Transfer of Cd, Cu, Ni, Pb, and Zn in a soil‐plant‐invertebrate food chain: A microcosm study

Abstract

The transfer of Cd, Cu, Ni, Pb, and Zn was evaluated in a soil-plant (lettuce, Lactuca sativa)-invertebrate (snail, Helix aspersa) food chain during a microcosm experiment. Two agricultural soils, polluted and unpolluted, were studied. Lettuce was cultivated for eight weeks before introduction of snails into the microcosms (M-snails). In a parallel experiment, snails were exposed to lettuce only (i.e., without soil) in simpler exposure devices called containers (C-snails). Snail exposure duration was eight weeks for both M- and C-snails. No effects on snail survival were found. Both M- and C-snails exposed to polluted soil showed a growth reduction, but only after two weeks of exposure. Time-dependent accumulation in M-snails exposed to the polluted environment showed a regular increase of Cd and Zn concentrations over time and a rapid increase of Pb concentrations within the first two weeks, which then remained stable. Copper and Ni concentrations did not increase during any of the experiments. Concentrations in M- and C-snails were compared to estimate the relative contribution of soil and plant to the total bioaccumulation. The results suggest that the soil contribution may be higher than 80% for Pb, from 30 to 60% for Zn, and from 2 to 40% for Cd.

Nutritional composition of aquatic species in Laotian rice field ecosystems

“…Iron content in big apple snail (102 mg/100 g) and golden apple snail (48 mg/100 g) are far higher than the results presented in James (2006) for molluscs (7-26.6 mg/100 g) and CFCD (2002) for rice paddy field snail (19.7 mg/100 g). As snails ingest sludge from the surrounding paddy field (Scheifler et al, 2006), washing was a determining process in minimizing mineral content before the snails were analyzed. Thus there is a possibility that the high Table 6 Contents of calcium, zinc and iron in the analyzed fish, other aquatic animals and fermented fish a (mg/100 g samples).…”

“…Big apple snails contained the highest level (12 mg/100 g) and padek from Savannakhet market contain the lowest (0.35 mg/ 100 g). This may be due to the aforementioned ability of the snails to ingest sludge from the surrounding paddy field (Scheifler et al, 2006). The previously mentioned washing procedure in the laboratory may also influence the measurement of zinc content.…”

Effects of sewage sludge amendment on snail growth and trace metal transfer in the soil-plant-snail food chain

“…Therefore, the Cu, Zn, and Cd assimilation in snails was mainly the result of transfer from amended lettuce leaves to snails. The contribution of soil to Pb assimilation in snails has been reported to be higher than 80 % (Scheifler et al 2006). Similarly, a recent study revealed that 89.9 % of assimilated Pb was transferred directly via the soil (Pauget 2012).…”

Investigations of responses to metal pollution in land snail populations (Cantareus aspersus and Cepaea nemoralis) from a smelter-impacted area

“…The microcosms were placed on the ground over the natural vegetation and 10 mm mesh stainless steel netting was securely fitted over the top of the microcosm, avoiding the escape of the snails and predation. Therefore, the snails were able to feed on soil, litter and vegetation and were exposed via dermal, respiratory and digestive routes (Coeurdassier et al 2002;Fritsch et al 2008;Gimbert et al 2008b;Scheifler et al 2006). Microcosms were placed side by side (less than 1 meter apart) and animals of each group (C. aspersus ME or BE and C. nemoralis ME or BE) were randomly assigned to microcosms.…”

“…Snail faeces also clearly confirmed that the snails feed on the vegetation in the microcosms (personal observation). Snails can be exposed to pollutants via several routes: oral, dermal and respiratory (Coeurdassier et al 2002;Fritsch et al 2008;Gomot-de Vaufleury and Pihan 2000;Regoli et al 2006;Scheifler et al 2006). Concerning oral exposure, they can be exposed via trophic pathway, by eating soil, litter and vegetation.…”