Soil quality of two sites in Northeast Algeria: Use of a bioindicator species of soil pollution [Qualité des sols dans deux sites du Nord-Est Algérien: Utilisation d'une espèce bioindicatrice de la pollution des sols]

Previous work has shown that metal pollution is prominent in the region of annaba. soil contamination results from the contribution of pesticides and leaching generated by the steel complex,arcelor mittal metal dust. this study is part of a biomonitoring program on quality of terrestrial ecosystems using helix aperta (born 1778) as a bioindicator and assess the quality of soils in two sites: el hadjar,located near the arcelormittal manufactory,and el kala situated in the national park away from all sources of pollution. an assay of acetylcholinesterase (ache,biomarker of neurotoxicity) and glutathione s-transferase (biomarker of oxidative stress) activities were performed on animals collected from the two studied sites. in a second series of experiment,we tested under laboratory conditions the response of this bioindicator species to a trade formulation of a neonicotinoid insecticide (actara,syngenta®),widely used in several crops in algeria. the insecticide was administered topically at several concentrations (2000,2500,3000 mg a.i/l). the results show an inhibition in ache activities and an induction in gst activities in the site of el hadjar compared to el kala site. bioassays of contamination of juveniles of this species show that actara exhibits toxicity with a dose-response relationship. the different parameters of lethality were determined. thus,the juveniles from el kala are significantly more sensitive than those of el hadjar.(ld50 = 4298 mg a.i/l in individuals from el hadjar,ld50 = 3565 mg a.i/l in individuals from el kala).