Dr. Christopher Exley is the Reader in Bioinorganic Chemistry at The Birchall Centre, Keele University in Staffordshire and Honorary Professor at the UHI Millennium Institute. Exley is a biologist (University of Stirling) with a PhD in the ecotoxicology of aluminium (University of Stirling). His research career (1984-present) has focused upon an intriguing paradox; ‘how the third most abundant element of the Earth’s crust (aluminium) is non-essential and largely inimical to life’. Investigating this mystery has required research in myriad fields from the basic inorganic chemistry of the reaction of aluminium and silicon to the potentially complex biological availability of aluminium in humans. Exley is also fascinated by the element silicon in relation to living things which, as the second most abundant element of the Earth’s crust, is also almost devoid of biological function. One possible function of silicon is to keep aluminium out of biology (biota) and this area of study forms a large part of Exley’s research.