Our research strives to improve the scientific understanding of the potential hazards and risks chemicals may cause to humans and the environment. Often measured information is limited and there is a recognized need to minimize animal testing. It is not possible to measure “all of chemicals in all things” for chemical assessments due to analytical limitations and enormous financial costs. To address these issues, we develop and evaluate databases of measured information and develop and evaluate models based on measured data and scientific theory. The models can be used to interpret the measured data and to complement measurements by addressing data gaps for chemical assessments. The models also can be used to make predictions (hypotheses) to guide research needs (e.g. when there are no measured data) and to inform experimental testing. In turn the model predictions (hypotheses) can be tested with new measurements. This iterative process of model development, prediction and testing is envisaged to improve scientific understanding and provide confidence in applying the models for chemical assessments. Some of the models we have developed are used in regulatory programs and these models can also be used to promote “green chemistry” and sustainability. 



Chemical risk assessment relates to quantifying the proximity of chemical exposure concentrations to chemical concentrations associated with effects and estimating the uncertainty in these calculations. We develop, apply and evaluate mass balance models to simulate and assess chemical fate and transport in the environment, bioaccumulation in organisms and in food webs, aggregate exposures to humans and ecological species through contact with chemicals in environmental media (air, water, soil, sediment and food), and potential risk. 

The databases of chemical information are used to develop, apply and evaluate Quantitative Structure-Activity Relationships (QSARs) to estimate key chemical properties such as partition coefficients, biodegradation half-lives (e.g., by microorganisms), and biotransformation half-lives in organisms (e.g., in fish and mammals). This chemical information is used in hazard, exposure and risk assessment.