Chris 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 come the third most abundant element of the Earth’s crust (aluminium) is non-essential and largely inimcal 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. He 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 forms a large part of the research in our group. He is also interested in biological silicification.