Snail survival as bioindicator of cadmium contaminated soils under semi-realistic field conditions

Abstract

Juvenile brown garden snails (Helix aspersa Müller) were exposed to Cd-contaminated soils for 60 days
under semi-realistic field conditions. The soils were contaminated with increasing concentrations of cadmium
chloride (0–2900 mg kg-1 Cd2+/solution CdCl2). The snails were housed in terrariums and were fed
exclusively with nettle leaves. The experiments were carried out in Timisoara on 1000 snails.The survival
rates differed significantly for different Cd treatments. Only higher cadmium concentrations (> 1000 mg kg-1
Cd2+/solution CdCl2) had a significant influence on survival curves of snails exposed to Cd-contaminated
soils. The maximal death rate reached 81.00±9.9% for snails exposed to soils contaminated with 2900 mg kg1
Cd /solution CdCl2. We found dose-dependent survival rates, whereas the half maximal effective
concentration was 1365 mg kg-1 Cd2+/solution CdCl2. Our results suggested that longer-term studies are
required for assessing the real potential of snail survival rate as bioindicator of Cd-contaminated soils in field conditions.