Toxicity of chemical-warfare agent HD to Folsomia candida in different soil types Carlton T. Phillips a, *, Roman G. Kuperman b , Ronald T. Checkai a a US Army Edgewood Chemical Biological Center, AMSSB-RRT-BE, E5641, 5183 Blackhawk Road, Aberdeen Proving Ground, MD 21010-5424, USA b GEO-CENTERS, INC., Gunpowder Branch, P.O. Box 68,Aberdeen Proving Ground, MD 21010-0068, USA Received 14 August 2000; accepted 30 May 2001 Abstract We investigated the ecotoxicity of the chemical-warfare agent (CWA) HD (Mustard) using Collembola reproduction test with numbers of adults and juveniles as measurement endpoints. Toxicity tests were conducted using soils with contrasting parameters to investigate the effects of soil properties on chemical toxicity. These included standard artificial soil (SAS; 10% OM; 6 pH), O’Neill-Hall sandy loam (OHSL; natural soil with 4.3% OM; 5.1 pH), and Sassafras sandy loam (SSL; natural soil with 2% OM; 4.9 pH). Soils were individually spiked with HD concentrations ranging from 1 to 125 mg kg –1 . Lowest observed effect concentrations (LOECs) for adult mortality were 25, 50, and 6.97 mg kg –1 for SAS, OHSL, and SSL, respectively. The LOECs for reproduction were 6.97, 6.25, and 1.9 mg kg –1 for SAS, OHSL, and SSL, respectively. HD toxicity to both adults and juveniles was greater in SSL. These results show that soil toxicity testing should not rely solely on the adult acute endpoints using artificial soils, but should include assays with reproductive endpoints using natural soils with varying physical and chemical parameters to adequately assess toxicity to test species. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. Keywords: Collembola; Soil toxicity test; HD; Adult mortality; Reproductive endpoint 1. Introduction Soil toxicity tests, used to determine the ecotoxicological effects contaminants have on soil fauna, have typically been acute tests focusing on the chemical effects on adult mortality [14]. Chemicals may influence populations of soil invertebrates in different ways, including direct acute tox- icity and chronic toxicity such as effects on growth and/or reproduction. The collembolan reproduction test can be used to determine the effect pollutants have on the most vulnerable developmental stage of the test organisms (juve- nile and adult survival, reproductive success). The Collem- bola are the most studied group of soil microarthropods. Several species have been used for soil toxicity testing [1,12] and well-developed methods have been published for Isotoma tigrina [5,15] and Folsomia fimetaria [6,11,15]. The species used most often in ecotoxicological investiga- tions is Folsomia candida (Willem). The test with F. can- dida was designed to investigate the effects of chemicals on adult and juvenile survival, and reproduction [13]. This parthenogenetic species is sensitive to a wide range of disturbances, which can signal changes in the soil commu- nity. This, in part, is attributed to the fact that F. candida belongs to the fungal energy channel (all food chains originating from fungi) which is more sensitive to distur- bances than are the bacterial or root energy channels [8]. The folsomid test has the potential to adequately determine the effects soil contamination has on the structure of soil microarthropod community. This toxicity test was standard- ized by ISO in 1998 [4]. We used the collembolan reproduction test with F. can- dida to determine ecotoxicological effects of chemical- * Corresponding author. Fax: +1-410-436-4846. E-mail address: ctphilli@sbccom.apgea.army.mil (C.T. Phillips). European Journal of Soil Biology 38 (2002) 281-285 www.elsevier.com/locate/ejsobi © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. PII: S 1 1 6 4 - 5 5 6 3 ( 0 2 ) 0 1 1 6 0 - 3