RADIOACTIVITY OF PRECAUTIONS. The content in rain and snow of decay products of radioactive elements, mainly radon. Activation of precipitation occurs in two ways: 1) particles of the decay of radioactive isotopes can be condensation nuclei; 2) precipitation can be mechanically enriched with radioactive decay products during fall through the atmosphere. RO can be measured by the intensity of the y-rays they emit during precipitation and by measuring the intensity of the α- and P-rays emitted by the collected sediments in the ionization chamber. R.O. on average is about 10-11-1012 Ci per 1 g of precipitation. Precipitation that falls during thunderstorms and squalls is more radioactive than precipitation. Snow is more radioactive than rain. Dew, frost, frost also detect radioactivity.[ ...]

FALLOUT. Fall on the earth's surface radioactive substances released into the atmosphere during atomic or thermonuclear explosions. Local fallout near the site of the explosion, in the next few hours after it, consists mainly of soil particles, while becoming radioactive.[ ...]

RADIOACTIVE RAIN. Rain, the water of which contains radioactive decay products (artificial) in an amount much higher than usual.[ ...]

The fallout from nuclear weapons test explosions is a completely different type of atmospheric pollution, since their biological effect is determined more by radioactivity than by the toxicity of a given substance. chemical. The effects of radiation on animals are qualitatively similar to those on humans (Hollaender, 1954; National Academy of Sciences, 1956a). The resulting effects can be conditionally divided into immediate and remote ones.[ ...]

Fallout and congenital anomalies. The first evidence of a possible increase in the number of children born with defects caused by fallout radioactive fallout was obtained in the process of research conducted in 1960 in Alberta on the instructions of the Minister of Health of Canada.[ ...]

The radioactive dust that falls on the ground after atomic explosions is called radioactive fallout. The nature of radioactive fallout depends on the type of bomb. First of all, it is necessary to clearly distinguish between two types of nuclear weapons: 1) in the atomic bomb, heavy elements, such as uranium or plutonium, are split, accompanied by the release of energy and radioactive "decay products"; in a hydrogen bomb, which is a thermonuclear weapon, light elements (deuterium) combine to form heavier elements; this releases energy and releases neutrons. Since for thermonuclear reaction very necessary heat(millions of degrees), then. the fission reaction is used to "start" the fusion reaction. In general, per unit of energy released, thermonuclear weapons produce fewer decay products and more neutrons (creating induced radioactivity in the environment) than atomic weapons. The residual radiation, part of which is widely dispersed in the biosphere, leaves, according to Gleston (1957), about 10% of the energy of a nuclear weapon. The amount of radioactive fallout produced depends not only on the type and size of the bomb, but also on the amount of foreign material involved in the explosion.[ ...]

Radioactive fallout from small atomic bombs or nuclear explosions produced for peaceful purposes (building ports, canals or stripping) falls on the ground in a narrow straight line in the direction of the wind, but some of the smallest particles can be carried away over long distances and fall with rain far from the site of the explosion. Although the total radioactivity decreases with increasing distance from the explosion site, it has long been established that some radioactive isotopes that have important biological significance, especially strontium-90, in most found in wild animals at a distance of 100-150 km from the epicenter of the explosion (Nishita and Larson, 1957). This is explained by the fact that 90Sr has two gaseous precursors (90Kr -> -90Nm -> -905r) and is formed relatively slowly after the bomb explosion. Therefore, strontium-90 is included in the smallest particles (less than 40 microns), which settle far from the epicenter and are more easily included in food chains. Cesium-137 also has gaseous precursors and is an essential constituent of the more readily soluble "far precipitation".[ ...]

Release of radioactive Wastewater into the city sewer can cause contamination of these sections of the canal if they lead to an increase in the radioactivity of the sediments and sludge located there, which poses a health hazard to workers maintaining the canal. If the sludge is enriched with radioactive substances, then it cannot be used for fertilizing and improving the soil structure. When used in agriculture radioactive urban wastewater, there is a danger that the radioactivity will pass to the plants and, as a result, grains will be contaminated, as well as livestock feed. Finally, radioactive contamination can also get into the reservoir.[ ...]

Fallouts of radioactive fallout reached Belarus, Russia and regions of Ukraine. These pollutions caused immunity disorders in people and animals - the ability of living organisms to resist the action of damaging agents.[ ...]

The natural radioactive field of the Earth, or the field of ionizing radiation, is observed on the surface and in the near-surface part of the lithosphere. The natural radiation background is formed due to the radiation of radionuclides that are part of the rocks. More than 40% of the dose of natural human exposure is provided by radioactive gases - radon-222 and radon-220 (thoron). However, at present, the intensity of ionizing radiation has increased significantly as a result of the use of atomic energy by man, including for military purposes. Fallen from nuclear weapons testing fallout were perceived by the lithosphere, and the radionuclides of these sediments became, thus, a source of additional radiation.[ ...]

Radionuclides (radioactive substances) in quantities exceeding the natural level of their content in the environment cause radioactive contamination that is very dangerous for humans and natural ecosystems. Among the radioactive elements, strontium-90, cesium-137, iodine-131, carbon-14, etc. are the most toxic for humanity and the entire ecosphere. The main radiation hazard today is radioactive fallout, which was formed from more than 400 nuclear explosions that occurred in the world from 1945 to 1996, accidents and leaks in the nuclear fuel cycle, as well as stockpiles of nuclear weapons and radioactive waste.[ ...]

So the radioactivity environment and the synergistic effects of dust and chemical air pollution may play a much larger role in cancer and other diseases than previously thought. Since 1948, Japan has seen a sharp increase in mortality by 1200% compared to the level observed over the previous 10 years.[ ...]

Months later, radioactive fallout will fall and destroy the gene pool of higher organisms. Inevitably, there will be a decrease in the ozone content in the atmosphere (possibly up to 50%) and an increase in the intensity of UV radiation by dozens of times, which will also catastrophically affect all living things.[ ...]

The significant increase in fallout levels as we approached the Arctic Circle was subsequently confirmed by direct measurements of milk radioactivity in northern Alberta. Milk studies were carried out during May and June 1963 and the following results were obtained: the concentration of a7Cs in milk in the north was 117 and 211 pCi/l, respectively, and in the southern part - 92 and 199 pCi/l.[ ...]

The soil has the ability to accumulate radioactive substances (905g, 14C, Se, etc.), entering it with radioactive waste from nuclear, power and other reactors, regeneration facilities of "hot" laboratories, medical, research institutions using radioisotopes, as well as from atmospheric radioactive fallout from nuclear tests. Of the radioactive isotopes, 905r and 137C8, with long half-lives (28 and 30 years, respectively), pose the greatest danger. Radioactive substances are included in food chains and affect living organisms. Damage to the body can be both individual (for example, the development of malignant neoplasms) and genetic, representing a potential danger to the health of future generations.[ ...]

5.1

Determining the level of environmental contamination by radioactive fallout and measuring the amount of fission products accumulated in the body of animals is relatively easier than other air pollutants. ,AT last years a number of reports have appeared that give the results of measuring the amount of some fission products that occur naturally in animal tissues, as well as in animal products as a result of radioactive fallout (Anderson et al., 1954; Comar et al. 1957; ¡Kulp, Eckelmann and Schu-lert, 1967; Van Middlesworth, 1956).[ ...]

Initially, studies of the possible health effects of radioactive fallout were usually limited to the case of abundant localized fallout consisting of nuclear fission products and radioisotopes produced by the absorption of neutrons. These precipitations reach the ground within a few minutes or hours after the explosion, if it occurred near the surface of the earth. In this case, the doses of radiation will amount to thousands of rads, so there can be no doubt about their great biological danger to human life.[ ...]

With appropriate weather conditions radioactive aerosols present in the air, like other dust particles, serve as nuclei for the condensation of water vapor and then fall out with rain or snow. Thus, radioactive fallout falls as rainfall. Therefore, to determine the radioactive contamination, it is necessary to analyze a sample of precipitation.[ ...]

The main radiation hazard is posed by stockpiles of nuclear weapons and fuel and radioactive fallout, which were formed as a result of nuclear explosions or accidents and leaks in the nuclear fuel cycle - from the extraction and enrichment of uranium ore to waste disposal. The world has accumulated tens of thousands of tons of fissile materials with colossal total activity.[ ...]

Thus, a suspension of microorganisms introduced into the sand in June caused an increase in the radioactivity of the sediment from the water extract by about two times compared to the sediment from unenriched sand.[ ...]

Furnaces of this type have found application for burning waste coal with lime, roasting radioactive fallout, neutralizing sulfite waste to obtain a commercial product Ma2504.[ ...]

During planned studies, the reactor of the fourth power unit, loaded with 180 tons of radioactive fuel, lost control, which led to an explosion and the release of about 50 tons of fuel into the atmosphere (V.A. Radkevich, 1997). It evaporated and formed a huge atmospheric reservoir of long-lived radionuclides. About 70 more tons of fuel were thrown out of the reactor from the peripheral sections of the core by the side beams of the explosion. In addition to fuel, the explosion also threw out about 700 tons of radioactive reactor graphite. Approximately 50 tons of nuclear fuel and 800 tons of graphite remained in the destroyed reactor. Due to the high temperature in it, graphite burned out in the following days and thereby contributed to an increase in the amount of radioactive fallout. Let us note for comparison that the total mass of radioactive substances that were formed as a result of the bomb explosion over Hiroshima was only 4.5 tons. At the same time, 600 times more long-lived and therefore especially dangerous radionuclides entered the biosphere than after the indicated nuclear explosion. ..]

However, this situation is very different from the so-called distant or global fallout, which is characterized by the gradual fall of radioactive particles from very high altitudes (about 10-12 km), where they circulated around the globe for 10-14 days. It was expected that the particles would fall over many months or even years, and before reaching the ground, the doses of radiation would be very small compared to the level of natural background radiation, equal to approximately 80-100 mrad / year.[ ...]

It can also be seen from the data presented that in July there was a very sharp drop in the phosphorus content in the sediment of the water extract from the sand in vessels both with plants and without plants, and the enrichment of the sand with rhizospheric microorganisms did not give a noticeable increase in the radioactivity of the sediment in this case. ...]

In the 50-60s, when as a result of the rapid development of technology it turned out that the entire biosphere of the Earth is under the influence of radioactive fallout, pesticides, industrial waste and other pollutants that threaten human health, the economy and the normal functioning of the biosphere, the concept of "environmental protection" arose. ".[ ...]

Throughout the time after the disaster, attempts are being made to restore the features of the spread and fallout of radioactive fallout, based on specific hydrometeorological conditions on each subsequent day, the release of fuel particles, aerosol particles and radioactive gases from the destroyed reactor (for example, Israel, 1990; Borzilov, 1991, review see: Exposure levels..., 2000) and fallout reconstruction based on the remaining radionuclides.[ ...]

These values ​​can be verified for the northern region, given that the ratio of rainfall in the two regions is 1.42 according to Levanne's results. Dose from mixed exposure to radioactive fallout and background radiation in northern Alberta during 1960-1961. was approximately 142±20 mrad/year.[ ...]

Signs of acute exposure develop within a few hours to a few weeks after exposure. Only those radioactive fallouts that fall in the vicinity of a nuclear weapon explosion can cause such signs (Cronkite, Bond a. Dunham, 1056; National Academy od Sciences, 1956b; US Department of the Army, 1957).[ ...]

One of the most important characteristics radionuclides is the half-life - the time required for the decay of 50% of the radioactive atoms present. The so-called short-lived isotopes, which have a very short half-life, are biologically less dangerous, since they are not able to accumulate in the biosphere. On the contrary, radionuclides with a long half-life can accumulate in the tissues of living organisms or pollute the natural environment in the form of radioactive fallout and aerosols. The characteristics of some radionuclides are given in Table. 37.[ ...]

The accident at the Chernobyl nuclear power plant in 1986 in its own way global implications is the largest environmental disaster in human history. A significant part of the European territory of the CIS with an area of ​​more than 100 thousand km2 was contaminated with artificial radionuclides. The radioactive fallout included about 30 radionuclides with a half-life of 11 hours (krypton-85) to 24100 (plutonium-239).[ ...]

Wesley's conclusion is probably correct that the nature of the geographical distribution of birth defects depends not only on local differences in drugs, food, or radioactive fallout, but is also associated with an increase in the number of defects when moving towards the poles of the level of natural background radiation. In addition, the northern industrialized countries will be significantly affected by radiation from other natural sources, such as the decay products of uranium and thorium released from rock or airborne products of combustion hard coal.[ ...]

Low-level background radiation causes mainly somatic rather than genetic damage, which is confirmed by the results of a study of the effect of radioactive fallout on mortality due to infectious diseases. The increase in mortality is due to a decrease in the body's ability to recognize and destroy viruses and bacteria. As you know, this effect is accompanied by damage to bone marrow cells and white blood cells.[ ...]

Radiation monitoring is carried out by EGASKRO (Unified State automated system control of the radiation situation on the territory of the Russian Federation) to determine the levels of radioactivity of environmental elements (water, air, soil, vegetation), ionizing radiation, the amount and composition of radioactive fallout.[ ...]

In 1960, the average concentration of 137Sv in milk in Canada was 55 pCi/l. This corresponds to an average dose of about 10-20 mrad/year received by mothers of children born in 1961 from all sources of radioactive fallout. These values ​​fall within the 5-40 mrad/yr range found in southern and northern Alberta, and are consistent with both the lower US south of 32 pCi/L and the much higher 150 pCi/L. for Norway, which is north of Alberta.[ ...]

The same regularity was observed in the experiment, where all the labeled phosphorus was in the yeast (see Fig. 5). The introduction of rhizospheric microorganisms together with yeast in this experiment very sharply reduced the radioactivity of the sediment of the aqueous extract, and this phenomenon was observed most sharply in vessels without plants. The number of microorganisms in different options This experience is inversely related to the amount of radioactive phosphorus bound by sediment.[ ...]

The sediment obtained by centrifugation of an aqueous extract consists of microorganism cells and silty mineral and organic particles. About specific gravity of microorganisms in the binding of phosphorus by the sediment can be judged by the increase in P32 in the sediment from vessels artificially enriched with rhizospheric microorganisms. The radioactivity of the sediment from pure uncalcined sand in June was 1729-1730 thousand imp/min, while the radioactivity of the sediment from sand enriched with microorganisms averaged 3559 thousand imp/min per 1 vessel (see Fig. 2B and 3B).[ ...]

Extremely high efficiency oxidative processes initiated by weak radiation can explain the statistics on the death of embryos, infants and premature birth, about leukemia, etc., which is associated with low-level radioactive fallout and the operation of nuclear equipment (at a dose of not more than 10-100 mrad, which is much lower than modern acceptable level 500 mrad). This also explains the fact that the overall mortality rate of adults and newborns due to all the causes mentioned is significantly more affected by exposure for days and weeks than exposure during a short flash (for example, X-rays used in diagnostics).[ ...]

As a result, it becomes clear that if a real effect of natural radiation on morbidity can be noted at a sensitivity of 0.1-1.0%/mrad, typical for membrane damage at low radiation levels, then there is a similar effect from radioactive fallout from distant nuclear tests. This effect is most easily detected by somatic damage to cell membranes and due to a violation of the developmental processes of the child in the infancy, leading to birth defects.[ ...]

During ground explosions, a huge amount of solid particles rises into the air, including due to melting and evaporation. In the process of cooling, the particles become larger and about 50% settles behind the ground within 2-3 days. The remaining half of the particles settle on the ground later. Enough has already been said about the biological effect of radioactive contamination. It is essential that during a nuclear war the entire northern hemisphere will be exposed to radioactive fallout, and to a greater extent from explosions in the atmosphere than from ground explosions. As a result of such a distribution of radioactivity, radionuclides will penetrate into all links of the food chain of ecosystems of the northern hemisphere and reach a person, even if he was not directly exposed to radiation during a nuclear explosion. The continuous movement of radionuclides in the soil for a number of years will not make it possible to obtain a crop of plants that do not contain radioactive contamination. The northern hemisphere serves as the main granary, producing the main amount of agricultural products, and for help from outside southern hemisphere in this sense, one cannot count.[ ...]

Over the past 10 years, various aspects of the problem of atmospheric air pollution continue to attract attention. The main reasons for this interest are the tragic cases of atmospheric pollution, accompanied by fatal outcomes (catastrophes in Donor in 1948 and in London in 1952); the Los Angeles air pollution problem, unique but of general importance; danger of radioactive fallout; familiarization of the population with the effect of chronic action of atmospheric pollution; the development of industry and the growth of cities, leading to an increase in emissions into the atmosphere; new types of contaminants or detection is already good known species but in new places; widespread restructuring of polluted urban areas; times of material well-being, when cleanliness is envisaged as one of the conditions of a normal life; development of science and technology and improvement of ¡control equipment.[ ...]

And here is a typical interview on the same topic from the early 90s. Weekly newspaper of Chelyabinsk "Voice" No. 26 of July 10-17, 1992 "State policy: silence is golden. As a last resort - strontium-90” Journalist V. Sitnikova talks with the head. Department of Radiation Hygiene of the Regional Sanitary and Epidemiological Station E.M. Kravtsova. The reason for the meeting was a letter from A.G. Vorobyov, in which he touches upon the problems associated with the accident in 1957. “At that time I lived and worked in the village of Pyankovo, Larinsky village council. A strip of radioactive fallout divided the village into two equal parts. More than 500 hectares of pastures, hayfields, evicted villages were transferred to the use of the collective farm. Sverdlov. From the very first days after the departure of the special detachment for the disinfection of the territory, our team cultivated these lands for 20 years: they sowed, harvested crops, grazed livestock, and prepared forage. By 1973, the villagers had dispersed all over the country without receiving any compensation. Many of them have already died before reaching the age of 50. The rest are sick...”.[ ...]

Like a class society, the risk society is polarized, but it is polarization in reverse. In a class society, wealth and benefits are concentrated at the top of the social pyramid, and in a risk society - at the bottom, at its base. It can be said that poverty seems to attract risk. This also applies to environmental risks - companies and firms from developed countries carry out harmful production to the poor countries of Asia, Africa and South America. It would seem that the wealthy classes can "pay off" the environmental risk. However, the so-called “boomerang effect” operates in the risk society. There are no state borders or class distinctions for ecological catastrophes. Fallout from nuclear weapons testing or accidents at nuclear power plants, acid rain, climate change affect the rich and the poor alike. As for the “export of hazardous industries”, the “boomerang effect” is also manifested here. Crops grown in poor countries - coffee, cocoa, fruits - are increasingly being contaminated (both by pesticides and by toxicants thrown out of the pipes of chemical plants). It is clear that the importation of such products into Western countries is accompanied by an increase in risk for their populations. Thus, sooner or later, those who initially benefited from the development of dangerous technologies are also at risk. The worst-case scenario for the future of mankind, as is known, includes a nuclear missile war in which there will be no winners. Pessimistic options for the evolution of the risk society are to some extent similar to this scenario, since after global environmental catastrophes there will be neither "environmental criminals" nor their victims left on Earth.

fallout

Radioactive fallout - radioactive aerosols deposited from the atmosphere arising from nuclear weapons testing. Radioactive fallout is divided into: local, tropospheric and stratospheric.

Local R. about. are large, predominantly melted particles that fall out under the action of gravity near the explosion site. Their main sanitary significance is defined as sources of gamma radiation. Tropospheric radioactive fallout - radioactive particles of micron and submicron size that enter the troposphere during a nuclear explosion. For 2-6 weeks, they are carried by air currents around the globe, gradually settling on the earth's surface. They contain predominantly short-lived isotopes, of which radioactive iodine poses the greatest sanitary hazard. A decisive role in the purification of the troposphere is played by precipitation (especially drizzling rain). Stratospheric (or global) radioactive fallout - radioactive particles injected during a nuclear explosion into the upper atmosphere (stratosphere) and slowly deposited on the ground. Their residence time in the stratosphere ranges from 2 to 5 years. They contain predominantly long-lived isotopes (strontium-90, cesium-137, cerium-144, etc.). The density of global radioactive fallout is uneven at different latitudes. The maximum fallout after the cessation in 1963 of mass nuclear weapons tests took place between 20-60°N. sh. Due to the peculiarity of the transfer of air masses, there are seasonal fluctuations in the density of precipitation with a maximum in spring - early summer. Further migration of radioactive isotopes that have fallen to the surface of the earth along the biological chain is determined by their biological availability. Unlike local fallout, which consists mainly of large melted insoluble particles, stratospheric radioactive fallout, consisting of fine fractions, has a high degree (strontium-90, cesium-137) of biological availability. The solubility of these particles can reach 100%. In the first years after the testing of nuclear weapons, ground vegetation was polluted everywhere through the direct precipitation of radioactive waste. to the surface of plants. Subsequently, their migration into the plant by the root route from the soil becomes increasingly important. highest density radioactive fallout dates back to 1963, as a result of which the maximum exposure doses to the population due to stratospheric precipitation occurred in 1963-1964. However, even during this period they did not exceed the dose limit set for the population. Due to a decrease in the density of radioactive fallout and radioactive decay, the supply of radioactive isotopes is decreasing every year. Accordingly, the absolute values ​​of the radiation dose to people are reduced. For example, radiation doses bone tissue in adult residents of Moscow in 1968, due to incorporated strontium-90, they were 2.6 mrad / year, i.e. less than 10% of the dose limit.

The absence of a real health hazard from such doses eliminates the need for any preventive or remedial measures.

However, monitoring of the radiation situation caused by global fallouts on the territory of Russia is carried out continuously in order to study the relevant patterns. The objects of observation are atmospheric air, soil, open water bodies, vegetation, food products. Constant monitoring of the content of radioactive substances in the body of various age groups population and population dose due to global radioactive fallout.

Fallout is fallout from a radioactive cloud resulting from the explosion of a nuclear device.

Distinguish radioactive fallout local, delayed and global. R. o. local have particles with a size of the order of tens of microns or more; fall out during ground explosions for several tens of hours and spread in the direction of the wind to 500-550 km from the center of the explosion. Delayed (semi-global, tropospheric, continental) R. o. have particles with a size of the order of 1-5 microns; fall within a few weeks after the explosion (usually up to 5 months) and spread in a latitudinal direction. Global, stratospheric R. about. have particles smaller than 1 micron; fall over a number of years, usually more intensively in the spring.

The nature of the formation and loss of R. o. depends on the nature of the explosion (ground, air, surface), TNT equivalent, nuclear device, the nature of the soil in the area of ​​the explosion and meteorological factors.

During a ground explosion of a nuclear device with a TNT equivalent of about 1 Mt, about 20,000 units of evaporated soil are added to the ordinary substances that make up the fireball (fission products, charge shell and other parts heated to a temperature of several million degrees). In addition, the air currents accompanying the explosion raise a significant amount of dust and other solid particles that make up the "leg" of the specific "mushroom" of a nuclear explosion.

Radioactive contamination as a result of such an explosion covers an area of ​​about 28 thousand km 2 an hour after it. Local precipitation makes up approximately 90% of the entire mass of soil raised during a ground explosion.

The finely dispersed part of the soil raised into the air passes into the stratosphere, subsequently forming the basis for the formation of global radioactive fallout. During air explosions (the fireball does not touch the surface of the earth), the formation of local precipitation does not occur, and the bulk of the radioactive fragments raised into the stratosphere subsequently forms global precipitation.

Thus, as a result of explosions of nuclear devices, a large number of various radioactive isotopes that are carried by air currents, polluting the areas farthest from the explosion site.

For many years, Sr 90 , Cs 137 and other radioactive isotopes produced by the explosion will be transported air currents. The highest density of radioactive contamination is created by local radioactive lakes, the isotopic composition of which is represented mainly by short-lived radioactive fragments, primarily radioactive J 131 .

The decline in radioactivity in the first period after a nuclear explosion (up to 100 days) obeys the law t -1.2. The isotopic composition of delayed R. o. less diverse, however, J 131 also plays a rather significant role in them. As part of global fallout, radioactivity is represented by long-lived fragments - Sr 90 , Cs 137 , Ce 144 , Pr 144 , Pm 147 and some others, however, Sr 90 and Cs 137 are mainly biologically significant.

Falling onto the surface of the soil and plants, radioactive fallout enters into cycles of biological processes continuously taking place on Earth, migrating in a complex way along various links in the ecological chain (see Ecology, radiation). A study of the mechanism of penetration of Sr 90, a component of global R. o., showed that up to 80% of it is concentrated in the surface layer of uncultivated land 5 cm thick. In arable land, it is distributed over the entire depth of plowing. With the continuing loss of R. o. The amount of Sr 90 that enters the human diet depends more on direct contamination of the leaves, inflorescences and lower parts of perennial plants than on its uptake by roots from the soil. If the rate of radioactive fallout decreases, then uptake by the roots begins to dominate.

A number of radioactive substances formed during explosions of nuclear devices enter the human body and accumulate in it. Of particular biological importance is Sr 90 , which has a 28-year half-life and accumulates in the human skeleton. The main accumulation of strontium occurs in the fast-growing parts of the bone - the epiphyses, which turn into a kind of strontium "depot", from where constant irradiation of nearby areas of the bone and bone marrow is carried out (see Radiation toxicology).

Due to the biological significance of R. o. in the USSR and a number of other countries, a system has been developed and is being implemented to control the levels of radioactive fallout, migration and entry into the human body of the most important radioactive fragments of nuclear fission.

As a result of the nuclear test ban treaty in three environments, the number of R. o. decreased significantly and continues to decline. See also Radiation Hygiene.

Waste from cement plants - dust from cold chambers; fine powder, prone to cementation. Chemical composition it varies significantly depending on the type of cement produced. The neutralizing ability of cement dust ranges from 63 to 80% (in terms of calcium carbonate, sometimes exceeds 90%, humidity is not more than 2%. Calcium in it is in various compounds: carbonic salts, oxides, silicates, etc.). Magnesium is present in a small amount, a lot of sulfur compounds, incl. plaster. The waste of cement plants has a good particle size distribution - often finer than 0.25 mm 90-97%.
Pneumatic machines are used for application. Cement dust is a good lime fertilizer. It is introduced into the soil 1.5-2 weeks before sowing, so that the sulfur compounds present in it have time to oxidize into sulfate.
Belite sludge is a fine-grained mass, which is a waste product of the aluminum industry. The main component of the waste is the mineral belite and a small amount of undecomposed feline. The material contains from 10 to 15% moisture. Calcium is found mainly in the form of silicic compounds. The chemical composition of belite sludge depends on technological conditions production and fluctuates within the following limits (%): CaO - 50-58, MgO - 0.2-2.2, SiO2 - 24-31%, ferrous iron - 2-5.5%. It has a good particle size distribution and can be applied without preparation. Due to the high neutralizing ability of belite sludge (85-99% CaCO3), it is advisable to use it as a calcareous material for root liming of soils. In the composition of belite sludge, an increased content of cadmium, lead and strontium was noted. However, with the frequency of liming with this material once every 5 years and doses not exceeding 5 t/ha, no dangerous contamination of soils with these elements is observed.
It is expedient to introduce belite sludge with pneumatic spreaders, followed by plowing the soil. For environmentally friendly safe use ameliorant, the dose of its application should be limited on sandy and sandy soils to 5 t/ha, on more than heavy soils it is possible to apply up to 8 t/ha of the ameliorant. It is necessary to ensure its introduction into the soil no later than two weeks before sowing crops, and ensure its immediate incorporation into the soil.