What are radionuclides and what is their role in the world around us? How do they affect the physical universe? How do they affect living organisms? And for a person? What are radionuclides in terms of biology and medicine? These, as well as a number of other questions, will be considered within the framework of this article.
Introduction
Many people are afraid of radioactive products, being irradiated with isotopes during medical procedures, being in conditions of high radioactive background. Understanding the impact of these factors can often be described as very abstract. It often comes down to a simple statement: all this can cause serious illness.
But which ones? Why do they arise? What is the mechanism of their progression? Let's see what radioactive elements are and how they affect the body.
What are radionuclides: definition
Start with terminology. Radionuclides areradioactive atoms, which are characterized by a certain (usually indicated) mass number and number. For isomeric representatives, one should also mention the energy state of the nucleus. An atom is a complex system, it consists of particles-waves of three categories: protons and neutrons in the nucleus, as well as electrons surrounding it, which form a shell. In terms of mass, there is a significant advantage. Almost all of it is in the core.
By the way, protons and neutrons make up the mass of a nuclide. Which of them can be in different nuclear energy states. One of them is represented by isotopes - these are nuclides that have the same number of protons. Another state is isobars. In this case, the atoms have a different number of protons and neutrons, although the same mass value is observed. This is what nuclides and radionuclides are.
About applications
Man uses radionuclides in the economy, science, technology and medicine. Thanks to them, it is possible to study biochemical and physiological processes in the normal state and in the event of pathologies. They also help in studying the patterns of exchange and migration of chemical elements in the body and the environment.
In medical practice, radionuclides are invaluable in the diagnosis and subsequent treatment of various diseases. They are also used for sterilization of various products, materials and medicines. We have considered what radionuclides are in general terms, now let's pay attention to special cases.
Iodine
Oneof the most famous representatives. Its specificity of action depends on the half-life. According to this criterion, short-lived (J-131) and long-lived (J-137) isotopes are distinguished. But the probability of meeting the first is an order of magnitude greater than the second. Radioactive iodine Y-131 can enter the human body with food, through burns and wounds, during the breathing process. But basically it happens through the first and last accumulation options. A distinctive feature of this element is that it is extremely quickly absorbed into the lymph and blood.
It has the ability to accumulate in the thyroid gland, bones, muscles and liver. Some thyroid diseases lead to an increase in the scale of this process. It is believed that the lethal concentration of this radionuclide in the body is 55 millibecquerel per kilogram. At lower doses, negative pathological changes simply occur in the immune and hematopoietic systems, the thyroid gland, and metabolism is disturbed.
Regarding the impact of this radionuclide, one must always be aware of the short half-life. In other words, the negative effect is felt in the first days after radiation contamination.
Cesium and strontium
These are isotopes that are harmful to he alth throughout human life. It is they who pose the greatest danger to those who live in the contaminated area. In addition to cesium and strontium, transuranium isotopes should also be mentioned. They mainly enter the body through food. Their influencedepends on a number of factors.
Radionuclides in the human body are harmful, and the degree of damage depends on:
- Age. Children are the most affected.
- Paul. Men are more likely to accumulate radionuclides than women.
- The physiological state of the body.
- Concentrations of isotopes in consumed foodstuffs. Most of them are found in berries and mushrooms.
- Structural and functional features of tissues and organs.
- Influence of the factors of assimilation (attachment) and removal of radionuclides from a person.
Although a little clarification about gender should be made here. During pregnancy, women are characterized by an increased ability to accumulate radionuclides. However, they usually occupy the placenta. And this often turns into hormonal disorders, which are observed in both the fetus and the mother. This affects the subsequent development, first of all, of the child. The placenta is the main barrier for radionuclides to reach the fetus.
But if it is damaged (if there are a lot of isotopes), the fetus dies. If we talk about different organs, it should be noted that two types of changes can occur in them: metabolic and structural. The danger from them is unequal and strongly depends on how exactly radioactive elements are accumulated in specific cases.
A small digression about physical properties
It is necessary to ask a question thatno, what is the specific activity of radionuclides? This means the indicator of study (the number of decays) in relation to the mass of the source substance, per unit of time. In this regard, it is important to understand what the specific effective activity of natural radionuclides is. This parameter is used to test the safety of the conditions in which people will have to live. For example, the study of building materials from which the construction of a building is planned.
More about the effect on the body
It has been experimentally proven that under the influence of radionuclides pathological changes occur in the heart, kidneys, liver, endocrine, reproductive, nervous, hematopoietic and immune systems. Let's go through these points in more detail:
- Cardiovascular system. Functional changes are mainly associated with blockade of various departments and myocardial damage. It should be noted that the influence of natural radionuclides can manifest itself even at preschool age. As the accumulated amount of compounds in the human body increases, the situation will worsen. We should not forget about the harmful effects on the heart muscle directly and indirectly (as a result of damage to the autonomic nervous and endocrine systems).
- Kidneys. Exposure to radionuclides inevitably leads to the death of tubules and glomeruli. And this turns into a decrease in renal filtration. In this case, the content of protein metabolism products (these are urea and creatinine) increases in the blood. Mainradionuclides under the influence of which this happens are cesium isotopes.
- Liver. The accumulation of cesium in it contributes to the occurrence of cirrhosis and hepatosis.
In general, disruption of the endocrine system, kidneys and liver changes metabolic processes. This affects the biochemical picture of the blood. And all because of radionuclides.
Features of influence
A feature is the complexity of influence:
- Immune system. The influence of radionuclides leads to a decrease in the functional activity of competent cells. Because of this, the scale of infectious and parasitic diseases is on the rise.
- Hematopoietic system. With the accumulation of significant doses, the level of erythrocytes in the blood decreases, and large-scale disturbances in the process of formation of blood cells begin.
- The thyroid gland. The process of hormone production is disrupted. The main impact of radionuclides on this organ is inflicted in the first days, although the subsequent effect should not be discounted.
- Pathologies of the reproductive system. First of all, this applies to women. Their occurrence is associated with the effect of radionuclides on the thyroid gland. There is an imbalance between estrogen and progesterone, an increase in the amount of cortisol and a number of other complications.
Does this mean everything is terrible?
Radionuclides really have a negative impact on the human body. But they are afraid of this, unless, of course, a person accidentally wandered into a fresh nuclear funnel, it is not worth it. Worth discoveringone secret: the sources of radionuclides around us are present in huge quantities. They are in the ground, building materials, and many other places. The norm is the amount of radioactivity up to 20 microroentgen per hour.
Although in some areas (in France or India) people manage to comfortably exist all their lives even at rates of thousands of microR/h. Man is constantly exposed to them. So being careful is good. But being paranoid is overkill. If you are very concerned about this issue, then you can begin to actively consume foods that contribute to the removal of radionuclides from the body. For example, milk and rice.
So we looked at what radionuclides are in the human body, the specifics of their manifestation and discussed the realism of the danger for the average citizen.
