The evaluation of soil quality requires the use of robust methods to assess biologically based indicators. Among them, enzyme activities are used for several decades, but there is a clear need to update their measurement methods for routine use, in combining feasibility, accuracy, and reliability. To this end, the platform Biochem-Env optimized a miniaturized method to measure enzyme activities in soils using colorimetric substrates in micro-well plates. The standardization of the method was carried out within the framework of ISO/TC 190/SC 4/WG 4 "Soil quality - Biological methods" workgroup, recommending an inter-laboratory evaluation for the publication of a full ISO standard. That evaluation, managed by the platform, was based on the measurement, in six soils of contrasted physicochemical properties, of the ten soil enzyme activities described in the standard. Eight laboratories were involved in the validation study. Only 2.7% of outliers were identified from the analyses of the whole dataset. The repeatability and reproducibility of the method were determined by computing, respectively, the intra-laboratory (CVr,) and inter-laboratory (CVR) coefficients of variation for each soil and enzyme. The mean CVr ranged from 4.5% (unbuffered phosphatase) to 9.9% (α-glucosidase), illustrating a reduced variability of enzyme activities within laboratories. The mean CVR ranged from 13.8% (alkaline phosphatase) to 30.9% (unbuffered phosphatase). Despite this large CVR noticed for unbuffered phosphatase, the method was repeatable, reproducible, and sensitive. It also proved to be applicable for measuring enzyme activities in different types of soils. These results have been found successful by ISO/TC 190/SC4 and resulted in the publication of ISO 20130:2018 standard.

• Klíčová slova
• Microplate test, Soil enzyme activities, Soil functions, Soil quality, Standardization, Inter-laboratory trial,
• MeSH
• alfa-glukosidasy MeSH
• fosfatasy MeSH
• kolorimetrie * metody   MeSH
• látky znečišťující půdu analýza   MeSH
• půda * chemie   MeSH
• reprodukovatelnost výsledků MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-glukosidasy MeSH
• fosfatasy MeSH
• látky znečišťující půdu MeSH
• půda * MeSH

Environmental risk assessment of contaminated soils requires bioindicators that allow the assessment of bioavailability and toxicity of chemicals. Although many bioassays can determine the ecotoxicity of soil samples in the laboratory, few are available and standardized for on-site application. Bioassays based on specific threshold values that assess the in situ and ex situ bioavailability and risk of metal(loid)s and polycyclic aromatic hydrocarbons (PAHs) in soils to the land snail Cantareus aspersus have never been simultaneously applied to the same soils. The aims of this study were to compare the results provided by in situ and ex situ bioassays and to determine their respective importance for environmental risk assessment. The feasibility and reproducibility of the in situ bioassay were assessed using an international ring test. This study used five plots located at a former industrial site and six laboratories participated in the ring test. The results revealed the impact of environmental parameters on the bioavailability of metal(loid)s and PAHs to snails exposed in the field to structured soils and vegetation compared to those exposed under laboratory conditions to soil collected from the same field site (excavated soils). The risk coefficients were generally higher ex situ than in situ, with some exceptions (mainly due to Cd and Mo), which might be explained by the in situ contribution of plants and humus layer as sources of exposure of snails to contaminants and by climatic parameters. The ring test showed good agreement among laboratories, which determined the same levels of risk in most of the plots. Comparison of the bioavailability to land snails and the subsequent risk estimated in situ or ex situ highlighted the complementarity between both approaches in the environmental risk assessment of contaminated soils, namely, to guide decisions on the fate and future use of the sites (e.g., excavation, embankments, and land restoration). Integr Environ Assess Manag 2022;18:539-554. © 2021 SETAC.

• Klíčová slova
• Bioaccumulation, Biomonitoring, Land snail, Metals, Polycyclic aromatic hydrocarbons,
• MeSH
• biotest MeSH
• hodnocení rizik MeSH
• látky znečišťující půdu * analýza   toxicita   MeSH
• monitorování životního prostředí MeSH
• polycyklické aromatické uhlovodíky * analýza   toxicita   MeSH
• půda MeSH
• reprodukovatelnost výsledků MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• látky znečišťující půdu * MeSH
• polycyklické aromatické uhlovodíky * MeSH
• půda MeSH