Stanek K, Drobne D, Trebše P
[ pdf ] [ site ] Chemosphere, 2006

In parallel laboratory experiments, we determined the effect of a typical representative of organophosphorous pesticides, diazinon, on AChE activity, lipid, protein and glycogen content, weight change, feeding activity and mortality of juvenile and adult terrestrial isopods Porcellio scaber (Isopoda, Crustacea). Organophosphorous pesticides (OP) are among the most extensively used pesticides, which have replaced organochlorine pesticides. OPs inhibit the enzyme acetylcholinesterase (AChE), resulting in neurotoxicity. They have more widespread effects on non-target organisms than do organochlorine pesticides. The aim of this study was to link effect of diazinon on target enzyme to energy reserves and to integrated biomarker responses in juvenile and adult P. scaber. The non-observed effect concentration (NOEC) for AChE activity after diazinon exposure in two weeks toxicity study with isopods was below 5 μg/g diazinon. There was a good agreement between concentrations at which AChE and survival were affected (10 μg/g diazinon in juveniles, 100 μg/g diazinon in adults). We revealed a link among AChE activity, protein content and mortality. Glycogen and lipid content, feeding activity and weight change were not affected in two weeks diazinon exposure up to 100 μg/g diazinon. Juveniles were affected at concentrations that were an order of magnitude lower than those provoking similar effects on adults. Recommendations are made for future toxicity studies with terrestrial isopods.