into the causes of this disease. Under Dr Jim Vincent's leadership, an innovative research programme, begun by Dr Trevor Ogden, was aimed at designing new sampling instruments for coarser aerosols. The culmination of this work was the development of the IOM inhalable dust sampler, which has become established as the device of choice for measuring the part of an aerosol that penetrates beyond the larynx. IOM scientists played a key role in defining the internationally agreed size fractions of dust relevant to human lung disease, i.e. inhalable, thoracic and respirable. Research on chemical exposure has more recently focussed on exposure modelling, data management and studies for regulatory risk assessment. Studies in relation to metals, including dermal exposure to nickel, zinc and lead, have been carried out. Work on the measurement of exposure to oil mist aerosol and vapour has been undertaken for offshore oil workers. In collaboration with some of the leading European human exposure scientists, IOM has been developing a new generation exposure model for use in connection with the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulations in Europe – the model is known as the Advanced REACH Tool or ART. IOM scientists have developed a strong interest in the assessment of dermal exposure, leading to the enumeration of new principles of exposure assessment, the development of predictive exposure models, and investigations into dermal exposure under specific working conditions. Estimating historical skin exposures of farmers dipping sheep in pesticide solutions for an epidemiological study proved particularly challenging, but this research demonstrated a strong association between concentrated organophosphate pesticides and neurological symptoms. As a consequence the UK government withdrew these pesticides from the market until safer handling systems were devised. In addition, new sampling instruments to measure dermal exposure to chemicals and new theoretical models to help understand how skin exposure may arise. These instruments and models may in the future help provide more reliable assessments of the risks from chemicals to the skin. IOM scientists are also developing a molded cassette with a 15mm inlet for use as a personal sampling pump to test inhalable dust levels. Other research at IOM has shown that chronic fatigue is common amongst those who consider their health is affected by pesticides and suggested there was an association between exposure to organophosphates and chronic fatigue symptoms. Human sciences and personal protective equipment Early ergonomics research at IOM, particularly under the direction