Skip to main content

Chronic and reproductive toxicity of cadmium, zinc, and lead in binary and tertiary mixtures to the earthworm (Eisenia fetida)

Abstract

Purpose

The presence of one metal can alter the toxicity of another metal by having an additive, synergistic, or antagonistic impact. Mixed metal pollution has clear ecological consequences. The importance of use of earthworms for ecological health monitoring is recognized widely. This study investigated the effect of binary and tertiary metal mixtures on the toxicity, bioaccumulation, and reproduction of the Eisenia fetida in different South Australian soils.

Materials and methods

The end points used in this 56-day reproduction study were avoidance behavior, worm mortality, weight loss, reproduction, and metal (Cd, Zn, and Pb) bioaccumulation. The three soils (acidic, neutral, and alkaline) were spiked with selected binary and tertiary concentration mixtures that considered the soil quality guideline values, EC50 and LC50 values for Cd, Zn, and Pb obtained from the previous single metal earthworm experiments done by the authors.

Results and discussion

In acidic soil, Zn and Cd constituted the most toxic metal combination to earthworms. However, in contrast to this observation, the same metal combination was the least toxic one to earthworms in neutral and alkaline soils. For Zn and Pb spiked soils, relationships between soil and internal metal concentrations were found with R 2 = 0.63, r = 0.8, and R 2 = 0.94, p < 0.01, respectively, for Zn and Pb. This study indicates that earthworms have high tendency to bioaccumulate heavy metals in their tissues and hence serves as ecological indicators of soil heavy metal contamination. The highest bioaccumulation factor (0–9) was evident for Cd in contaminated soils. This study demonstrated the role of soil edaphic factors and metal-metal interactions in the toxicity of metal mixtures to E. fetida.

Conclusions

In Zn and Pb binary mixture spiked acidic soil, mortality of 60% was recorded even when the Pb and Zn concentrations were below the Canada and Dutch EIL (ecological investigational levels) values. This indicates the current guideline values are not safe for mixed metal toxicity. Therefore, care must be taken when predicting metal toxicities in mixed metal contaminated soils.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

References

Download references

Acknowledgements

All the authors would like to thank C. Danidu Kudagamage for helping with the earthworm experiments.

Funding

This study was funded through a CRCCARE postgraduate scholarship.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to M. A. Ayanka Wijayawardena.

Additional information

Responsible editor: Sung-Eun Lee

Electronic supplementary material

ESM 1

(DOCX 18 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Ayanka Wijayawardena, M.A., Megharaj, M., Naidu, R. et al. Chronic and reproductive toxicity of cadmium, zinc, and lead in binary and tertiary mixtures to the earthworm (Eisenia fetida). J Soils Sediments 18, 1602–1609 (2018). https://doi.org/10.1007/s11368-017-1877-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11368-017-1877-z

Keywords

  • Bioaccumulation
  • Earthworm
  • Metal mixtures
  • Soil guideline value
  • Toxicity