Analysis of worldwide regulatory guidance for surface soil contamination

Abstract

Regulations are emerging worldwide to address surface soil contamination. Many of these use regulatory guidance values (RGVs) to specify concentrations above which action is required. However, because so many independent jurisdictions develop these values, the results are highly variable. Recent studies have demonstrated that the RGVs used by US states vary by several orders of magnitude. This manuscript presents results from an effort that identified 62 surface soil RGV datasets containing 3574 values from 31 other nations and compiled them into a database titled International Surface Soil Regulatory Guidance Values (IS2RGV). Analysis indicates that there are also orders of magnitude variability in the RGVs used worldwide, and that this variability has much in common with US state RGV variability. Results are presented for the 30 most frequently regulated organic, 20 most frequently regulated inorganic, and all regulated element contaminants. Trichloroethylene, cyanide, and mercury are used to illustrate how worldwide RGV variability compares with that of US states, and how data may be commingled to help identify emerging consensuses.