Appropriate applications of sediment quality values for metals and metalloids

Globally, sediment quality values (SQVs) for metals and metalloids vary over several orders of magnitude and can be below background. Regional SQVs can be useful as an initial step in a tiered sediment hazard/risk assessment approach such as an ecological risk assessment (ERA). Further tiers are often needed to take into account site-specific data including background concentrations, factors influencing bioavailability, and essentiality. Principles of sediment assessment for metals and metalloids are proposed.