Aluminium and fluoride in the water supply and their removal for haemodialysis.

Aluminium and fluoride in the water supply and their removal for haemodialysis have been investigated in the Trent Region, U.K., and wide variations noted. The efficiency of removal of these elements from the mains water supplying home haemodialysis units by different water treatment systems currently installed has been assessed and a follow-up study performed 8 months later. Some improvement in water treatment was noted, with the percentage of home dialysis units receiving waters within the proposed European Economic Community guidelines for aluminium rising from 61.7 to 72.1%. Removal of fluoride by the different treatment mechanisms is analogous to that for aluminium. A comparison of new and older water treatment systems has shown that there is a deterioration in performance with use. However, some cases of poor removal may be due to the installation of unsuitable equipment, or, more probably, due to a change in the waters used to supply the different homes. Thus, adequate maintenance of equipment and frequent sampling of both untreated and treated waters are required in order to maintain the provision of waters suitable for the preparation of dialysate.