US Associate Editor 54N J. Environ. Monit., 1999, 1 distinction constituting a substantial and original contribution to science’. He is widely experienced in the occupational and environmental health sciences. He has worked in industry, in non-academic research institutions, and in three universities (Strathclyde University in Britain where he taught physics, University of Minnesota, and—now— University of Michigan).His work over the past 30 years has included studies in aerosol science and fluid mechanics, and their application to the atmospheric transport of pollutants, emission control from large-scale industrial processes, exposure assessment and control of airborne pollutants in environmental and occupational settings, inhalation toxicology and pharmacokinetics, occupational exposure standards setting, and international occupational health policy.In these areas he has published close to 200 works. He is a Past- President of the British Occupational Hygiene Society, is the current Chair of the Air Sampling Procedures Committee of the American Conference of Governmental Industrial Hygienists, and has just stepped down as Editor-in- Chief of the Journal of Aerosol Science after 11 years in that capacity.In 1994 he was awarded the Sinclair Award, the premier recognition of the American Association for Aerosol Research. In 1998 he received theMeritorious Achievement Award from the American Conference of Government Industrial Hygienists. He is currently the Chair of the Department of Environmental and Industrial Health at the University of Michigan, and remains active in a wide range of research areas.Professor James H. Vincent Professor Vincent’s academic background is in physics, holding a Ph.D. from the University of Durham, UK. He also holds a D.Sc. from the same institution, awarded in 1991 in consideration of ‘....work of high Draft IUPAC Recommendations on Chemical Speciation and Fractionation of Trace Elements The eVect of trace elements in living sytems, in food and in the enviroment depends on the chemical form in which the elements enters the system and the final form in which it is present.It is necessary to determine the various forms in which the trace element is present to meet pressing occupational, environmental, regulatory and economic needs for understanding mobility, bioavailability, storage, retention and toxicity.In an attempt to end the present confusion regarding the usage of the term speciation, three IUPAC Commissions have collaborated to evaluate this issue. This paper presents definitions for the concepts related to speciation of trace elements, more particularly speciation analysis and species in chemistry.A categorization of species is proposed according to the isotopic composition of the element, its oxidation state, the inorganic compounds and organic complexes of which the trace element forms a part, and its occurrence as an organometallic compoud or as a macromolecular complex. A general outline is given of the analytical methods used in speciation analysis, including (with definition) fractionation. An outline of methodology of dynamic metal speciation analysis and of methodological approaches available for speciation analysis is also presented. Anyone wishing to review this document may obtain a copy from AlanMcNaught at the Cambridge oYce of the Royal Society of Chemistry [tel.+44 (0) 1223 432119, e-mail adm@rsc.org]. The deadline for receipt of comments is 29th February 2000.