Acute epidemic aluminium osteomalacia secondary to water supply contamination.

When the aluminium content of the water supply to our Haemodialysis Unit rose from less than 0.5 mumol/l to 6 mumol/l over a two month period, we carried out bone biopsies and desferrioxamine infusion tests on twelve (12) patients who had been on haemodialysis for less than one year (mean 8 months) and had normal serum aluminium levels. The patients had no bone symptoms. Eight patients had positive aluminium bone stains. The aluminium osteomalacia group (n = 8) had a mean PTH of 1.4 ng/ml s.e. 0.3 whereas the non-ALO group had a mean PTH of 2.9 ng/ml s.e. 0.7. The difference in mean PTH is significant (p less than 0.05). There was no evidence of encephalopathy, fractures or microcytic anaemia in the ALO positive group. The aluminium contamination of the water supply occurred because of a change in the reservoir purification system from sand-filtration to alum.