It is true that unprotected medical radiation can have terrible effects on the human body, but medical tests such as X-rays and CTs are not actually terrible when used properly and within reasonable limits.
With the continuous development of medical technology, people are exposed to an increasing variety of medical examinations. At the same time, there is also concern about the safety of the use of screening equipment.
For example, the commonly used X-ray medical examination and treatment, some people believe that they will be exposed to them will cause damage to the human body, the loss is not worth it; some people believe that the use of X-ray equipment, will cause adverse effects on the surrounding environment. Is this really the case?
What is “radiation”?
Radiation is a physical term that is generally divided into two categories, ionizing radiation and non-ionizing radiation, based on the level of energy and the ability to ionize materials.
Ionizing” refers to the process of physical and chemical changes that occur in certain tissues when an organism is exposed to radiation, resulting in damage.
Non-ionizing radiation is weaker in energy and has no ionizing ability, for example, electromagnetic waves emitted by cell phones, computers, microwave ovens, communication base stations and other devices are of this kind.
In general, exposure to these non-ionizing radiation, relevant scientific studies have not found evidence of damage to the human body.
X-rays used in medical examinations, on the other hand, are ionizing radiation that has the ability to ionize and may affect human health.
X-rays are a big help to humans
The most common use of X-rays in life is in medical examinations, such as X-ray films and CT scans, which take advantage of the physical properties of X-rays.
X-rays, like sunlight and radio waves, are beams of energy that are short in wavelength and high in energy and have a penetrating effect. Therefore, the use of X-ray photography can reveal many lesions inside the body, providing doctors with very valuable and accurate diagnostic information and playing an important role in the treatment of diseases.
In particular, the creation of the X-ray device “CT” has greatly improved the difficulty of diagnosing brain diseases and has saved countless lives.
Effects of ionizing radiation on the human body
The damage caused by ionizing radiation is divided into random effects and non-random effects (generally called deterministic effects).
The random effect is very small, and except for a few special cases, it does not occur in daily life or during medical treatment.
What is relevant to our medical treatment is the non-random effect, that is, the deterministic effect, and there is a correspondence between the severity of the deterministic effect and the radiation dose.
Deterministic effect is an effect with a “threshold”
Radiation must reach a certain dose in order to cause damage to the human body, and this dose is called the “threshold”. If a person is exposed to radiation below the threshold dose, it is considered not harmful to the body; if the threshold is exceeded more, the higher the severity of the harm.
In medical examinations, the use of X-rays is strictly controlled within a safe range, much smaller than the dose threshold mentioned before, and therefore does not cause significant damage to the human body.
How is the radiation dose measured?
Because different biological tissues have different sensitivities to radiation, the health risks to different parts of the body vary when exposed to radiation.
In order to clearly describe this situation, scientists introduced the concept of “effective radiation dose”, and developed a unit millisievert (mSv in Chinese) to measure it.
With the concept of “effective radiation dose”, the radiation risk can be better quantified, so as to better reduce the harm of ionizing radiation to the human body.
Natural radiation is everywhere
Radiation is also ubiquitous in the natural environment we live in, including cosmic rays coming to Earth and rays emitted by natural radionuclides in nature, so these are called “natural background radiation”, also called “natural background radiation”. According to the statistics of relevant institutions, the amount of “natural background radiation” a normal person receives in a year is about 3 mSv.
This radiation dose is not fixed, and may vary slightly depending on natural conditions (e.g. altitude, sunlight hours, etc.), so the average value of 3 mSv is used as the measure in this article.
After understanding the “natural background radiation”, we can simply quantify the dose of various medical examinations. For example.
The dose of a chest X-ray is about 0.1mSv, which is equivalent to the “natural background radiation” a person receives in 10 days;
The dose of an X-ray of the extremities is about 0.001 mSv, which is equivalent to the “natural background radiation” to which a person is exposed in 3 hours.
This shows that timely, accurate and risk-controlled radiation examinations can facilitate the diagnosis and treatment of patients’ diseases, and the advantages far outweigh the disadvantages in this process.
Medical radiation is safe and controllable
Based on the physical properties of X-rays, i.e., their intensity decreases when they penetrate any substance, a series of safe and reliable protection programs can be developed.
Adequate shielding (shielding material) between the radiation source and the human body can block the radiation, ensure personal safety and achieve the purpose of protection. Therefore, the main point of shielding protection is to place shielding materials that can effectively absorb radiation between the radiation and the human body.
1. In terms of public protection, the common shielding materials used to block X-rays are lead plates, concrete walls, or barium-containing cement walls.
As a user of X-ray equipment, you need to do a good job of these protective measures, but also through the acceptance of a number of relevant departments. Now, China’s management of medical radiation has been quite safe, the use of X-ray equipment, the physician operating the equipment and the surrounding environment generally will not cause impact.
2, in terms of examinee protection, the measures often taken is to shield the non-examined parts.
As a patient, when undergoing radiation examination, you can ask the radiographer to give appropriate shielding protection, such as wearing a lead suit, lead bib, lead cap, lead apron, etc., to avoid unnecessary radiation to sensitive organs.