Environtmental and Global Health

Archive for the ‘Radiation’ Category

As can be seen from the above, the best way to prevent internal radiation risks is to avoid contamination, and if it is presented, exercise control to the radioactive material does not enter the body.

To prevent pollution should be managed sources, both the open and the sealed, with care and the tools that each requires by its nature. For example, the sealed source must be managed to avoid trying to hit, rub, suffer chemical attack or fire, or is subject to external forces that may cause the rupture of its capsule.

To verify the physical integrity of a sealed source is practiced called leak test. There are several types of leak test, but the most common, if the source is not very high activity, is to rub the source or the surrounding areas with a cotton or paper towel, preferably impregnated with a solvent such as water or alcohol . This cotton is placed in a test tube or plastic bag properly labeled and identified clearly. Then sent to a specialized laboratory where its activity is measured with sensitive equipment. Read the rest of this entry »

Internal radiation is when radioactive source is inside the body. You can enter the body through ingestion, inhalation, absorption through the skin or by contact with an open wound.

The damage depends on the type of radiation emitted, their energy, the organ that is located and its permanence in the body. By high specific ionization, the alphas and betas in this case constitute a high risk, as a small quantity of emitter material can deposit a highly localized high dose. Read the rest of this entry »

As mentioned before, the specific measures of protection against external radiation are based on the judicious use of three factors: time, distance and shielding.

Protective measures are initiated from the planning work to develop. Firstly there is the selection of appropriate sources and detectors suitable for the type of radiation. The activity of the source and the radiation energy must be the lowest possible for the specific application. The source must be sealed unless there is a particular reason why not. If possible, you should ensure that the physical and chemical nature of the radioactive substances contained in the source to minimize the risks if swallowed in case of breakage of the container. Read the rest of this entry »

External radiation means which receives the body due to sources outside it, usually sealed. The dose received depends on the type of radiation and its energy (hence its power of penetration).

In general, the alpha particle emitters are not considered important external risk because they do not penetrate but a few microns of the skin, and any material the thickness of a paper or a few inches of air, absorb them. The emitters of beta particles are more important for the higher penetration power of the betas in tissue, a few millimeters. Read the rest of this entry »

Man has always been exposed to a certain amount of background radiation from natural sources and manmade sources. Mention some of these sources and the dose levels we provide for comparison with the RHS.

Natural sources of radiation received approximately 1.0 mSv (100 mrem) / year. A natural source is cosmic radiation that comes from off the planet. The atmosphere serves as a shield for most of it, but either way we get a dose of about 0.35 mSv (35 mrem) / year in Ecuador to sea level. This dose increases with latitude due to Earth’s magnetic field, until at latitude 50 °, are approximately 0.5 mSv (50 mrem)/year. Note that these values ??are about 1/100 of the LDE. The dose also increases with height above sea level because there is less atmosphere to absorb radiation. A 2 000 meters above sea level, increases to 1 mSv/year, while 5 000 meters reaches 3 mSv/year. In a transatlantic air travel, are received about 0.05 mSv. Read the rest of this entry »

INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION (ICRP) is an organization established to recommend safe practices on the use of radiation. On several occasions has issued recommendations, which have varied as more experience is obtained on the subject. Currently accept the following general recommendations:

a) not to adopt any practice involving radiation unless it produces a net benefit.

b) The radiation exposures should be kept As Low As Reasonably Achievable (ALARA).

c) The equivalent dose received by any individual should not exceed the limits defined by the ICRP for each circumstance.

Any use of radiation necessary to adopt these recommendations whose emphasis is on keeping exposures as low as possible, in view of the product identified as biological effects of radiation, not to exceed the thresholds defined in each case. Read the rest of this entry »

Radon occurs in nature mainly in the gas phase. Consequently, people are mainly exposed to radon in the breath of air.

Background levels of radon in outdoor air are generally quite low, but in enclosed areas for radon in the air may be higher. In homes, schools and buildings radon levels are increased because radon enters buildings through cracks in foundations and basements.

Some of the deep wells that supply our drinking water can also contain radon. As a result a number of people may be exposed to radon in drinking water, as well as through breathing. Read the rest of this entry »

Chemical element, symbol Rn and atomic number 86. Radon gas is an emanation of radioactive decay product of radium. It is highly radioactive and decays with the emission of energetic alpha particles. It is the heaviest element of the group of noble gases, or inert, and, therefore, is characterized by its chemical inertness. All its isotopes are radioactive with short half-life.

In addition to its three natural isotopes, radon has 22 others have been synthesized by nuclear reactions artificial transmutation made in cyclotrons and linear accelerators, but none of these isotopes have a life so long as the 222Rn.

Any surface exposed to 222Rn is coated with an active deposit consists of a group of short-lived products subsidiaries. In the radiation of this deposit is active energy rays alpha, beta and gamma. Read the rest of this entry »

Ionizing radiation and cancer

Ionizing radiation behave as a carcinogen demonstrated dose-dependent and without a threshold for which small carcinogenesis, ie doses, even daily, can lead to cancer accumulate.

When it comes to exposure to large doses, the time profile of risk differs by type of cancer: the risk for leukemia increases rapidly in the early years, declining thereafter; in solid tumor risk increases slowly over time.

On the general population, and excluding the radiation from X-rays and medical examinations, the increased risk expositional comes from radon decay of uranium. Although you can not completely avoid exposure to household radon, it can be decreased, the simple house ventilation dramatically reduces radon levels inside. Read the rest of this entry »

Natural radioactivity. Resulting from the inherent instability of a number of atoms in nature (uranium, thorium, etc.) as well as from cosmic rays – the latter exposure is greater in the regulars on the plane .

Radioactivity incorporated in foods, beverages, etc. Marine crustaceans and molluscs (mussels, clams, mussels) the particular focus. Read the rest of this entry »