Combined effects of copper, desiccation, and frost on the viability of earthworm cocoons
- National Environmental Research Inst., Silkeborg (Denmark). Dept. of Terrestrial Ecology
- National Environmental Research Inst., Roskilde (Denmark). Dept. of Marine Ecology and Microbiology
The effects of heavy metal pollution on earthworms have been extensively studied, but no studies have examined how earthworms react if they are simultaneously exposed to metal pollution and climatic stress. This question has been addressed in a laboratory study where cocoons of Aporrectodea caliginosa and Dendrobaena octaedra were initially exposed to copper in aqueous solutions of copper chloride and thereafter exposed to realistic degrees of either desiccation or frost. Earthworm embryos absorbed copper in amounts comparable to concentrations found in various tissues of earthworms from metal-polluted soils. Desiccation and copper exposure in combination had synergistic effects on survival rates for both species. For example, at full saturation, the NOEC (the highest tested concentration with no statistically significant effect) for copper of A. caliginosa was 12 mg/L, whereas at 97% relative humidity it was only 6 mg/L. Frost and copper exposure in combination also showed synergistic effects in some experiments. No cocoons of A. caliginosa exposed to 20 mg copper/L were viable after exposure to {minus}3 C but at 0 C viability was as high as 95%. The same tendency was seen in D. octaedra but not as clearly as in A/. caliginosa. A change of the environmental conditions (moisture, temperature) to increasing severity caused a shift in the statistically derived NOEC toward lower critical values of copper. The involvement of combination effects in ecotoxicological tests could therefore improve risk assessment of soil-polluting compounds.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 675489
- Journal Information:
- Environmental Toxicology and Chemistry, Vol. 17, Issue 1; Other Information: PBD: Jan 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ecotoxicological and analytical assessment of hydrocarbon-contaminated soils and application to ecological risk assessment
Development of a standardized reproduction toxicity test with the earthworm species Eisenia fetida andrei using copper, pentachlorophenol and 2,4-dichloroaniline