Environmental fate and risk assessment tool

Despite the existence of several databases for certain substances, it is not possible to find physicochemical and/or toxicological parameters to assess the risk for all substances. The lack of data is one of the main problems in risk assessment. This is especially true for emerging pollutants. One solution to solve this problem is the use of QSAR or estimation tools. QSAR models correlate the structure of the substance with their activities (physicochemical properties, environmental fate, and/or toxicological properties). 

Exposure Assessment. As noted above, the Risk Assistant software is intended to build on EPA s existing information base on environmental fate and transport modelling, extending it to risk-relevant exposure calculations. Accordingly, it does not incorporate mathematical models of the environmental transport and fate of chemicals, but takes as its starting point user-specified data on environmental concentrations of chemicals to which people might be exposed. The Additional Analyses discussed below, however, do include tools to assist the risk assessor in selecting appropriate transport models. 

CIBA GEIGY Corporation is presently using models as an aid to data interpretation for risk assessment. Our general philosophy is to use the model as an aid to risk assessment and not as a predictive tool to eliminate definitive studies. Hopefully, environmental fate models will be useful as a predictive tool as they become validated. 

In this chapter, a brief description of the concepts and tools available for multimedia modelling to support the environmental risk assessment is given. The environmental fate assessment is the base of a more complex study, the... 

In order to achieve that an environmental fate model is successfully applied in a screening level risk assessment and ultimately incorporated into the decisionmaking tools, the model should have computational efficiency and modest data input. Moreover, the model should incorporate all relevant compartments and all sources of contamination and should consider the most important mechanisms of fate and transport. Although spatial models describe the environment more accurately, such models are difficult to apply because they require a large amount of input data (e.g., detailed terrain parameters, meteorological data, turbulence characteristics and other related parameters). Therefore, MCMs are more practical, especially for long-term environmental impact evaluation, because of their modest data requirements and relatively simple yet comprehensive model structure. In addition, MCMs are also widely used for the comparative risk assessment of new and existing chemicals [28-33]. 

Since traditionally pharmaceuticals have not been considered as environmental contaminants, the study of their presence in the environment is in some ways a new area of research which has taken off recently. Nonetheless, so far, there is little knowledge on their occurrence, fate and environmental assessment, an essential tool for the implementation of minimizing measures and risk management. Potential risks associated with releases of pharmaceuticals into the environment have become an increasingly important issue for pharmaceutical industry and environmental regulators [7, 11]. 

SimpleBox was created as a research tool in environmental risk assessment. Simple-Box (Brandes et al. 1996) is implemented in the regulatory European Union System for the Evaluation of Substances (EUSES) models (Vermeire et al. 1997) that are used for risk assessment of new and existing chemicals. Dedicated SimpleBox 1.0 applications have been used for integrating environmental quality criteria for air, water, and soil in The Netherlands. Spreadsheet versions of SimpleBox 2.0 are used for multi-media chemical fate modeling by scientists at universities and research institutes in various countries. SimpleBox models exposure concentrations in the environmental media. In addition to exposure concentrations, SimpleBox provides output at the level of toxic pressure on ecosystems by calculating potentially affected fractions (PAF) on the basis of species sensitivity distribution (SSD) calculus (see Chapter 4). 

Product stewardship means "responsibly managing the health, safety, and environmental aspects of raw materials, intermediate, and consumer products throughout their life cycle and across the value chain in order to prevent or minimize negative impacts and maximize value" [7], Chapter 2 of this book discusses the technical tools that a product steward uses to achieve this goal. These tools include the techniques to characterize and predict the fate and transport of chemicals in the environment upon their manufacture and use. The tools also include the methods used to calculate the possible risks to human health and the environment that may result. Chapter 2 also describes the formal process of life cycle assessment, which uses these tools to evaluate the potential effects on the environment as a result of the production, use, and disposal or recycling of a product. 

---