Development of a microbial test suite and data integration method for assessing microbial health of contaminated soil.

There is no standard methodology or guideline for assessing soil microbial health for the purposes of contaminant risk assessments. Here we propose a laboratory-based test suite and novel data integration method for evaluating soil microbial health using site-specific contaminated and reference soil. The test suite encompasses experiments for evaluating microbial biomass, activity, and diversity. The results from the tests are then integrated so that a Soil Microbial Health Score (SMHS) may be assigned. This test suite and data integration method was tested on soils from 3 different contaminated sites in Canada. The soil microbial health of a petroleum hydrocarbon (PHC) contaminated site was found to be 'Mildly Impacted' and 'Moderately Impacted' for two soil horizons at a boreal forest site. The soil microbial health of the mixed metal/PHC and mixed metal sites were both found to be 'Not Impacted'. Continued use of this test suite and data integration method will help create guidelines for assessing soil microbial health in ecological risk assessments.