Heavy Metal (Copper, Lead, and Zinc) Accumulation and Excretion by the Earthworm, Dendrobaena veneta

Abstract

To obtain knowledge about heavy metal kinetics in earthworms (Dendrobaena veneta), we performed accumulation and excretion experiments under laboratory conditions using soils from a heavy metal (Cu, Pb, and Zn)‐contaminated site. To determine heavy metal accumulation rate, earthworms were exposed for 1, 2, 3, 7, 14, 28, 56, or 112 d to soil MH (Cu: 815 mg kg−1, Pb: 340 mg kg−1, and Zn: 225 mg kg−1). After exposure for 28 d to soil LB (Cu 242 mg kg−1, Pb: 109 mg kg−1, Zn 72 mg kg−1) or for 112 d to soil MH, D. veneta were transferred to uncontaminated soil and sampled after 1, 2, 3, 7, 14, 28, or 56 d to determine heavy metal excretion rates. Fourteen days after the transfer to the uncontaminated soil, some earthworms were transferred back to soil LB to determine the accumulation after a short recovery period. The Cu accumulation until Day 56 could be described by a one‐compartment model. At Day 112, however, we observed an unexpected further increase in tissue Cu concentration (CCu). We observed a significant increase in CZn, only at Day 112. Excretion of Cu could be described excellently by a two compartment model, the half‐life times being t1/2;1 ≈ 0.36 d, and t1/2;2 ≈ 37 d. Excretion of Pb could be described with a one‐compartment model. After a fast initial excretion (t1/2 ≈ 0.70 d), Pb excretion stagnated. The accumulation after a 14‐d recovery period appeared to be significantly less than the initial accumulation. The Pb accumulation appeared to be slower after recovery than before.

Uptake and elimination kinetics of metals in soil invertebrates: A review

“…Internal Zn concentrations in the earthworm Dendrobaena veneta did not differ from initial concentrations during 56 days of exposure in contaminated field soil (Marinussen et al, 1997b). Oneor two-compartment kinetics models did not fit the data.…”

“…Slow elimination rates of Cu in Marinussen et al (1997b) were explained by Cu binding to chloragosomes, cytoplasmic granules derived from lysosomes in chloragocytes of earthworms (Ireland, 1978). Chloragocytes form a diffuse layer of tissue along the dorsal blood vessel and blood sinuses in earthworms, separating the coelome from the blood.…”

Assessment and bioremediation of heavy metals from crude oil contaminated soil by earthworms

“…Some researchers has reported that bioaccumulation of heavy metals by earthworms is metal-specific (Marinussen et al, 1997), as well as earthworm species-specific (Morgan and Morgan, 1999;Hobbelen et al, 2006;Suthar et al, 2008). However, the difference in metal uptake and elimination kinetics between earthworm species is still unknown.…”

Earthworms Eisenia fetida affect the uptake of heavy metals by plants Vicia faba and Zea mays in metal-contaminated soils

“…Numerous authors have suggested that E. fetida is able to regulate Zn by binding Zn in their chloragogenous tissue (Morgan, 1981;Morgan and Morris, 1982;Morgan and Winters, 1982;Cotter-Howells et al, 2005). Since the binding of Zn to metallothioneins is reversible, it was likely that Zn-thioneins may regulate the concentrations of metal in the body tissue by allowing rapid elimination of Zn (van Gestel et al, 1993;Marinussen et al, 1997). Indeed, Zn is an essential element and its internal level is regulated by earthworms; the efficiency of Zn accumulation probably relates to a necessity for a stored pool of available Zn in anticipation of future physiological demand (Nannoni et al, 2011).…”