HP2 Global Perspectives on Soil Ecotoxicology
255 Portland Ballroom
1:20 PM - 5:20 PM, Thursday
() Application of Soil Ecotoxicology to Management of Soil Contamination in Canada.
Nason, G, Bright, D,
ABSTRACT- Like other industrialized countries, Canada has its share of contaminated land. The Canadian Council of Ministers of Environment (CCME) identified management of contaminated land as a priority in the late 1980s, and has since developed a framework and scientific tools for the assessment and remediation of contaminated land. Maintaining soil quality is a central concept in the CCME policy framework, which embodies protection of both biota and biotic processes. Protection goals are set for these at the root, or Tier 1, level of the system as described in a protocol for development of soil quality guidelines. Protection of higher animals (livestock, wildlife) is primarily based on modelled exposures from a contaminated soil source, and at higher levels of the CCME system, site-specific information can be used in concert with exposure models to drive site remediation decisions, while maintaining consistent protection goals. Soil thresholds for protection of plants and soil dwelling organisms are developed primarily through application of the soil ecotoxicology literature (ideally based on a formal appreciation of between-species sensitivity variation). CCME has worked closely with Environment Canada over the past few years to identify and confirm appropriate toxicity testing protocols and interpretation methods to support soil quality guideline development and site-specific applications. Generally, data from chronic, sub-lethal plant and invertebrate studies - particularly EC25 - are preferred. Where sufficient data exist, weight-of-evidence procedures are used to interpret multispecies sensitivity distributions in various ways that recognize a range of land uses and corresponding ecological protection expectations. Where data are insufficient to support a weight-of-evidence procedure, guidelines may be based on median effects data or other toxicological endpoints. Experience with these procedures has led to recommendations for additional toxicity testing protocols to address a broader range of organisms from non-agricultural systems as well as research and development for microbial community functional assays.
Key words: quality, benchmarks, ecotoxicology