Cancer Diseases in Middle Volga Silicon Sub-Region of the Biosphere

The deficit of I, Co, Mn, and Zn, moderate excess of Si and disturbed ratios of trace metals to I and Si are characteristic features of the biogeochemical food web of this Pre-Volga sub-region of biosphere. Most natural water sources have a decreased content of flour. These peculiarities of biogeochemical food web favor the occurrence of tooth decay (caries) and endemic goiter. 

Hardness nieq/L Per cent from monitored drinking water sources Rank of cancer illnesses 

In this biogeochemical sub-region the rate of carcinogenecisis was also correlated with the drinking water hardness. The water hardness is connected with the content of Ca, Mg and Fe compounds (Table 4). 

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