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> Mutations - Radiation Issue: 2011-3 Section: University

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Nowadays, the use of mobile phones is widely said to be harmful and dangerous for human health. It is already known that the emitted radiation might have serious consequences on the organism, but what radiation is in fact, whether ionized or not, and in which way it harms our organism, is a question of high significance these days.

Radiation is an energy which is transported in wave-like and particle-like properties. Examples of

radiation in everyday life are microwaves, radio, television, and the x-rays used in medicine.

Some chemical elements emit ionized radiation, which means they convert an electrically neutral atom into either a positive or negative ion, with the addition or the abortion of electrons.

 

CONSEQUENCES OF RADIATION IN THE ORGANISM

Radiation causes ionization to the molecules of alive cells. In small doses of radiation, like the ones we receive every day, cells recover from the damage easily. In higher doses, up to 100 rem, cells may not be able to recover the damage and this is why they might die or change their permanent form. Most cells that die are of low importance and our organism can easily replace them. However, the ones that are mutated form irregular cells which, in some cases, may be carcinogenic. So this is the origin of our increased concern over concern if someone is constantly exposed to radiation.

In even higher dose, cells cannot replace themselves and the tissues cannot function. If the doses increase (>300 rem), then problems are created to the immune system and the organism cannot fight the diseases and the contamination. In the highest doses of radiation, and if medical care is not provided, 50% of the patients die in 60 days time.

 

MUTATIONS AT THE GENETIC MATERIAL

In some cases, radiation may not manage to make the cell die, but to alter the DNA in a way that can leave the cell alive with a modified DNA. The DNA molecules are extremely long chains of atoms, wrapped around of proteins and organised in structures, the chromosomes, in the cell.

Great damage to the DNA is caused by gamma rays, which, if they go through the cell, ionize the atoms. This means they enable the removal of electrons from them, forming positive ions or charged atoms. The molecules near the DNA are likely to be ionized and to react, causing the break of chemical bonds and the rearrangement of its elements. This DNA disruption at the body cells will have a minimal influence on the human descendants. However, it will cause disorders to the cell divisions (mitosis, meiosis) so, it can generate cancer.

However, if the ionization happens in genetic cells, like spermatozoa or/and ova, the damage might be more serious and genetic mutations usually appear at the descendants of the organism. The main symptoms that the descendants can have is hexadactyly, which is the development of a sixth finger in the hand or foot, and the lack of the pigment melanin, which is the modification of one of the genes that control the production of a pigment, the melanin.

 

NUCLEAR ACCIDENTS

Nuclear power plants generate high portions of ionized radiation during the fission of the operation.

This way, atomic energy is released, which is nowadays used by some countries for the production of electric energy. In addition, it is used for war and for the construction of the atomic bomb.The nuclear fission products are radioactive and any explosion could turn fatal for the land.

The main alive examples of the effect of radioactivity are the two atomic bombings in Nagasaki and Hiroshima, and the nuclear accident of Chernobyl, Ukraine, as well as the recent accident in Japan. The first case refers to the Second World War. In August 1945, Americans use for the first time the atomic bomb in the Japanese cities of Hiroshima and Nagasaki, leaving the whole humanity speechless. Until today, victims have surpassed the 220.000 and the genetic mutations of the next generations have been tremendous. Apart from the casualties, there were a lot of people radioactively poisoned. The environment, the air, the ground, food and water were polluted, but also the clouds transferred the pollution to nearby areas.

The nuclear accident in Chernobyl happened in 1986 and it still has an obvious impact on the health of the people in the area and on the environment. The radiation exceeded the Ukrainian boundaries and even reached Sweden. The genetic and the teratogenetic cases increased a lot. Meanwhile, in Ukraine, the percentage of cancer was multiplied by a thousand in 10 years’ time. Many of the actual residents in the area grow old earlier and develop several kinds of problems. In addition, centuries are estimated to be needed until the atmosphere is cleaned by the radiation released in 1986.

However, one of the most important and recent accidents is the one that happened in the nuclear station on

Fukushima, Japan in spring 2011. The catastrophe came as a consequence of the 2011 Sendai earthquake and the tsunami that followed. The old installations, the insufficient security system and the bad conservation of the plants were the main factors of the accident. It is estimated that the radiation emitted surpasses by 400 times the annual average and can be compared with the Chernobyl rates. The effects on the residents’ health will be really harmful and it is almost certain that they will suffer from several kinds of cancer and long-term problems.

Nevertheless, humans have now started to learn

from their mistakes and take more precautions concerning the use of energy that can have radioactive results. The security measures have increased, as a similar event could have catastrophic consequences affecting all humanity.

 

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Vasiliki Samara :: 26/06/2012 :: Pageviews: 3239