A mass balance modelling framework for chemicals and their primary metabolites for ecological and human health assessment – Year two

Chemicals manufactured and used in society degrade through physical and biological processes (e.g., photolysis, biotransformation) into break-down products (e.g., metabolites). Most “parent” chemicals can breakdown relatively quickly so that they are not persistent or bioaccumulative; however, some metabolites formed during the degradation processes can persist in the environment thus requiring consideration for ecological and human health assessment. The environmental fate, bioaccumulation, exposure and associated risks of these formed metabolites are largely unknown. The proposed research includes the development and testing of an exposure modelling framework for the holistic assessment of parent chemicals and their primary metabolites formed during degradation processes in the environment (e.g., air, water) and in biota. This research will combine Quantitative Structure-Activity Relationship (QSAR) methods and mechanistic, multi-media environmental fate and exposure models. QSAR models will be developed to estimate degradation properties (e.g., reaction rates, half-lives) and databases and models will be used to estimate metabolite formation pathways. The Risk Assessment IDentification And Ranking (RAIDAR) multi-media mass balance model will be revised to incorporate this information and quantify the fate and exposure of parent chemicals and selected metabolites to humans and ecological receptors. Case studies will be performed to evaluate the performance of the new modelling framework.

Faculty Supervisor:

Frank Wania

Student:

Alessandro Sangion

Partner:

Arnot Research and Consulting Inc.

Discipline:

Environmental sciences

Sector:

Professional, scientific and technical services

University:

University of Toronto