The Birchall Centre, Lennard-Jones Laboratories, Keele University, Keele, Staffordshire, UK.
Before it is possible to begin to understand the chemistry of human exposure to aluminium, it is necessary to appreciate a few basic rules. Rule number one tells us that the form of aluminium which is bound by functional groups on biomolecules is its free trivalent aqueous cation, Al. Rule number two tells us that the binding of Al is determined by both thermodynamic and kinetic constraints. Rule number three tells us how essential it is to understand the critical importance of the exposure regime. The application of these simple rules of aluminium chemistry allows us to understand why, for example, not all aluminium salts are equal and not all routes of aluminium exposure are equivalent.