"The initial training network CSI: ENVIRONMENT aims at training 16 young scientists in the discipline of compound-specific isotope analysis (CSIA) for environmental and forensic investigations. Linking sources and sinks of organic contaminants is a major challenge in contemporary environmental science. Chemicals can be released to the environment when leaving their field of application, intended or accidentally. It is a challenge to relate the origin of spills, transport and subsequent distribution in the environment and to analyse potential sinks and elimination pathways at a local, regional and global scale. This network brings together international experts in the field of isotope chemistry and related fields for training the next generation of young scientists in the field of environmental forensics using stable isotope techniques. Isotope analysis offers a unique opportunity to obtain information of sources, transport, degradation pathways and sinks of contaminants in the environment which will be urgently needed in the future. Multi-element isotope fingerprinting of chemically complex substances can be used to elucidate transformation pathways making use of isotope fractionation processes altering the reactive position and to analyse the isotope composition of an organic molecule to track sources. Concepts and applications are available for the more simple organic contaminants such as BTEX, chlorinated ethenes and MTBE but not for more complex organic contaminants such as pesticides or brominated flame retardants. Thus, the aim of this ITN is to train young scientist in development of concepts for the application of isotope tools to assess the fate of organic chemicals in the environment. Young scientists will be educated in the field of isotope forensics, pushing forward the frontiers of current isotope techniques to develop new areas of isotope applications in both fundamental and applied environmental sciences."