Subsequent to the profiling of organometal(loid) compounds in important biogeogenic and anthropogenic deposits, the importance of this class of compounds for human health are evaluated by the analysis of both physicochemical and biological formation, distribution and transformation processes. Multidisciplinary articles written by experts from disciplines as diverse as biogeochemistry, ecotoxicology, analytical chemistry, microbiology and genetics estimate the global levels of biogeogenic and anthropogenic emissions of organometal(loid) compounds, and thus obtain  an insight to processes which influence the genesis, as well as the distribution and stability of organometal(loid) species and their interaction with each other and other matrix compounds. The authors evaluate various environmentally relevant sources from a toxicological point of view, in order to identify potential "hot spots" of organometal(loid)s, which can negatively influence ecosystems and human health.