Poll Res. 33 (4) : 201-206 (2014) Copyright © EM International ISSN 0257–8050 Article-35 *Corresponding author : Prof. V.C. Joy, E-mail: vcjoy11@visva-bharati.ac.in . SHORT-TERM OXIDATIVE STRESS RESPONSES IN CYPHODERUS JAVANUS BORNER (COLLEMBOLA), AS BIOMARKERS OF HEAVY METAL POLLUTION IN LATERITIC SOIL ATREYEE SAHANA 1 , SOUMIK AGARWAL 2 , SHELLEY BHATTACHARYA 2 AND JOY VADAKEPURAM CHACKO 1* 1 Soil Ecology Laboratory, 2 Environmental Toxicology Laboratory Department of Zoology (Centre for Advanced Studies), Visva-Bharati University, Santiniketan 731 235, India (Received 12 March, 2014; accepted 10 May, 2014) ABSTRACT The scope of ecotoxicological evaluation of heavy metal pollution in soil was tested from the oxidative stress responses in a detritivore microarthropod species Cyphoderus javanus Borner (Collembola: Insecta) exposed to sub-lethal levels of cadmium and lead treated lateritic soil in microcosms. Chronic toxicity of cadmium was higher than lead on life history parameters of 10- day-old stock of C. javanus (mortality increased by 62% and 27%, moulting declined by 69% and 45%, and fecundity decreased by 97% and 41%, respectively, over the controls, at 200 mg cadmium sulphate / lead acetate kg -1 soil, in 16 days). In contrast, oxidative stress effects were evident within 7 days for both metals at 200 mg kg -1 lateritic soil or river sand. Levels of thio-barbituric acid reactive substances and hydrogen peroxide increased in whole body homogenate, but glutathione content and glutathione-S-transferase activity decreased. Similar trends of stress in soil and sand suggested that toxicity was produced by the exposed metal content in the matrix. Therefore, short- term oxidative stress responses in C. javanus are potential biomarkers, and a new approach for monitoring heavy metal pollution in soil. KEY WORDS : Collembola, Heavy metal toxicity, Lipid peroxidation, Antioxidant enzymes PR-P-789 INTRODUCTION Heavy metals that are released into the environment through a wide range of anthropogenic waste materials are known to produce ecological ill effects and health hazards. Watson et al. (1976) showed that emissions of heavy metals from a lead mining- smelting complex affected the litter-arthropod food chain, and rates of litter decomposition and nutrient release in forest. Croplands are also contaminated with heavy metals from compost, coal fly ash, etc., that are used for nutrient supplementation and soil conditioning. The toxicity depends on absorption, concentration and persistence of the metal that reacts with endogenous target molecules, or produce structural and functional changes in biological system. For example, redox inactive metals like cadmium, arsenic, lead are deleterious to the biota, cause toxicity via production of ROS and free radicals, bonding to sulfhydryl group of protein and depletion of glutathione (Pain, 1995, Stohs et al., 2001, Jomova and Valko, 2011). The antioxidant defence system in insects is strategically similar to that in vertebrates (Pardini, 1995). Both enzymatic and non-enzymatic antioxidant defence against heavy metals were recorded in the gastropod, Achatina fulica (Chandran et al ., 2005); in grasshopper, Oxya chinensis (Lijun et al., 2005); and in earthworm, Lampito mauritii (Maity et al., 2008). Among soil fauna, microarthropods like Collembola are sensitive indicators of edaphic perturbations (Van Straalen, 1998). There are reports on the impact of heavy metals on Collembola; however, most studies are from the European soil conditions (Xu et