Aluminium is the third most prevalent element and the most abundant metal in the earth's crust, representing approximately 8% of total mineral components.
The concentration of aluminium in food is extremely variable, due both to the original content and to food interaction with the material it contacts in storage or in cooking. For example, the aluminium content of a variety of beverages contained in aluminium cans is five to seven times higher compared to the same type of beverage from bottles.
Plants such as tea accumulate aluminium in older leaves, which may contain as much as 3 % w/w of aluminium, which explains the high aluminium concentrations in tea infusions. A high aluminium content has also been found in coffee beans, at levels comparable to those of tea leaves.
Aluminium's free metal cation, Al 3+ , is highly biologically reactive and biologically available aluminium is non-essential and essentially toxic. Biologically reactive aluminium is present throughout the human body and while, rarely, it can be acutely toxic, much less is understood about chronic aluminium intoxication.
Use of aluminium salts as coagulants in water treatment may lead to increased concentrations of aluminium in finished water. Where residual concentrations are high, aluminium may be deposited in the distribution system. Disturbance of the deposits by change in flow rate may increase aluminium levels at the tap and lead to undesirable colour and turbidity.
Aluminium toxicity
