Brackish water in the Arava Rift Valley in Southern Israel has a high sulphate and magnesium content. The inhabitants who drink this water have hypocalcaemia and hyperphosphataemia suggestive of parathyroid hypofunction. They also have a low urinary pH, massive urinary sulphate excretion, and a compensated metabolic acidosis. It is suggested that the low urinary pH may be one of the reasons for the high incidence of uric nephrolithiasis in the region.
INTRODUCllON
Brackish water is the only naturally occurring water source in the Arava Valley in Soufhern Israel. The region, a hot desert, extends from the Dead Sea to the Red Sea. The water contains high concentrations of sulphate: magnesium and calcium. Up to 20 litres a day of this water are drunk hy manual workers during the summer (mean maximum temperature 37Β°C and minimum 23Β°C). An intake of this magnitude results in a daily consumption of up to 6g of sulphate and of l-2g of magnesium and of calcium. A very high incidence of renal stone has been reported in the region (2). In this communication it is shown that the drinking of brackish water in the Arava is associated with a very acid urine of a high sulphate content, with a compensated metabolic acidosis, and with hypocalcaemia and hyperphosphataemia.
Methods
The study was carried out on healthy males aged 20 to 30. The subjects were agricultural workers from three Negev Kibbutzim: Grofit and Yotvatah, l Ordinarily, fk~~&zu&z does not deal with mtxlical articles. We thought however. that it would be of interest for otxr readers to consider what are appropriate standards for desalinated water. We wouki be pkasex3 to receive further articles in this area. Ed.