Aluminium

Aluminium occurs naturally in some raw water sources and it is commonly used as a coagulant in water treatment processes. In normal circumstances the aluminium is converted to an insoluble form and is thus removed from the water. It is important that residual levels remain well below the maximum admissible concentration of 0.2 mg/l.It has been suggested that there might be an association between aluminium in water supplies and dementia; however there is no firm evidence to support this. A specialised health hazard arising from the presence of aluminium in the water is that patients on kidney dialysis machines can be fatally affected if the supply to the machine contains soluble aluminium.