steps in quantitative environmental Health Impact Assessment (HIA) led over time to further work, including involvement in the cost-benefit analysis of the European Commission's Clean Air for Europe (CAFE) programme, followed by some ground-breaking work on the use of life table methods to estimate the impacts of air pollution on mortality. This HIA work has expanded into health effects of other occupational and environmental pollutants and into public health more generally, leading to the establishment of the IOM's Centre for Health Impact Assessment. IOM scientists have investigated exposure of bystanders living or working near to fields that have been sprayed with pesticides and have undertaken a study to model the exposure of the British population to selected pesticides from food and other sources. This work demonstrated that although it is likely that most people are exposed to low levels of a wide variety of pesticide compounds it is unlikely that such exposure would have measurable effects on the health of the population. In 1995 the Soufriere Hills volcano on the Caribbean island of Montserrat erupted, spewing volcanic ash containing large amounts of the crystalline silica mineral cristobalite over the surrounding area. IOM scientists investigated the health of people who lived on the island. In general the exposure of the residents was low, because most people lived well away from the area of highest ash falls, and the ash proved of relatively low toxicity. The studies of the population showed no impairment of the islanders' respiratory health. Environment and health is now a well-established area of the IOM's work, involving chemical monitoring, laboratory analysis, consultancy, literature reviews and collaborative primary research. It covers exposures to and health effects of a wide range of environmental hazards, including outdoor and indoor air pollution, ionising radiation and electromagnetic fields, dioxins and pesticides. Consultancy IOM's research has helped to set standards and inform regulatory processes over the years, and this created the opportunity to offer consultancy services to customers in industry and elsewhere, to help them achieve best practice and comply with the law. Over the years, this advice has often been based on knowledge gained during their research work. The IOM have provided consultancies to a wide range of customers since the mid-1970s. In the beginning, the main impetus for the work came from Jim Dodgson, who built up occupational hygiene and chemical analysis in Edinburgh and in their regional offices (then in South