Open Access

Organophosphorus flame retardants and plasticizers (OPEs) have been utilized for decades as plasticizers and, to a lesser extent, as flame retardants in various consumer products to improve their material properties. With the restriction and ban of the widely used brominated diphenyl ethers (PBDEs) by, ultimately, the Stockholm Convention due to their adverse effects on humans and the environment, the use of OPEs as replacements has increased rapidly. However, the potential adverse properties, environmental distribution and fate of OPEs are insufficiently understood. The research presented in this thesis investigated the occurrence, distribution and transport of OPEs with a focus on the coastal and estuarine environment. Due to the wide range of physicochemical properties of OPEs, the environmental fate and behaviour of OPEs was investigated over a range of compartments, starting from the atmospheric occurrence to the aquatic phase and the behaviour in sediments. The aim was to gather information on the OPE contamination situation in the coastal and estuarine environments, to identify specific contamination patterns for source assessment and to investigate the distribution behaviour of OPEs between gas- and particle-phases to evaluate their environmental transport mechanism. To achieve these scientific goals, sensitive and robust chemical analytical methods for the detection and quantification of OPEs in a variety of environmental samples using gas-chromatography coupled with tandem mass spectrometry were developed. Water samples were removed along the Elbe and Rhine Rivers to test the hypothesis of whether specific point sources, such as wastewater treatment plants, are the major input pathways for OPE contamination in rivers. A total of 65 water samples, including an intensive measurement campaign during the flood event in 2013 at the Elbe, was taken and analysed for OPEs. No obvious point sources were identified along either of the rivers analysed. No significant increase or decrease in the OPE concentrations or a change in patterns were observed over a transect of over 300 km at the Elbe, with an increase in water discharge of 2.5. This finding suggested that the OPE input in large rivers is primarily driven by diffuse sources, such as surface runoff, or by minor point sources rather than local point sources. To examine the specific pattern of OPE contamination in individual rivers and estuaries, 37 sediment samples from 8 rivers in Europe and China were analysed. With this analytical data, a fingerprint analysis of the OPE patterns identified could be conducted. All the rivers investigated in Europe displayed a very similar fingerprint, which can be explained by the common European market with consistent legislative regulations. In contrast, the fingerprint from China differed significantly from the one in Europe. For example, in China, the OPE restricted in Europe, Tris(2-chloroethly)phosphate, was found to be one of the major OPE components, while Tris(2-butoxyethyl) phosphate, a major compound in Europe, was negligible in China. The investigation showed that the fingerprinting analysis is a useful tool to identify different regions or characterize specific rivers regarding their OPE contamination. In addition, it could be shown that legislative restriction and processes have an impact on local or even EU-wide contamination patterns. At a coastal site next to the German city of Büsum, 58 air samples were taken over one year. Using the newly developed analytical method, it was possible to analyse the gas, as well as the particle phase, of the samples collected with very low detection limits for OPEs. In contrast to expectations, no annual trend in OPE concentrations, phase distributions or patterns was observed, but the investigation of the phase distribution challenged the previous scientific consensus that OPEs occur as primarily bound to particles in the atmosphere. Several compounds were detected in significant amounts in the gas phase. To validate these novel results, a model analysis based on the chemical properties of OPEs was conducted using three different phase distribution models. The results from the environmental data were strongly supported by the simulations, and the formal knowledge could be refuted. Consequently, the atmospheric transport assumptions and estimations about the long-range transport of OPEs have to be reassessed because compounds in the gas phase undergo other types of transport degradation and elimination mechanisms than particle-boundones. The novel findings presented in this thesis challenged an important aspect regarding the perceived scientific knowledge about the behaviour of OPEs in the environment and call on the scientific community to reassess the environmental behaviour of OPEs. The insights presented on the patterns highlight the impact of environmental policies and regulatory mechanisms to work towards the final goal of a good environmental status and the avoidance of adverse effects of discarded chemicals on humans and the environment.