The impact of aerosols on human health is increasingly discussed in the recent years. However, the firm assessment of the health risk due to exposure to aerosols is hindered by a lack of sufficient supporting data. Because the highest levels to aerosols are likely to be encountered in workplaces, protection of health of exposed workers by implementation of adequate protective measures is a priority. The research in this area includes identification of sources of exposure, exposure assessment, detailed characterization of the aerosol materials and biological effects thereof as well as the development of appropriate protective measures. A program of screening measurements and evaluation of protective measures at selected workplaces was recently launched by the Occupational Safety Research Institute (VÚBP) in Prague. In this paper, an example of the aerosol exposure assessment in a metallurgical plant as well as its interpretation is presented. Based on both the experimental findings and critical analysis of the current knowledge it is concluded that the presence of aerosols in workplace air is an important issue of occupational safety and health, deserving systematic attention and qualified management.