Ionizing radiation is very beneficial to society in many fields, but its negative effects are a matter of concern. Therefore, there is legislation to control exposures to this radiation and regulations to adopt preventive measures.
Before we begin to look at some basic prevention measures, we must bear in mind that radiation propagates in electromagnetic waves and if it has sufficient energy to cause ionization, it is called ionizing radiation.
Therefore, whenever we talk about radiation, it must be related to the energy that is transmitted through space and interacts with matter, modifying it and altering its original state.
This is important, since they are capable of altering even the large molecules of organic tissues such as DNA or proteins. This is why it is important to be aware of this radiation and to protect ourselves.
How is ionizing radiation classified?
This type of radiation consists of photons with high energy, high frequency, which are capable of breaking molecular bonds. Ionizing radiation can be classified according to its origin and properties.
Within this group are gamma radiation, alpha radiation, beta radiation and X-rays.
For example, Gamma Rays are the highest energies with frequencies above 3-1016Hz and their source is natural. While X-rays are artificially made and their energy range is lower, so they are more commonly used.
Therefore, exposure to ionizing radiation can come from a professional activity or naturally from radiation in the environment.
The humans receive radiation on a daily basis by cosmic radiation, coming from space, and radon radiation, coming from the earth. These harmful substances are received in very small quantities and will vary depending on the place where we live.
On the other hand, artificial radiation may be received by professionals as a result of their work or by people requiring diagnosis. The use of ionizing radiation in the health field is mainly focused on Radiodiagnosis, Radiotherapy and Nuclear Medicine services.
Factors to be taken into account when protecting yourself from ionizing radiation:
In order to know how to protect yourself from radiation and mitigate the consequences of radiation, you need to know:
- The type of radiation, since each type behaves differently with matter.
- The energy of the ray
Thanks to these data it will be possible to define the material to be interposed between the radiation and the person as well as its thickness.
In addition, all exposures to this type of radiation can be given as follows:
- Planned exposure: When a radiation source is to be used.
- Emergency exposure: For example, due to a nuclear emergency.
- Existing exposure
Basic protection measures:
The objective is to have an appropriate level of protection without limiting beneficial radiation practices.
These standards of protection and prevention seek to keep the radiation dose below a certain limit.
To this end, the principles of the Radiation Protection System proposed by the International Commission on Radiological Protection (ICRP) are as follows:
- Justification: No radiation exposure unless it involves benefits for the exposed people and compensates for the detriment caused.
- Optimization: Protection is optimized to keep the magnitude of individual doses, the probability of exposure and the number of people exposed as low as reasonably achievable.
- Dose limitation: Following the term ALARA (“As Low As Reasonably Achievable”).
Radiation protection standards will be specific to each facility depending on the type and magnitude of the risk:
- When there is a risk of irradiation:
- Limit the exposure time. the dose received is proportional to the time of exposure.
- Increase the distance to the source, since the dose decreases inversely proportional to the square of the distance.
- Shielding: Both structural (shielding of equipment and installation, confinement of the source) and personal (personal protective equipment). Recommended protective aprons and goggles for the crystalline lens and thyroid protector.
- When there is a risk of external contamination: Personnel should be familiar with the operating regulations of the radioactive facility, which will contain information on work procedures, preventive measures to be taken, decontamination and waste disposal systems and the emergency plan.
- The specific measures for protection against radioactive contamination depend on the radiotoxicity and activity of the radionuclides and are established by acting both on the structures, installations and work areas and on the personnel, through the adoption of safe working methods and, if necessary, the use of appropriate personal protective equipment.
The workplace must delimit and signpost the different work areas.
After a previous evaluation, the workplaces will be classified according to the risk of exposure and taking into account the probability and magnitude of potential exposures, in the following zones:
- Guarded Zone: Delimits an area with LOW radiation intensity, there being the possibility of receiving effective doses higher than 1mSv per year. Its access must be limited to authorized staff who have received training and instructions appropriate to the existing risk.
- Controlled Zone: Delimits an area with MEDIUM radiation intensity. Any area with a risk of having doses higher than 6mSv per year. Access will be limited to authorized people that have received training and instructions appropriate to the existing risk, in accordance with the work procedures established in writing.
- Limited stay zone: Delimits an area with HIGH radiation intensity. If a person remains in this zone, he/she could receive a dose higher than the annual limit (20 mSv).
- Limited stay zone: Risk of receiving in short periods of time a dose higher than the limits.
- Prohibited access zone: Risk of receiving, in a single exposure, doses in excess of the annual dose limits.
Types of workers:
Workers are classified into two categories:
- A: those likely to receive an effective dose in excess of 6 mSv per official year, or an equivalent dose in excess of 15 mSv per year for the lens or 150 mSv per year for the skin and extremities. Exposed workers in category A are required to use an individual dosimeter.
- B: they do not need to compulsorily use individual dosimeters, provided that it can be guaranteed that their exposure to ionizing radiation can be assessed by monitoring radiation levels (Area Dosimetry).
Vigilance:
Radiation monitoring of workplaces in controlled and monitored areas shall include measurement of external dose rates and measurement of activity concentrations in air and surface contamination.
For category B workers, they are responsible for the use and change of the dosimeter. In addition, the reading of the dosimeter must be done manually and a record must be kept for each worker until he/she has reached 75 years of age.
On the other hand, they must submit to a health examination prior to the start of the activity and reviewed annually.
Training:
Exposed workers must have training appropriate to their responsibility and risk of exposure.
If you or your company need more information about dosimeters or radiation protection tools, do not hesitate to contact us without obligation.
