lunes, 6 de junio de 2011

Radioactivity

WHAT IS RADIOACTINITY?


The radioactivity is a natural or artificial, by which some substances or radioactive chemical element, are able to emit radiation, which have the property to impress photographic plates, ionized gases, to produce fluorescence, through opaque to light ordinary, etc. The radiation emitted by radioactive substances are mainly alpha particles, beta particles and gamma rays. Radioactivity is a nuclear power, used in medicine (radiotherapy) and consists of some atoms like uranium, radium and thorium are "unstable", and constantly lost alpha, beta and gamma ray (X).

Natural radioactivity is the process whereby heavy and unstable nuclei of some radioactive materials disintegrate spontaneously and produce new nuclei of new elements and release energy.
It consists of artificial radioactivity in the breakdown of stable atomic nuclei through the slightly accelerated particle bombardment, giving rise to new kernels that correspond to new elements.


In 1898, the Curies dedicated to the study of the radiation observed by Becquerel (physical) discovered two new radioactive elements: polonium and radium, characterized by:



  • Ionized gases



  • Impress photographic plates



  • Cause flashes of light in certain substances.



RADIATION CHARACTERISTICS OF THE PHENOMENON.


The emission of radiation by a radioactive material depends on the state of freedom or combination is found, ie a substance can be as simple or as part of a compound and this fact will not affect those emissions.

Radiation is independent of factors involved in chemical reactions.

Radiation can impress photographic plates, through opaque materials, ionizing gases and chemical reactions.


TYPES RADIATION CAN BE:



  • Alpha rays (a)


These rays consist of material particles which have two positive charge units and four units of mass. They are slightly deflected by the action of strong magnetic forces. Can ionize the gas and penetrate the area. Are arrested or absorbed when placed before them a metal blade. Initial velocity varies from 109 cm. / S to 2 x 109 cm. / S.


  • Beta rays (b)


The particles that make up the Beta rays are of lower mass than the alpha rays are negatively charged unit. Are projected at high speeds, although this depends on its source and are sometimes issued at a speed approaching that of light (3 × 1010 cm. / S).



  • Gamma (g)


Its nature is different from alpha and beta rays, since they do not experience diversion by electric fields and / or magnetic. Despite having a shorter wavelength X-rays, act as an electromagnetic radiation of the same nature. Can pass through layers of lead and goes to great distances in air. Its nature is to wave and has no electric charge or mass. Its capacity is weaker ionization compared to alpha and beta rays.


It is undeniable that radiation affects organisms. The can sicken or heal. Can be managed like any medicine, or have lethal effects. Depends on how you use.

We know that the ionization that occurs may lead to chemical transformations in the field. If living matter, these changes necessarily interfere with vital functions of cells receiving radiation. Moreover, as some radiation can penetrate the body, such effects may occur in organs or cells of very different functions.


For a point of comparison, consider a sun burn sun's rays, especially the ultraviolet in the skin produce effects that we all know, once we have felt the sting of a burn from exposure to the sun too long. Is due to chemical changes induced in the skin, which may even kill the cells, as we have all experienced the skin break off useless. Now the skin is designed to support these effects, then, when damaged, can easily be replaced by new cells which in turn assume the vital role of protecting the rest of the body. Ionizing radiation that penetrate the body can cause damage equivalent to the tissues, but not only the skin, but the entire body. Such damage can be permanent if they occur in organs that do not regenerate, as the brain.


The effects of radiation produced in organisms have been classified into four groups: those that cause cancer, genetic mutations, the effects on the embryo during pregnancy and burns excessive exposures. The first two groups usually occur when the doses are small, but prolonged. The third in a stage of life where the organism is particularly sensitive to be reproduced in their cells at an accelerated pace. The fourth case in accidents or nuclear explosions. There have been many studies on how each of these cases occur under different circumstances.


FUKUSHIMA RADIOACTIVITY:


Radioactive levels found in foods around Fukushima
About Fukushima, radioactive levels found in foods
Near the Fukushima nuclear plant, the products have experienced high levels of radiation, explained the government spokesman Minister of that country, Yukio Edan.
"The executive will take the necessary measures. Do not rule out possible limitations in the distribution of products in the area. Do not want to risk "he said.
In addition, detected radioactive iodine in the water of Tokyo and its environs, although low at the moment.
TEPCO said in a statement offering apologies for any inconvenience this has brought the company with central Fukushima.
They have sent specialists to see what extent the land affected was the area where the radioactive release occurred. Accumulate data to take into account to decide and to save as many people as possible.




EFFECTS OF RADIATION IN JAPAN:


Effects of radiation in Japan. The nuclear accident at the plant in Fukushima Daiichi, radiation issue for years, the effects of long-term damage lasaludgravemente and the environment.

According to scientists at the core of a nuclear reactor there are more than 60 radioactive contaminants from uranium fission, a very long life and other very short-lived, but almost everyone has a great affinity with the body and accumulate in him, since they are similar to the biological. Of the 60 pollutants, which would have major consequences for lasaludhumana would be iodine, strontium 90 and cesium (C-137).

Iodine and leave immediately affects mutations in the genes, from which it can develop later, thyroid cancer, as the case of Chernobyl, where they multiplied by ten cases of thyroid cancer in central Europe.

On the other hand, strontium accumulates in the bones at least 30 years, like calcium, and for years continues to radiate the body, while cesium is deposited in the muscles.

Both pollutants increase the risk of all types of cancer, especially bone, muscle and brain tumors, decrease the body's immunity and increase the capacity of having other diseases. In addition, radiation alters reproduction and affects more women than men.

The explanation lies in the fact that the sperm is completely regenerated every 90 days and altered sperm disappears during this period, but the eggs are in the ovaries a lifetime, and if a radiation-altered egg is fertilized, then , will have birth defects, even years later.