BS ISO 23266:2020 pdf download – Soil quality – Test for measuring the inhibition of reproduction in oribatid mites (Oppia nitens) exposed to contaminants in soil
1 Scope
This document specifies one of the methods for evaluating the habitat function of soils and determining effects of soil contaminants and individual chemical substances on the reproduction of the oribatid mite Oppia nitens by dermal and alimentary uptake. This chronic (28-day) test is applicable to soils and soil materials of unknown quality (e.g., contaminated sites, amended soils, soils after remediation, agricultural or other sites under concern and waste materials). This method is not intended to replace the earthworm or Collembola tests since it represents another taxonomic group (= mites; i.e., arachnids), nor the predatory mite test since this species represents a different trophic level and ecological niche. Effects of substances are assessed using standard soil, preferably a defined artificial soil substrate. For contaminated soils, the effects are determined in the test soil and in a control soil. According to the objective of the study, the control and dilution substrate (dilution series of contaminated soil) should be either an uncontaminated soil with similar properties to the soil sample to be tested (reference soil) or a standard soil (e.g., artificial soil). Information is provided on how to use this method for testing substances under temperate conditions. This document is not applicable to substances for which the air/soil partition coefficient is greater than 1, or to substances with vapour pressure exceeding 300 Pa at 25 °C. NOTE The stability of the test substance cannot be assured over the test period. No provision is made in the test method for monitoring the persistence of the substance under test.
4 Principle
The effects on reproduction of adult, laboratory-cultured mites, Oppia nitens, exposed to the test soil are compared to those observed for organisms in control soil. If appropriate, effects based on exposure to a test mixture of contaminated soil and control soil, or a range of concentrations of a test substance mixed into control soil, are determined. Test mixtures are prepared at the start of the test and are not renewed during the test period. The test is started with 15 adult mites from age-synchronized cultures (aged 8 to 10 d after ecdysis (i.e., moult) to adult form) per test vessel. The test is performed in 30 mL glass vessels with a wet- weight equivalent to a volume of ~20 mL of soil, and a minimum of five replicates are prepared for each treatment. The test runs for 28 d at (20 ± 2) °C by which time offspring (F 1 ) have emerged from eggs laid by the adults and the number of offspring produced is determined. Survival of the adults is also determined at the end of the test. The results obtained from the tests are compared with a control or, where a serial dilution design is used, to determine the concentration resulting in x % reduction of juveniles produced compared to the control (ECx, 28 d), depending on the experimental design. An estimate of the test concentration resulting in x % mortality (LCx, 28 d) is an optional test endpoint. If a multi-concentration hypothesis test design is used, the reproductive output of the mites exposed to the test mixtures is compared to that of the controls in order to determine the concentration which causes no effects on mortality and reproduction (NOEC).