Abstract
The artificial soil medium recommended for invertebrate toxicity studies by OECD and ISO contains sphagnum peat as an organic component. Sphagnum peat is not widely available in tropical countries especially in the Indian subcontinent. Importing of sphagnum peat is not economically feasible and also time consuming Using of native organic matter source is also much more ecologically relevant for the region. Hence, development of an alternative is needed as a replacement of sphagnum peat. As coco peat is easily available as an organic component in tropical countries, earthworm toxicity studies were conducted with coco peat to assess its suitability to be included as an alternative in the artificial soil medium. Artificial soils were prepared with 70% sand, 20% kaolin clay and 10% coco peat (COPS ) or/ sphagnum peat (SPPS). Acute and reproduction toxicity studies were conducted with the earthworm, Eisenia fetida using 2-chloroacetamide and carbendazim, respectively . Validity criteria specified by the guidelines were met in tests with either soil media. In the acute test, no significant difference was observed between the soils in terms of mortality (p > 0.05 ) based on the LC50 values for COPS and SPPS of 35.56 and 32.36 mg 2-chloroacetamide /kg dry soil, respectively. Significant effect in terms of reproduction was observed at 2.06 mg carbendazim/kg dry soil for both COPS and SPPS . The other parameters such as biomass change, mortality and food consumption of COPS and SPPS were comparable. Key words: Coco peat, shagnum peat, artificial soil, earthworm toxicity, carbendazim, 2-chloroacetamide.
Highlights
In terrestrial ecotoxicity assessment, especially with soil living organisms like earthworms, enchytraeids, and collembolans, the toxicity of a substance is strongly influenced by the medium in which the organisms are exposed
The main objective of the study was to determine the suitability of composed coco peat as an alternative to sphagnum peat in the artificial soil used for earthworm toxicity studies
Organic carbon and total organic matters were significantly higher in sphagnum peat as compared to coco peat
Summary
Especially with soil living organisms like earthworms, enchytraeids, and collembolans, the toxicity of a substance is strongly influenced by the medium (that is soil type and properties) in which the organisms are exposed. Risk assessment for chemicals in soil has to take into account soil properties. This consideration led to the conclusion that it would be preferable to standardize the soils used for determining the toxicity of chemicals to soil organisms (P Mangala et al, 2009; Gawlik, 2001). In the artificial soil (suggested by the guidelines OECD, 1984; 2004; ISO 2012a;b), sphagnum peat is a component that represent soil organic matter. Peat consisted about 5 to 10% of the total formulation. The other soil ingredients are 69 – 74% sand, 20% clay and 0 to 1% CaCO3 (to increase the pH up to 6.5)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Toxicology and Environmental Health Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
