards not only for plant workers and nearby dwellers permanently that but also for the whole of humanity in case of nuclear explosion or of nuclear plant accident.