Radiation protection, a young discipline, of little more than a century of tradition, which deals with us humans, yes, because it is the study, and prevention, of harmful effects that radiation has on our body.
For well-understood technical reasons, such a science could only be born following the discovery of X-rays, towards the end of the 1800s. Over the years, the action of radiation protection give her ionizing radiations discoveries and inventions have arrived. An example for all is the refinement of the calculation of the absorbed dose, then the application of the dosimetry. Meanwhile, the measurement methods have become more and more precise and faster. And sure, to make us so.
The main fields of application of the radiation protection I'm "Radiation protection of workers"During work,"Patient radiation protection"Linked to diagnostic tests, and"Radiation protection of the general population"... all other cases that do not fall into the previous categories. The three general principles of the radiation protection are the justification, optimization and application of dose limits. Let's see them, to understand how we are protected and why. And how much.
Radiation protection: justification
The justification: a bit like at school, the radiation they must justify themselves, or rather, those who use them must do so. This means in practice that a prior assessment of the risks and benefits is required to ensure the radiation protection, and above all the latter must be clearly superior to the former. This also in the medical context.
"Medical exposures must be shown to be sufficiently effective by evaluating the potential benefits they produce, including the direct benefits for the health of the person and the community, compared to the damage that exposure could cause" reads the law Legislative Decree 187/00.
Also at the center of recent controversies about useless or presumed medical examinations, it is known that in advanced countries more than 20% of carried out medical exposures are not necessary (UNSCEAR 2000). This is a data that is not up to date, today it could be different, but the problem remains for the radiation protection: many radiological investigations are repeated in vain.
Radiation protection: optimization
Optimize, in the field of radiation protection, means doing everything to ensure that exposure to radiation is minimized. We are not asked to do the impossible or to perform miracles but to act on some radiation protection parameters in an effective way.
One of these is the distance from the radiation source: by naturally moving away the risk collapses. But how? Generally like the inverse of its square. In addition to the "space" in the radiation protection the exposition time: that it is the minimum. Compatibly with the usefulness that radiation must have, but not a microsecond more. Once you have fixed space and exposure time, you can also optimize by predicting adequate shielding.
There radiation protection also deals with these and suggests their ad hoc design based on the type and intensity of radiation to be shielded. Finally, a moment of control of radioactive contamination is also necessary, dutifully kept within very low levels.
"Exposures must be kept at the lowest level reasonably obtainable, taking into account economic and social factors" (Legislative Decree 187/00). Our law that speaks of radiation protection says so. Easy to say, however, because to optimize they are necessary radiological equipment recent and advanced procedures. This requires economic resources and time.
This aspect has naturally aroused controversy, arm of strength and ping pong of opinions in front of one ideal radiation protection and to a “de facto” one, with the tools, the technical and personal resources and the money really available. In hospitals as elsewhere. An ever-changing issue that is not our task to deal with. By reading here, we have the basis to form an opinion and deepen.
Radiation protection: limits
The third general principle of radiation protection deals with dose limits, those imposed by current national legislation, concern exposed workers and also “the population” in general, including us. The workers have "special doses"Compared to the others, they can be exposed workers of category A (the most exposed) and category B: it is an assessment that radiation protection practices make based both on the type of work normally performed, and on the potential exposures linked to anomalous events or malfunctions. Often being the most needy subjects radiation protection, workers, primarily if they are class A, must be subjected to health surveillance by specialized and licensed doctors.
Somewhat special compared to the "typical" citizen are also the patients who undergo some medical tests. For them i are defined Reference Diagnostic Levels: Dose levels in medical radiodiagnostic practices or, in the case of diagnostic nuclear medicine, levels of radioactivity, for typical tests for groups of standard-sized patients and for types of equipment.
Radiation protection and ionizing radiation
There radiation protection she is bound, awake, and studies ionizing radiation and effects. Let's see in practice where these radiations come from by exploring their sources, both natural and artificial. They can be cosmic radiation: they are generated by high-energy particles and gamma rays arriving from space and which, interacting with the atmosphere, produce ionizing radiations.
These are of type corpuscular or electromagnetic and they increase at high altitude, when the atmosphere protects us less. There radiation protection also warns us against terrestrial radiation: another ionizing radiation this time due to the decay of radioisotopes present in the earth's crust.
We come at artificial springs: here we move from equipment such as X-ray tubes to others such as accelerators. They are certainly not household appliances, but we find them either in industries, or in the medical field.
A mention also to non-ionizing radiation since they exist and also have induced effects. Let's see if they need the radiation protection. It seems so, to date, because we have lived with the non-ionizing electromagnetic spectrum emitted by the sun and other celestial bodies for years, but today the intensity of artificially produced radiation has increased.
Radiation protection comes into play and is activated in the field of protectionism and the need for regulation in this regard. For clarity, the non-ionizing radiation they are those not able to produce ionization in the materials exposed to them. They are called NIR, acronym, and a well-known example is that of radio waves.
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