Human beings have always been exposed to natural sources of radioactivity, such as the subsoil, water or radon gas. More recently, artificial sources from atomic tests, some medical devices and also building materials have been added.
What radioactivity is
The ionizing radiation or radioactivity is a physical phenomenon of some physical elements that disintegrate spontaneously in more stable elements. In this process high energy particles are emitted (alpha, beta, gamma, X and neutrons), that have the property of crossing opaque bodies or ionizing gases.
At home, the most important radioactivity measurements are gamma radiation and radon gas as the source of alpha radiation.
Gamma radiation has a high energy level and is very penetrating in the human body. The serious damage it causes to cells is used in medicine and food to sterilize, i.e. to kill bacteria.
Alpha radiation has greater energy power than gamma radiation, but is less penetrating. However, it usually enters the body from breathing radon gas.
Radioactivity has an ionizing effect, that is, carries enough energy to liberate electrons from atoms in the cells of the human body, so that unwanted chemical reactions can occur. These can cause alterations in the chromosomes and membranes of the cells. The subsequent fragmentation and reproduction of these cells can extend these alterations to the genetic material (DNA).
The negative effects caused by radiation in the organs and tissues depend on the dose received or absorbed. The damage that can produce an absorbed dose depends on the type of radiation and the sensitivity of the different organs and tissues.
Low doses of continuous ionizing radiation over time are sufficient to increase the risk of long-term effects, such as cancer or brain damage to the fetus. This phenomenon is known as the Petkau effect. For this reason, it is advisable to avoid possible radioactive elements at home, even if they are low-emission.
The World Health Organization (WHO) describes radioactivity as a carcinogen due to the serious damage that it causes to the skin and to the organs.
The dose of radiation received in a natural environment may be increased in some buildings because of the building materials. It is convenient to avoid radioactive materials as far as possible in order to avoid long-term effects.
In general, construction materials made of waste or more recent formation stones, such as volcanic stones, contain larger radioactive elements: Thorium-232, radium-226 and potassium-40. Among these elements we can find granite, bassalt or concrete, to which fly ash has been added.
On the other hand, materials of organic origin such as wood, or sedimentary stone derivatives like natural gypsum or limestone sand provide low radioactivity values.
Therefore, the raw material is the main factor which states the emission of radioactivity in construction materials like bricks or tiles.
The measurement of radioactivity includes the measurement of the pulse rate as well as the measurement and recording of radon concentration.
Radioactive pulses from construction materials, equipment and installations suspected of radioactivity are measured. Different measuring devices can be used, the most common being the Geiger-Müller counter tube or the scintillation counter.
In bio-construction it is considered that inside the house the measured values of radioactivity should be at most 50% of the values obtained in the local natural environment.
want to measure radioactivity?
want to measure radioactivity?