Models of chemical fate in the environment

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Modern society benefits from the use of a large number of chemicals including petroleum and petroleum by-products, solvents, pesticides, pharmaceuticals, and fire retardants. Most are relatively innocuous and pose no threat to the health of humans or the environment on which we depend. Some, however, are problematic in that they may persist for long periods of time (e.g. PCBs), they may accumulate in organisms such as fish and birds (e.g. DDT), they may be very toxic (e.g. dioxins) and they may be transported long distances to polar regions (e.g., HCB). Rather than wait for problems to emerge (by which time it may be too late!) it is preferable to be proactive and identify problem chemicals before they contaminate the environment and cause adverse effects. The best way to accomplish this is to use mathematical models to predict how these chemicals will behave in the environment and what risk they may pose to the ecosystem.The purpose of this research project is to develop such models, test them to ensure reliability by comparing their predictions against actual observations, and to disseminate them to the user-community. This has been and continues to be the focus of the Canadian Environmental Modelling Centre at Trent University. The Centre currently disseminates models via the internet at a rate of about 500 per month to nearly 40 countries.More specifically, this project will focus on four areas. The first is chemical fate in regional environments (e.g. a Canadian province) including soils, water, sediments, and air, and exposure and risks to flora, and fauna including humans. Second is the fate of pesticides that may cause contamination of food and off-site locations. Third is indoor environments which are important because much time is spent indoors under conditions of restricted ventilation. Finally are models that will assess if a chemical is likely to be transported long distances, especially to the Canadian Arctic.