FORURENS: Integrated Modeling and Monitoring of Emerging Organic Contaminants in the Nordic Region

A key goal of environmental authorities is to minimize the exposure and effects on the environment and humans from harmful organic contaminants. A rational management of organic contaminants therefore require the determination of the quantitative relation ship between emissions, environmental levels, and human exposure to chemicals of concern (or so-called source-receptor relationships). The overall goal of the project has been to better understand and predict such relationships in the Nordic region th rough complementary integrated monitoring and modeling studies. The project has specifically targeted two emerging contaminant groups [short-chain chlorinated paraffins (SCCPs) and Volatile Methyl Siloxanes (VMS)] as well as focused on the development o f methods for screening for potential new and hitherto unknown organic contaminants among chemicals in commerce using models. The results for SCCPs show that we have a fair understanding of the link between emissions, their environmental distribution a nd uptake in the human food-chain in the Nordic environment. Yet, improved analytical methods for SCCPs are still needed as well as more accurate data on emissions. A key finding for VMS was the occurrence of selected substances (D5 and D6) in Arctic a ir at Zeppelin. These observations, in combination with a mechanistically-oriented model which reproduced the empirical data, confirm that these compounds are capable of undergoing long-range atmospheric transport to remote areas. This project has also worked on developing and evaluating a modelling-based approach to identify potentially new and unknown organic contaminants among chemicals in commerce. A number of organosilicon substances which were predicted by the model to be present in the environme nt, were later found in various environmental media in the Nordic region. This demonstrates that a multimedia model-based screening can be used to assist the discovery of environmental contaminants.

Different factors affect how organic contaminants once released into the environment distribute and accumulate, enter various food-chains, and potentially cause harmful effects in wildlife and humans over time. A sound chemical risk assessment thus requir es the determination of the quantitative relationship between emissions and human exposure. The key aim of this project is to better understand and predict relationships between environmental emissions of emerging organic contaminants and human exposure by complementary integrated monitoring and modeling studies in the Nordic region. The project is designed to target those environmental compartments and food-chains that are believed to be of greatest significance for human exposure through the environmen t. This, in order to better understand whether the integrated model is capable of describing the environmental fate and bioaccumulation of emerging organic contaminants in terrestrial and aquatic food-chains sufficiently well to serve in the assessment of the risk to humans through dietary exposure. The project is expected to lead into a number of peer-reviewed journal publications. As the results of the integrated study are expected to be of key interest to both Norwegian and Nordic environmental author ities as a higher tier tool in future screenings of new organic contaminants, we will also prepare a final report on the project whereby key methods and findings are presented and discussed. This report will be presented to relevant environmental agencies in the Nordic region at the end of the project. The final integrated model will furthermore be available through internet free of charge in a user-friendly form for anyone to download.