Do aquatic effects or human health end points govern the development of sediment‐quality criteria for nonionic organic chemicals?

Abstract

The equilibrium partitioning theory may be used to describe the partitioning of nonionic organic chemicals between water, sediment, and aquatic biota. This paradigm was employed to compare the relative magnitudes of organic carbon‐normalized sediment‐quality criteria that are intended to protect either benthic organisms from the direct toxic effects of sediment‐associated chemicals or humans from the indirect health effects posed by the ingestion of contaminated aquatic animals. Comparison of calculated sediment‐quality criteria for a variety of hydrophobic chemicals suggests that human health‐based end points often result in more restrictive criteria than aquatic effects‐based values. Review of published field data indicates that the equilibrium partitioning paradigm may, depending on contaminant class, either over‐ or underestimate the extent to which sediment associated contaminations are bioaccumulated. Despite the limitations of adopting this simple theory for criteria development, calculations reveal that regulatory decisions involving sediments contaminated with such chemicals may be dictated by human health concerns if current risk assessment methodologies are applied.

Bioaccumulation of polychlorinated biphenyls from sediments to aquatic insects and tree swallow eggs and nestlings in Saginaw Bay, Michigan, USA

“…The BSAF has been proposed as an empirical relationship to predict the lipid‐normalized concentrations of residues from the TOC‐normalized concentration of the same residue in sediments [13,20,49]. The BSAF approach has been proposed for use as a regulatory tool in risk assessment methodologies involving contaminated sediments [13,50] and in conjunction with an appropriate reference dose to calculate SQC that are protective of wildlife [13].…”

Dioxin transfer from sediment to the infaunal surface deposit‐feeding polychaete Perinereis nuntia in a laboratory‐rearing experiment

“…The BSAF was defined as the ratio of the concentration in polychaetes (normalized to lipid wt) to the concentration in sediment (normalized to organic carbon wt) [18]. The BSAFs did not include material associated with sediment in the gut (BSAF (ÀSed) ) and were calculated using the concentrations at the end of the uptake phase of the experiment as follows:…”

Technical basis for narcotic chemicals and polycyclic aromatic hydrocarbon criteria. I. Water and tissue

“…There may be a problem with a direct application of these concentrations to observed body burdens in organisms that can metabolize specific narcotic chemicals such as PAHs. In analyses of the ratio of nonionic chemicals in organism lipid and sediment organic carbon, the PAHs are found to have significantly lower ratios than other, presumably non metabolized, chemicals [24,25]. Clearly, if metabolism is important, then measuring the body burden of only the parent compounds would underestimate the toxicity of these chemicals.…”