You are here:
A Chemical Activity Approach to Exposure and Risk Assessment of Chemicals
Citation:
Gobas, F., P. Mayer, T. Parkerton, R. Burgess, D. van de Meent, AND T. Gouin. A Chemical Activity Approach to Exposure and Risk Assessment of Chemicals. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, 37(5):1235-1251, (2018).
Impact/Purpose:
In 2012, the National Academies of Sciences established a vision for exposure and risk assessment in the twenty-first century, this article highlights the application of a thermodynamic chemical activity approach for the exposure and risk assessment of chemicals in the environment. The activity approach is a system for expressing the exposure of chemicals in different environmental phases (e.g., water, sediment, air, tissue) normalized to a thermodynamic state (e.g., the chemical's water solubility). This allows for a determination of where a chemical is travelling in the environment. For example, if a chemical is at equilibrium (i.e., not moving between phases), all of the activities in the various phases would be very similar. The present article describes the chemical activity approach, its strengths and limitations, and provides examples of how this concept may be applied to the management of single chemicals and chemical mixtures.
Description:
To support the goals articulated in the vision for exposure and risk assessment in the twenty-first century, we highlight the application of a thermodynamic chemical activity approach for the exposure and risk assessment of chemicals in the environment. The present article describes the chemical activity approach, its strengths and limitations, and provides examples of how this concept may be applied to the management of single chemicals and chemical mixtures. The examples demonstrate that the chemical activity approach provides a useful framework for 1) compiling and evaluating exposure and toxicity information obtained from many different sources, 2) expressing the toxicity of single and multiple chemicals, 3) conducting hazard and risk assessments of single and multiple chemicals, 4) identifying environmental exposure pathways, and 5) reducing error and characterizing uncertainty in risk assessment. The article further illustrates that the chemical activity approach can support an adaptive management strategy for environmental stewardship of chemicals where “safe” chemical activities are established based on toxicological studies and presented as guidelines for environmental quality in various environmental media that can be monitored by passive sampling and other techniques.
