ABSTRACT
Increasing public and medical interest has recently arisen concerning a possible association between human exposure to aluminium from various sources, such as drinking water, and the incidence of Alzheimer's disease in developed countries. Aluminium sulphate is widely used to provide the gelatinous precipitate of hydroxide which by physical and electrochemical means entrains the suspended and colloidal matter present in the water. A major aim of the survey was to present a clear picture of prevailing aluminium concentrations in potable water supplies in Western Europe and North America. Inspection of the data shows that there is a slight trend to higher mean aluminium concentrations in alum-treated finished waters. Comparison of alum-using works with the remainder makes it clear that aluminium levels in finished waters in the former are substantially higher than the latter. A major aim of the survey was to detect differences in aluminium residuals between alum-using and other types of treatment plants.
