Water Content of Aluminum, Dialysis Dementia, and Osteomalacia

Abstract

In the presence of normal renal function, a high concentration of aluminum in drinking water has been implicated as a factor in the etiology of a neurological syndrome in one specific geographical area. The role of aluminum as a toxic agent in other neurological disorders, where renal function is normal, is controversial.Aluminum is absorbed from the gastrointestinal tract and is normally excreted by the kidneys in the urine. In patients with chronic renal failure, aluminum appears to be of proven toxicological importance. In these patients the accumulation of aluminum in tissues causes an encephalopathy (dialysis encephalopathy or dialysis dementia), a specific form of metabolic bone disease (osteomalacic dialysis osteodystrophy), and an anemia and also plays an etiological role in some of the other complications associated with end-stage chronic renal disease. A failure in the normal renal excretory mechanism accounts for the tissue accumulation in chronic renal failure. The majority of chronic renal failure patients who develop aluminum toxicity are on long-term treatment with either hemo-or peritoneal dialysis; some patients develop toxicity who are only on treatment with aluminum-containing phosphate-binding agents.Aluminum in the dialysate appears to be the major source of the metal in chronic renal failure patients who develop aluminum toxicity. The aluminum content of the dialysate depends primarily on the content of the water with which it is prepared; there may be some contribution from the chemicals used in the concentrate which is added to the water. Some domestic tap-water supplies contain aluminum in high concentration, either naturally or because aluminum has been added as a flocculant in the purification process. Acid rain markedly increases the "natural" aluminum content of water.The driving force for aluminum transfer during dialysis seems to be the effective concentration gradient between the dialysate aluminum and the free diffusible serum aluminum fraction. The transfer of aluminum from the dialysate across the dialyzing membrane appears to occur despite low concentrations of the metal in the dialysate. The species of aluminum in tap water and dialysate may significantly affect the dialysability of aluminum into the blood compartment and its subsequent deposition in tissues. The major portion, if not all, of aluminum in blood is tightly bound to serum proteins and an as yet unidentified lower molecular weight species.Aluminum is the third most abundant element in the earth's crust and is the most abundant metal. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago. Aluminum cooking utensils were being introduced at that time, and these together with the aluminum present in city drinkingwater and a variety of medicines were considered to represent a potential health hazard (1). In the intervening years, although the subject has been controversial, aluminum was not, until recently, recognized as a toxic metal. Aluminum was dismissed as a toxic metal in...

Human health risk associated with the management of phosphorus in freshwaters using lanthanum and aluminium

“…Conversely, a concomitant intake of aluminium with an increase of 10 mg/day in silica intake via drinking water was associated with a reduced risk of dementia (Rondeau et al 2009). Until the early 1980s aluminium in the dialysate appeared to be the major source of the metal in chronic renal failure patients who developed aluminium toxicity (Wills and Savory, 1985). As at that time adequate water purification systems were not available in all dialysis units, the aluminium concentration of the dialysate depended primarily on the aluminium concentration of the water with which it was prepared; whether further enriched with aluminium-contaminated chemicals or not in the concentrates which are added to the water to prepare the final dialysis fluids (D'Haese et al 1990).…”