Standardized Growth Toxicity Testing (Cu, Zn, Pb, and Pentachlorophenol) with Helix aspersa

Juvenile Helix aspersa (1 month, 1 g) were exposed for 4 weeks to food contaminated with copper, zinc, lead, and pentachlorophenol. At concentrations observed in contaminated soils, two essential metals at low levels (Cu and Zn) had a dose-dependent sublethal action on growth. Copper inhibited growth dose-dependently between 1000 and 2000 μg·g−1 (EC50=1200 μg·g−1), whereas zinc had a toxic effect from 4000 μg·g−1 (EC50=5500 μg·g−1) on. Lead, a nonessential metal, had no negative effect on growth, unlike cadmium (EC50=140 μg·g−1), as reported previously. Pentachlorophenol inhibited growth at a concentration of 500 μg·g−1 from the fourth week and 1000 μg·g−1 from the first week on. The results obtained with these key organisms in the food chain (consumers) complement those obtained with other land invertebrates (earthworms, springtails, wood-lice, etc.). The findings of the present study and those of earlier studies indicate that juvenile snails are useful organisms for testing the sublethal toxicity of chemicals acting via the food, i.e., the main route of toxicant uptake in land animals.