Exposure Models

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Modelling the Environment

Our goal in studying the fate of a compound is to understand its concentration in the environment. Exposure modelling is the point at which we combine all the information we learned in our QSPR and fate process research to generate environmental concentrations in wastewater treatment plant effluents, rivers, oceans, sediments and soils. We generate these environmental concentrations for hundreds of countries worldwide.

To be able to cover so much of the world, we use mathematical equations. These equations are put into computer programs and are called Exposure Models.

Most P&G ingredients are extensively removed during sewage treatment and only small amounts enter the environment. To predict how much gets to the environment, models have been developed for all environmental compartments (treatment plants, air, soil, water, sediment) in which a product ingredient could reside. These models include municipal and onsite wastewater treatment (ASTreat, SepTTS), receiving rivers (GIS-ROUT, GREAT-ER, Tamagawa, Blackwater), estuaries (ESTUARY), groundwater and soil systems (SepTTS, SLUDGE, FOCUS). As our scientific knowledge grows, these models are continually being updated.

For more information on how we use GIS-ROUT, GREAT-ER to integrate exposure concentrations with the health of organisms in the environment, see our Eco-Epidemiology page.

Exposure modelling is vitally important to the environmental risk assessment process for two reasons. First, with the right input data, modelling can be a fast and accurate approach to estimating environmental concentrations. Time and effort saved at this point in our risk assessment procedure frees P&G scientists to work on more complex issues.

Second, modelling enables us to estimate environmental concentrations in thousands of places all around the world. This is far more areas that we could ever visit and study.

Hence, all risk assessments rely on environmental models to some extent. However, when environmental models are not sufficient to answer our questions about environmental concentration, the next step is environmental monitoring.