Overview - ISO 10872:2020 (Water and soil quality, C. elegans test)
ISO 10872:2020 specifies a standardized bioassay to determine the toxic effect of environmental samples on the nematode Caenorhabditis elegans. The method assesses impacts on growth, fertility and reproduction and applies to whole freshwater sediments (maximum salinity 5 g/l), soils, wastes and to aqueous fractions derived from them (pore water, elutriates, aqueous extracts). The test is designed to measure effects of both dissolved and particle‑bound contaminants and is intended for routine ecotoxicology and sediment/soil quality assessment.
Key topics and technical requirements
- Test organism and exposure: Juvenile C. elegans are exposed to test material for a 96-hour period; endpoints include growth, fertility and reproduction compared to appropriate controls.
- Sample scope: Whole freshwater sediment (≤5 g/l salinity), soil, waste, pore water, elutriates, aqueous extracts.
- Controls and reference: Use of aqueous, sediment or soil controls; inclusion of reference substances and blank replicates to verify test performance.
- Reagents and culture media: Standardized media and reagents are specified (e.g., Nematode Growth Medium (NGM) agar, LB medium, cholesterol and defined stock solutions) to ensure reproducible cultivation of C. elegans and food bacteria (Escherichia coli).
- Procedures and measurements: Detailed steps for preparation of test material, nematode separation, measurements, recovery calculations, and statistical assessment of percent inhibition. The document includes validity criteria and reporting requirements.
- Supporting annexes: Guidance on maximal water holding capacity (WHC), photographic identification of adult worms, micropipette methods and performance data.
Applications and who should use it
- Environmental and ecotoxicology laboratories performing sediment toxicity tests, soil contamination assessments and waste impact studies.
- Regulatory agencies and consulting firms evaluating remediation effectiveness, monitoring contaminated sites, or deriving environmental quality criteria.
- Researchers using bioindicators to screen for sublethal effects of contaminants (growth, fertility, reproduction) and to link chemical analyses with biological responses.
Related standards and references
- Normative sampling and supporting standards cited include ISO 5667-16 (sampling guidance for biotesting) and ISO 7027-2 (turbidity assessment).
- ISO 10872:2020 complements other water and soil quality standards used in environmental monitoring and ecotoxicological method suites.
Keywords: ISO 10872:2020, water and soil quality, Caenorhabditis elegans, sediment toxicity, soil toxicity, pore water, elutriate, ecotoxicology, growth fertility reproduction.