Pure and Applied Chemistry

Abstract: Polychlorinated dioxins and dibenzofurans are two series of tricyclic aromatic compounds, which have been the focus of the interest in the last decades; in all there exist more than 200 congeners. They are formed in numerous ways, primarily in incineration processes and in industrial processes. It has also been found that they are formed by natural processes. They are ubiquitous and have been quantified in abiotic samples such as soil, sediments and air as well as in living organisms, primarily aquatic organisms. A dramatic decrease in most environmental concentrations including biological and human samples of PCDDs and PCDFs has been identified. There is a discrepancy between sources and environmental reservoirs which cannot be fully explained.