Biogeochemical provinces

Using these approaches, biosphere mapping is accomplished over such units as region, sub-region and biogeochemical province. 

Biogeochemical provinces are the third order units of biosphere. These are areas whose organisms exhibit permanent characteristic biological reactions to excesses or deficiencies of essential nutrients in the region s biogeochemical food webs. The typical forms of these reactions are endemic diseases. There are two types of biogeochemical provinces ... 

The first step in subdividing the biogeochemical provinces is to establish the existence of a correlation between the frequency of the endemic diseases and excessive or deficient content of essential elements in their respective food webs. However, we should also understand the biochemical and physiological mechanisms that drive the given correlation. Four additional notions should be applied ... 

System 241. feeding of domestic animals, forage (XIV, XV) balanced essential trace element daily intake (XVI) domestic animals (XVII). The additions of requirement trace elements should be applied for forage in various biogeochemical provinces. 

Field monitoring and experimental simulation allow the researcher to study the variability of different links of biogeochemical food webs and to carry out the biogeochemical mapping of biosphere in accordance with above-mentioned classification regions of biosphere, sub-regions of biosphere and biogeochemical provinces. 

Chemical elements Distribution of sub-regions and biogeochemical provinces Content of elements in biogeochemical food webs Biological reactions of organisms and endemic diseases... 

Azonal sub-regions and biogeochemical provinces, which features differ from the typical features of regions of biosphere ... 

F deficit Biogeochemical provinces in different regions of biosphere Content of F in natural waters < 0.5-0.7 ppm Reducing content of F in tooth enamel. Endemic tooth carious in humans and animals... 

Mn deficit Biogeochemical provinces in different regions of biosphere Lowering content of Mn in soils and plant species Reducing Mn content in bones. Decreasing activity of phosphatase, phosphorilase, and isocitric dehydrogenase... 

In 1938 A. Vinogradov published the book Biogeochemical provinces and human endemic diseases . He has analyzed the relationships of organisms and populations with geochemical structure of the biosphere. This book initiated the... 

According to the specific characteristics of North Eurasian biogeochemical provinces, the alterations of the biogeochemical food webs were studied for I (endemic goiter), Si (the Urov disease), B (endemic enteritis), Se (endemic myopathia), and Mo (endemic gout). On a basis of these results, the recommendations have been produced for correction of daily intake of essential elements. 

The antagonistic influence on cancer development due to organic carcinogens may be induced by chemical species of Se, As, Al, Co, Cu, Zn and Mo. We should note that the antagonistic effects of the latter metals depend strongly on their concentrations (see above on limit concentrations). Similar interactions are characteristic for the combinations of metals in biogeochemical food webs of various biogeochemical provinces. 

Cancer Risk Endpoints in Different Biogeochemical Provinces... 

The influence of various trace elements has been studied during the 1980s—1990s in the Forest Steppe and Mountain regions of the biosphere, in Ukraine. Three natural biogeochemical provinces, Carpathian, Pre-Carpathian and Forest Steppe, have been monitored for the migration of trace elements in food webs and human cancer distribution (Table 3). 

In the Pre-Carpathian biogeochemical province with prevalent Eutric Podsolu-visols, enriched in lead and barium and depleted in chromium and vanadium, the predominant diseases are mieloleukemia, chronic lymphatic leukemia, hemorrhagic vasculitis, hypoanemia with a relatively low number of sharp leukemia, lung and stomach cancer. 

In Forest Steppe biogeochemical province with Eutric Phaerozems and Distric Chernozems, enriched in all trace metals, such illnesses as lung and stomach cancer, tumor of cerebrum and spinal cord, and nephritis are predominant, whereas the Addison-Bearmer anemia, progressive myopia and glaucoma are relatively seldom. 

Figure 2. Bio geochemical mapping of the Chuvash administration region, Russia. Bio-geochemical regions 1—Pre-Kubnozivilsk, 2—Pre-Sura, 3—Pre-Volga, 4—Biogeochemical provinces—(a) silicon (b) fluorine, and(c) nitrate, Soils 5—Podzoluvisols, 6—Phaerozems, 7—Chernozems, 8—Arenosols.

Let us consider in brief the nitrate biogeochemical provinces, where a significant growth of cancer incidents has been observed. It is known that the absorption of nitrate and nitrite from water in the intestinal tract is 2 times as much as from food products. This means that the accumulation of nitrate in drinking water sources should be of special concern during consideration of food webs in any relevant biogeochemical province. 

As an example, we will consider the formation of nitrate biogeochemical provinces in the Desert region of biosphere in Zerafshan river watershed that occupies most of the Samarkand administrative region of Uzbekistan. This is an agricultural area with irrigation production of cotton and some other crops like cereals, vegetables and fruits. The natural biogeochemical provinces are characterized by iodine, copper, and zinc deficiency and lithium excess. 

We can see that the concentrations of both nitrate and nitrite in drinking water and vegetables are excessive. The accumulation of nitrate in food web of this biogeochemical province was accompanied with a high content of residual pesticides in soils of agroecosystems (Table 10). 

Table 10. The residual content of persistent organochorine compounds in soils of nitrate biogeochemical province of the Desert region of biosphere, Uzbekistan, ppb.

HUMAN HEALTH ENDPOINTS IN TECHNOGENIC AND AGROGENIC BIOGEOCHEMICAL PROVINCES... 

Box 3. Statistical assessment of morbidity in technogenic and agrogenic biogeochemical provinces of North Eurasia (after Evstafyeva et al., 1999)... 

---