Multimedia Environmental Pollutant

McDonald JP, Gelston GM (1998) Description of the multimedia environmental pollutant assessment system (MEPAS, version 3.2), with application to a hypothetical soil contamination scenario. J Soil Contam 7(3) 283-300... 

Remedial Action Priority and Multimedia Environmental Pollutant Assessment Systems... 

The Remedial Action Priority System (RAPS) and Multimedia Environmental Pollutant Assessment System (MEPAS) are different names for an objective exposure pathway evaluation system developed by Pacific Northwest Laboratory to rank chemical and radioactive releases according to their potential human health impacts. Constituent migration and impact are simulated using air, groundwater, overland, surface water, and exposure components based on standard assessment principles and techniques. A shell allows interactive description of the environmental problem to be evaluated, defines required data in the form of problem-specific worksheets, and allows data input. The assessment methodology uses an extensive constituent database as a consistent source of chemical, physical, and health-related parameters. 

Pacific Northwest Laboratory has developed health impact assessment systems, the Remedial Action Priority System (RAPS) and the Multimedia Environmental Pollutant Assessment System (MEPAS), for the U.S. Department of Energy (DOE) to evaluate the relative importance of environmental problems. RAPS, which was developed first, applies to releases from inactive waste sites. MEPAS, the most recent version of the system, allows consideration of releases from both active and inactive sites. MEPAS differs from RAPS mainly in terms of the types of emission options. Although MEPAS retains the documented framework of RAPS (1), several enhancements have been added to the transport and exposure components (2). 

Hoopes, B. L. Walter, M. B. Supplemental Mathematical Formulations The Multimedia Environmental Pollutant Assessment System (MEPAS) PNL-7201, Pacific Northwest Laboratory, Richland,... 

Droppo, J. G. Jr. Strenge, D. L. Buck, J. W. Hoopes. B. L. Brockhaus, R. D. Walter, M. B. Whelan, G. Multimedia Environmental Pollutant Assessment System (MEPAS) Application Guidance Volume 1 - User s Guide PNL-7216, Pacific Northwest Laboratory, Richland, Washington, 1989. 

Richardson, S. 1991. Multimedia environmental concerns in warp sizing Low tech approaches to waste reduction, North Carolina Pollution Prevention Program, Raleigh, NC (February). 

The P2 Act is an attempt by the U.S. to establish a framework for integrated multimedia environmental initiatives. The P2 Aet provides for a multimedia, integrated, and cost-effective approach to solving environmental problems while encouraging sustainable development. P2 or source reduction includes any practice that reduces or eliminates the creation of pollutants through increased efficiency in the use of raw materials, energy, water, or other resources, or protection of natural resources by conservation. Pollution... 

Multimedia models can describe the distribution of a chemical between environmental compartments in a state of equilibrium. Equilibrium concentrations in different environmental compartments following the release of defined quantities of pollutant may be estimated by using distribution coefficients such as and H s (see Section 3.1). An alternative approach is to use fugacity (f) as a descriptor of chemical quantity (Mackay 1991). Fugacity has been defined as fhe fendency of a chemical to escape from one phase to another, and has the same units as pressure. When a chemical reaches equilibrium in a multimedia system, all phases should have the same fugacity. It is usually linearly related to concentration (C) as follows ... 

To address media-specific problems, single-media models for air, surface water, groundwater and soil pollution have been developed and used by different disciplines. Although these models generally provide detailed description of the pollutant distribution in space and time and incorporate mass transfer from other media as boundary conditions, they are not capable of characterizing the total environmental impact of a pollutant release. Multimedia models have been, therefore, developed to predict the concentration of chemicals in multiple environmental media simultaneously with consideration of chemical transport and transformation within and among media [1],... 

A multimedia concept that reduces or eliminates pollutant discharges to air, water, or land and includes the development of more environmentally acceptable products, changes in processes and practices, source reduction, beneficial use, and environmentally sound recycling. ... 

Indeed, OCPs, once released into the environment, are distributed into various environmental compartments (e.g., water, soil, and biota) as a result of complex physical, chemical, and biological processes. In order to perform appropriate exposure and risk assessment analyses, multimedia models of pollutant partitioning in the environment have been developed. Properties which are at the base of such a partitioning are water solubility (WS), octanol-water partition coefficient (Ko ), soil adsorption (K ), and bioconcentration factors (BCFs) in aquatic organisms, following these four equilibriums ... 

First, environmental lead is a multimedia pollutant. It travels various pathways in various environmental media (e.g., air, water, dusts) to impart potentially toxic lead exposures in humans. This characteristic requires that specific lead exposure settings be characterized and quantified, along with the identification of principal and likely sources of lead. By contrast, lead contamination has typically been addressed legislatively and through regulatory actions on a medium-specific basis by some particular agency with the mandated jurisdiction and responsibility for the medium. 

Lead is a multimedia pollutant, i.e., it provides exposures through diverse environmental media. The specific characteristics of each environmental contributor, such as Pb concentrations and intake amounts of some environmental medium, help determine the extent to which different individuals and populations sustain actual exposures. This also means that while some Pb sources can be characterized on a national, international, or other macroscale as being significant, the actual sources and pathways in specific cases for substances such as lead or other elements require specific evaluation. Some segments of human populations may sustain exposures from Pb in more than one environmental medium, in which case one employs methods to sort out potential contributions or the relative total contributions to total exposures. 

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