Sediment quality criteria

Apart from the assessment and prognosis of effects of sediment-associated pollutants on benthic organisms (6.1.) and potential hazards on groundwater quality (6.3), three major reasons have been given for the establishment of sediment quality criteria  

Efforts have been undertaken mainly be the United States Environmental Protection Agency to develop standard procedures and criteria for the assessment of environmental impact of sediment-associated pollutants. Initial discussions (Anon., 1984, 1985) suggested five methodological approaches which merit closer consideration (i) background approach , (ii) water quality/pore water approach , (iii) sediment/water equilibrium partitioning approach , (iv) sediment/organism equilibrium approach, and (v) bioassay approach. Of these possibilities, applications of bioassays and background approach have been outlined in sections 6.1 and 6.2, respectively. 

Biological criteria exhibit major advantages in that they integrate effects of multiple factors including sediment characteristics and complex or unknown wastes, and, with respect to field surveys, that they are site-specific, requiring minimum extrapolations. On the other hand, field surveys are costly and bioassay organisms may not represent sensitivity of the natural species assemblage Anderson et al., 1987). 

Major advantages of numerical criteria lie in their easy application and amendment to modeling approaches. However, if criteria do not exist for certain chemicals of concern, a biological test may still be required. In addition some equilibrium modeling approaches will fail if tissue concentration and toxicity is independent (Chapman et al., 1987). 

Sediment/water equilibrium partitioning. This approach is related to a relative broad toxicological basis of water quality data. The distribution coefficient Kp, which is determined from laboratory experiments, is defined as the quotient of equilibrium concentration of a certain compound in sediment (Csx, e.g. in mg/kg) and in the aqueous phase (Cwx e.g. in mg/1). In practice, three categories of compounds can be distinguished  

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As is the case with assessments of the toxicity of dissolved trace metals, the development of sediment quality criteria (SQC) must be based on the fraction of sediment-associated metal that is bioavailable. Bulk sediments consist of a variety of phases including sediment solids in the silt and clay size fractions, and sediment pore water. Swartz et al. (1985) demonstrated that the bioavailable fraction of cadmium in sediments is correlated with interstitial water cadmium concentrations. More recent work (e.g., Di Toro et al, 1990 Allen et al., 1993 Hansen et al, 1996 Ankley et ai, 1996, and references therein) has demonstrated that the interstitial water concentrations of a suite of trace metals is regulated by an extractable fraction of iron sulfides. 

Ankley, G. T., Di Toro, D. M., Hansen, D. M. and Berry, W. J. (1996). Technical basis and proposal for deriving sediment quality criteria for metals. Environ. Toxicol. Chem. 15,2056-2066. 

Di Toro DM, Zarba CS, Hansen DJ et al (1991) Technical basis for establishing sediment quality criteria for non-ionic organic chemicals using equilibrium partitioning. Environ Toxicol Chem 10 1541-1583... 

Chapman PM. 1989. Current approaches to developing sediment quality criteria. Environ Toxicol Chem 8 589-600. 

U.S. EPA. Sediment quality criteria for the protection of benthic organisms acenaphthene. Office of Science and Technology, Report 822-R-93-013, 1993, 90 p. 

Ditoro, D.M., C.S. Zarba, D.J. Hansen, W.J. Berry, R.C. Swartz, C.E. Cowan, S.P. Pavlou, H.E. Allen, N.A. Thomas, and P.R. Paquin. 1991. Technical basis for establishing sediment quality criteria for nonionic organic chemicals using equilibrium partitioning. Environ. Toxicol. Chem. 10(12) 1541-1583. 

Shea D. 1988. Developing national sediment quality criteria. Environ. Sci. Technol. 22, 1256-1261. 

Di Toro, D.M., Zarba, C., Hansen, D.J., Berry, W., Swartz, R.C., Cowan, C.E., Pavlou, S.P., Allen, H.E., Thomas, N.A., Paquin, P.R., 1991. Technical Basis for Establishing Sediment Quality Criteria for Non-ionic Organic Chemicals Using Equilibrium Partitioning. Environ. Toxicol. Chem. 11, 1541-1583. 

Chemical Mean concentration in Hong Kong s marine sediment (pg kg-1 dw)b Screening sediment quality criteria Reference... 

Table 15.8. Minimum, maximum and average concentrations of major organochlorine contaminants in ng g and corresponding sediment quality criteria... 

Sediments can be relocated within water bodies only if they meet certain quality requirements. In Europe, this is known as the eco-political objective. However, a generally accepted concept to adequately define sediment quality criteria is still lacking, because effects-based scientific knowledge still needs to grow to ameliorate management guidelines and regulations. 

Chapman, P.M. (1986) Sediment quality criteria from the Sediment Quality Triad - an example, Environmental Toxicology and Chemistry 5, 957-964. 

USEPA] US Environmental Protection Agency. 1986. Sediment quality criteria methodology validation calculation of screening level concentrations from field data. Washington US Environmental Protection Agency Report No EPA822R86101. 

USEPA (1993) Technical Basis for Deriving Sediment Quality Criteria for Non-ionic Contaminants for the Protection of Benthic Organisms by Using Equilibrium Partitioning, EPA 822-R-93-011. US Environmental Protection Agency, Office of Water, Washington, DC. 

Swartz, R.C., D.W. Schults, T.H. Dewitt, G.R. Ditsworth, and J.O. Lamberson. 1990. Toxicity of fluoranthene in sediments to marine amphipods a test of the equilibrium partitioning approach to sediment quality criteria. Environ. Toxicol. Chem. 9 1071-1080. 

Contents Indude exposure assessment, maximum acceptable tissue concentrations (MA TCs), uncertainty factors, deriving MA TCs, the toxidty reference value, sediment quality criteria, and chemical spedtic and multi-contaminant ecosystem MA TCs. 

Evaluation of the AET as a Basis for Setting Sediment Quality Criteria... 

The assessment of the environmental impact of particle-bound contaminants, i.e. the development of sediment quality criteria (Chapter 6). 

Risk assessment and sediment quality criteria. Risk assessment does not necessarily represent an ordered sequence of elements involving the recognition of hazards, the measurement of impact and the comparison of the measurements. Rather, all possible combinations of elements exist in practice. Sediment quality criteria, among other approaches (see 6.3) use kinetic bioaccumulation models and bioaccumulation tests (Chapman et al., 1987)... 

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