Using a world first technique, CSIRO has found convincing evidence that the use of alum - aluminium sulphate - to treat drinking water is safe.
"We found that the aluminium we get from alum-treated drinking water is such an insignificant amount we don't need to worry. Only 1-2% of our daily intake of aluminium comes from water and of this, only the barest trace is absorbed. Much of the aluminium that is absorbed is then excreted in urine," CSIRO scientist Dr. Jenny Stauber says.
The results have significance for water authorities around the world who use alum to clarify drinking water as part of the water treatment process. Alum is later filtered from the water, but a small fraction dissolves and is not removed.
The cause of Alzheimer's disease is subject to international research. A variety of possible causes have been considered however no link between aluminium intake and Alzheimer's has been established. However some conflicting evidence in earlier studies suggested that aluminium that is left in treated drinking water may be more readily taken up by the body than aluminium from other sources.
"Aluminium is the Earth's third most common element and occurs naturally in food and water. Most of the aluminium we consume in our food and drinking water is not absorbed and goes straight through our bodies to be excreted in faeces. What we were interested in was the trace that is absorbed into our blood," Dr. Stauber says.
"If aluminium from water were to significantly increase the total amount of aluminium in the human body, it would have to be in a form that is much more easily absorbed into our bloodstream ( i.e. more bioavailable) than aluminium in food (which has low bioavailability). This is because a greater proportion of our daily intake of aluminium comes from food," Dr. Stauber says.
"We were able to calculate that aluminium from alum-treated drinking water would
contribute less than 1 per cent to our body burden of aluminium
Contact: Dr. Jenny Stauber