Well water characteristics and the Balkan nephropathy.

A total of 366 inhabitants of a village affected by Balkan nephropathy (BN) have been followed over 12 years. It was shown that depth of the well to the water level, height of the water column, electroconductivity, and NO3 content of the water were not associated with BN. The risk of developing the disease was significantly higher if a well was at a lower altitude and contained a higher concentration of SiO2. Low altitude might have been expected to correlate with the BN frequency; as for silica, however, there are sound indications that it could just be a correlate of a cause rather than a direct determinant of BN.