Multimedia pollutants

Bennett, D. H., et al. (2002) Intake fraction for multimedia pollutants a tool for life cycle analysis and comparative risk assessment. Risk Analysis 22 905-918. 

McKone TE and MacEeod M (2004) Tracking multiple pathways of human exposure to persistent multimedia pollutants Regional, continental, and global scale models. Annual Reviews of Environment and Resources 28 463-492. 

Chadha, N. (1994), Develop Multimedia Pollution Prevention Strategies, Chemical Engineering Progress, Vol. 90, No. 11, pp. 32-39. 

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. 

In 1980, Mushak and Schroeder authored the first report to a U.S. Federal agency that focused exclusively on the science of lead within a multimedia pollutant framework. It was combined with the legislative history of lead and other multimedia pollutants (Mushak and Schroeder, 1980) with reference to effectiveness. This report to the U.S. National Commission on Air Quality was summarized and cited in the Commission s report. To Breathe... 

Lead acts as a multimedia pollutant in the human environment. Multimedia pollutants are complex to regulate because of some larger realities. For example, what are the major sources and pathways for the contaminant in terms of human exposures on either a national or case-specific basis How well are levels in the major media controlled relative to concentrations in the minor media and vice versa" ... 

Lead s behavior as a multimedia pollutant poses problems for human health risk assessment and regulatory science at several levels, a number of which are presented in detail in later chapters. First, it is important to establish the full extent of lead exposures of human populations, especially those subsets of the population at elevated risk for exposure and/or harm. Establishing the extent of exposure mainly includes identifying and quantifying lead intakes and uptakes into the human body. 

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. 

Lead is a multimedia pollutant and consequently has impacts on human populations via their contact with diverse Pb-contaminated media. Multiple media intakes and uptakes provide a cumulative, integrated internal body level of Pb and integrated expressions of Pb in the body are what are quantitatively linked to Pb poisoning risks. While Pb is a multimedia contaminant, not all media in all places or at all times are equally contaminated or provide comparable human exposures. The relative significance of Pb in some particular medium or medium type differs from case to case and from exposure scenario to exposure scenario. 

Mushak and Schroeder (1980) addressed this disparity between singlemedium legislative mandate and multimedia pollutant science in two reports to the U.S. National Commission on Air Quality (Mushak and Schroeder, 1980 Schroeder and Mushak, 1980). In the report dealing with the legislative history of multimedia pollutants, Schroeder and Mushak (1980) noted the origins of the media-specific fragmentation of regulatory control for environmental contaminants and used a set of case studies to describe the effects of such piecemeal control for lead. 

Other regulatory classes of multimedia pollutants are within the purview of the CAA. Section 112 gives the EPA Administrator the authority to control air pollutants such as Pb which are not identified as criteria pollutants but entail emissions from new or existing sources of pollutants, via National Emission Standards for Hazardous Air Pollutants (NESHAPS). Here, the Administrator must first determine that the HAPs can cause or are expected... 

Section 104 of the CWA provides sufficient authority to the EPA Administrator in the areas of research and data collection for the Agency to conduct and promote coordination of research, investigations, experiments, surveys, and studies ... relating to the causes, effects. .. reduction. .. and elimination of pollution. [ 104(a)(l)]. The CWA [ 104(c)] also allows cooperative administrative efforts on research with agencies such as the ... Secretary of Health, Education, and Welfare (now Health and Human Services). For multimedia pollutants like Pb, there is the statutory wherewithal to look at Pb contained in environmental media other than ambient waters. 

Priority setting under RCRA is one mechanism for addressing multimedia pollutants such as lead and lead compounds in solid wastes, but the feasibility of that approach may be problematic, given the large listings of hazardous chemicals within all three bodies of legislation with potential multimedia dimensions RCRA, the CWA, and the SDWA. RCRA itself lists lead acetate, lead phosphate, lead subacetate, lead compounds not otherwise specified. 

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