From Big Medical Encyclopedia

BIOGEOCHEMICAL DIVISION INTO DISTRICTS — division of the territory into regions and subregions of the biosphere (biogeochemical zones and provinces) differing on the nature of interaction of organisms and geochemical environmental factors.

The B. river matters, in particular, for studying and the organization of fight against local diseases. At B. rubles of the territory allocate zones which are characterized by unity of soil-forming processes, climatic factors, biogenic migration of chemical elements and biological responses of organisms on geochemical and physical. factors of the environment.

Fig. 1. Biogeochemical food chain.
Fig. 2. Dependence of regulatory processes in an organism of animals (A)) from the content of chemical elements in their diet (B): 1 — insufficient amount of chemical elements; 2 — normal quantity; 3 — excess quantity.

One of important criteria of B. of river is definition in the environment (soils, waters), and also in sterns or daily diets of top and bottom threshold concentration of chemical elements, above or below which regulatory mechanisms of processes of a metabolism in vegetable and animal organisms (fig. 1 and 2) can be broken.

Concentration of chemical elements within which regulatory systems normally function and the optimum level of a metabolism is supported, are accepted as the requirements corresponding to possible changes in macro - and microelements under various conditions. The big complex of the criteria considered at B. by river covers various parts biospheres (see), as whole ecological system. At the same time forms of relationship of organisms and Wednesday at the different levels of the organization of life in the biosphere (the biogeochemical zones called regions of the biosphere, the subregions corresponding to biogeochemical provinces, biocenoses, populations, organisms, suborganismic levels), and also biological and biochemical mechanisms of adaptation of organisms to conditions of the changing links of a biogeochemical food chain in connection with chemical mosaicity of the biosphere are studied. A basis of development of the system of B. of river was the evolutionary unity of life and the geochemical environment in the biosphere.

Biogeochemical zones (regions of the biosphere) divide into subregions — zone biogeochemical provinces in which signs of zones are combined (on concentration, ratios of chemical elements and biological responses), and azonal which signs do not correspond to the characteristic of zones (they form at dispersion of the chemical elements concentrated in ores, in the conditions of drainless zasoleniye, in regions of a volcanism etc.).

The description of separate biogeochemical zones and provinces is included below.

Taiga and forest nonchernozem zone it is characterized by the insufficient content of calcium, phosphorus, potassium, cobalt (in 73% of all studied samples of soils), copper (70%), iodine (80%), molybdenum (55%), boron (50%), zinc (49%), the sufficient content of manganese (72%) and relative excess of strontium (15%), especially in floodplains of the rivers. Soils are acid sod-podzolic, podsolic, sandy, sandy, peat and marsh, sands.

Biogeochemical characteristic forest-steppe, steppe chernozem zones (including gray forest soils) is defined by the sufficient level of content of calcium, cobalt (in 96 and 77% of cases, respectively for gray forest and chernozem soils), copper (72 and 76%), manganese (75 and 71%), and sometimes a lack of mobile manganese; balance of iodine, zinc and molybdenum with other elements; sometimes lack of potassium, seldom boron, often phosphorus. In this zone the biological responses characteristic of other zones usually do not meet. The local enlargement of the thyroid gland and a craw occur in some cases at the persons living on gray forest soils is frequent in floodplains of the rivers and on lixivious chernozems.

Sukhostepny, desert and semidesertic zones are characterized by the increased content of sulfates, boron (88%), zinc (76%), often strontium (47%), rather high — molybdenum (more than 40%), rather low — iodine (80%), copper (apprx. 40%) and sometimes cobalt (52%); in some desert areas — excess of nitrates (the endemia of a methemoglobinemia is possible).

In certain cases zinc is a little acquired by plants that causes emergence of provinces of zinc insufficiency. Soils — neutral and alkaline — brown, desert and steppe, light brown, solonetzic, saline, solonetzic soils, sandy, meadow-steppe.

Mountain zones at various heights have various biogeochemical characteristic. Biological responses are various and are defined by non-constant concentration and a changeable ratio of many chemical elements, a lack of iodine (95%), sometimes a lack of cobalt (31%), copper (28%), zinc (24%), excess in certain cases of molybdenum, cobalt, copper, lead, zinc, strontium and other elements. Soils — mountain, various.

In to nonchernozem zone 73% of all studied samples of soils contain rather low amount of cobalt therefore disturbances of exchange of cobalt both local hypo - and avitaminosis of B are characteristic of this zone 12 . Contain enough cobalt therefore in it diseases of «cobalt insufficiency» practically do not meet in a chernozem zone of 77% of all studied samples of soils.

In provinces with a lack of copper of pasturable herbs, and also of hay (in 30% of tests of plants concentration of copper is lower 3*10^-4 than % — to 7,2*10^-5%), of an organism of animals the copper content is lowered that is the reason of weakening of synthesis of the oxidizing enzymes containing copper and iron. At animals the hemosiderosis, local anemias are observed (sheep, cattle, are more rare other animal species).

It is known that at a lack of iodine of a nonchernozem zone (75% of tests of pasturable plants contain iodine less than 8-10-6% — to 2 * 10-7%) function of a thyroid gland is broken, there are its local increase and a local craw. In nature there is no invariable correlation between a lack of iodine and spread of a craw (see. Craw local ). It is established that especially bright displays of a local craw are observed in provinces with a simultaneous lack of iodine and cobalt, napr, in the Petrovsky region of the Yaroslavl region. In Altai Krai correlation of spread of a craw with a lack of iodine, copper and cobalt was noted.

At a simultaneous lack of copper and cobalt (is more often on peat soils) at animals synthesis of vitamin B is weakened 12 also the level of oxidizing processes is lowered. In these conditions there are local anemias, hypo - and avitaminosis of B 12 , the complicated lack of copper (sheep, cattle).

At a lack of calcium and relative excess of strontium there is an endemia of an urovsky disease at the person and animals (see Kashin — Beck a disease). The relation in sterns and foodstuff of calcium to strontium is equal 140, in control areas here — 14.

In to sukhostepny, desert and semidesertic zone provinces with a relative lack of copper and a lot of boron are widespread. «Copper insufficiency» at animals is shown both at primary (alimentary) lack of copper, and at excess of molybdenum and sulfates. In soils of the provinces of Dagestan the relation copper: molybdenum: sulfates are made by 1: 0,58: 327 (till 1170); in the provinces of Uzbekistan — 1: 0,27: 890, in control areas — 1: 0,1:.... Under such geochemical conditions exchange of copper at different types of animals (sheep, cattle, buffalo s) is broken, there is a local ataxy.

Excess of boron in diets leads to emergence of local enterit, sometimes pneumonia: in the Western Kazakhstan both at the person, and at animals (sheep, camels), in Kulunda Steppe and in steppes of the Volga region — at sheep.

In mountain zones the provinces poor in iodine in which the local craw is widespread meet; in the provinces poor in cobalt, at animals it is observed hypo - and avitaminosis of B 12  ; at a lack of copper animals have local anemias; at a lack of calcium at animals mineral metabolism in a bone tissue is broken.

Also many azonal biogeochemical provinces are known. Treat them: the provinces rich with cobalt, under influence to-rogo at animals synthesis of vitamin B is strengthened 12 , and in certain cases, on the contrary, it is slowed a little down; the provinces poor in iodine and manganese where the endemia of a craw at the person and animals amplifies; the provinces rich with lead in which at the person nervous diseases — cephalalgias are observed, mialgiya, etc.; the provinces rich with molybdenum, under influence to-rogo in an organism synthesis of enzyme of a xanthineoxidase and education uric to - you amplifies (the person at the same time can have a local molybdenic gout; in Armenia, in Ankavansky district, at 31% of adult population some symptoms of gout, and are found in animals — molybdenic toxicosis); the provinces rich with strontium and calcium owing to what at animals fragility of bones, at the person perhaps local disease is observed chondrodystrophia (see), and also emergence of a special form of the rickets steady against effect of vitamin D; in the provinces enriched with selenium at animals deformation of hoofs and baldness is observed; in the provinces enriched with uranium there is a concoction of uranium tissues of animals, many plants concentrators — are characterized by morphological variability. Provinces a lot of fluorine in which local disturbances of ossification, deformation of bones, narrowing of a cavity of the marrowy channel, a local fluorosis (animals, the person) are observed meet; the provinces enriched with copper where at sheep local cirrhosis, anemia, jaundice is observed; the provinces rich with nickel, magnesium, strontium poor in cobalt, manganese in which mineral metabolism in bones of animals is broken and there is local dystrophy of a bone tissue; the provinces rich with nickel where the relation of nickel to copper is equal in vegetable sterns to 1: 0,6, and nickel is laid at animals in epithermal tissues that can cause a local complication of diseases of these fabrics. In the provinces poor in fluorine, local caries of teeth is widespread among animals and the person (see. Caries of tooth ), and in poor in manganese meets local perozis (birds are ill more often).

The B. ruble allows to characterize biogeochemical zones and provinces various reactions of organisms to the different maintenance of chemical elements in the environment. These reactions of organisms show the natural variability of a metabolism at animals and the person caused by various, but certain geochemical conditions of the environment. In extreme conditions of a sharp shortcoming or surplus of chemical elements in the environment intra population differentiation of organisms amplifies and natural selection escalates. The B. river serves one of bases of clarification of the general patterns of development and the organization of ecological systems of the biosphere.

See also Biogeography , Biogeochemical provinces , Biogeochemistry , Biogeocenosis , Geography medical , Nozogeografiya , geographical zoning .

Bibliography: Vinogradov A. P. Biogeochemical provinces, Works of the yubi-lane. ses. Academy of Sciences of the USSR, it is devoted, to century since the birth of V. V. Dokuchayev, page 59, M. — L., 1949; Kovalsky V. V. Geochemical ecology, M., 1974; it, the Variability of a metabolism at animals caused by natural volumetric factors of the environment, Vestn, selskokhozyaystvo. sciences, No. 1, page 64, 1971; it, Regions of the biosphere — an oonov of biogeokhimiche-sky division into districts, in book: The biosphere and its resources, under the editorship of V. A. Kovda, page 90, M., 1971.

V. V. Kovalsky.