ALUMlNIUM IN DRINKING WATER AND ALZHEIMER'S SYNDROME - FINAL REPORT
Report No FR0376

D J Bowen, A M Gunn, R F Lacey and R F Itzhaki* * University of Manchester Institute of Science and Technology (UMIST), PO Box 88, Manchester M60 1QD

Mar 1993

SUMMARY

I BENEFITS

Research into the links between aluminium and Alzheimer's syndrome is being carried out by a number of organisations, and water suppliers need to be in a position where they can comment on the reported conclusions of such research, and assess the implications for themselves and their customers. Work funded by FWR was designed to increase the understanding of any possible link between the presence of aluminium in drinking water and the incidence of Alzheimer's syndrome

II OBJECTIVES

To attempt to clarify whether the presence of aluminium in drinking water is in any way a risk factor for Alzheimer's syndrome.

III REASONS

If aluminium was to be directly implicated in the incidence of Alzheimer's syndrome, which poses a significant health problem in the UK then an alternative coagulation process would be needed. The investment in new plant and process technology would be great, and would therefore need to have a sound scientific basis. Consequently, those responsible for setting standards for aluminium in drinking water, and for deciding the policy for its future use as a coagulant, need to have information on how much of an individual's total uptake of aluminium is provided by drinking water, and to what extent, if any, this influences the initiation or progression of Alzheimer's syndrome.

IV CONCLUSIONS

  1. It is still not possible to clarify the position of aluminium in relation to the initiation and progress of Alzheimer's syndrome since data continue to be produced which both implicate and dismiss a role for aluminium.

  2. If aluminium is found to be significant in the development of Alzheimer's syndrome then it now seems likely that its role will be secondary rather than primary in nature.

V RESUME

As the final report, this report brings together all the research undertaken so far by WRc and collaborators on aluminium and Alzheimer's syndrome, taking place under the project Toxicity and Health'.

Speciation studies have demonstrated that the chemical species of aluminium change during water treatment, forming a highly unstable, chemically reactive species expected to exhibit a high bioavailability. However, the results of bioavailability studies indicate that the uptake and hence bioavailability of aluminium from water is extremely low. In addition the uptake of aluminium from tea, known to be a rich source of aluminium, was also found to be low. Preliminary bioavailability studies on children's teeth have demonstrated a statistically significant difference between areas of high drinking water aluminium and areas of low drinking water aluminium.

A review of recent toxicological and medical data on aluminium's role in Alzheimer's syndrome identified no single study which resulted in a large shift of scientific opinion either way or the clarification of any uncertainty. However, scientific opinion does appear to be moving away from the single cause theory for Alzheimer's syndrome, suggesting that there may be several distinct but interrelated factors which could lead to its development. On the basis of data currently available, aluminium cannot be excluded as having some role to play in the development of Alzheimer's syndrome, although results from a recent study cast doubt over the suggestion that it has a primary causal role.

Research currently being conducted by UMIST under an agreement with FWR via WRc should provide valuable information on the effects, if any, that aluminium has on the formation of the characteristic plaques and neurofibrillary tangles associated with Alzheimer's syndrome.

A case-control study considering any association between Alzheimer's syndrome and historic exposure to aluminium in drinking water is nearing completion and much of the necessary data have been collected by MRC and WRc. However, no conclusions can be drawn until the data are statistically analysed by MRC.

Copies of the Report are available from FWR, price 25.00 less 20% to FWR Members