WIT Press

An Overview Of USEPA’s Integrated Multi-media, Multi-pathway And Multi- Receptor Exposure And Risk Assessment Tool – The 3MRA Model


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WIT Press


B. Johnson, S. Kroner, D. Cozzie & Z. Saleem


An overview of USEPA’s integrated multi- media, multi-pathway, and multi-receptor exposure and risk assessment tool - The 3MRA Model B. Johnson, S. Kroner, D. Cozzie, & Z. Saleem US. Environmental Protection Agency, Office of Solid Waste United States Abstract Risk based tools are often useful for making quick yet informed decisions regarding the threats posed by a waste, an emission, or a remedial setting. Such tools may prove useful in Brownfields settings where the primary objective is returning properties to productive use in the most efficient manner possible. This paper chronicles the development of a state-of-the-art risk based standard setting tool, USEPA’s Multi-media, multi-pathway, multi-receptor exposure and risk assessment tool -the 3MRA model. The history of its development, nature of the data, the establishment of a site-based approach, the underlying Monte Carlo scheme, the unique software design, and the potential future applications are summarized. 1 Background In the 1990‘s there was a substantial effort by Academia, Federal and State organizations and the private sector to develop risk assessment tools that could be used to help establish risk-based screening levels. These levels, depending on how they are developed, can be used to help inform a variety of decisions such as the need to initiate or complete remediation, where and how to manage wastes, or to help decide whether technology based standards are protective of human health or the environment. Similar decisions need to be made at Brownfield sites and the