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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Administrative data

Endpoint:
toxicity to soil macroorganisms except arthropods: long-term
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Already evaluated by the Competent Authorities for Biocides and Existing Substance Regulations.

Data source

Reference
Reference Type:
publication
Title:
Effects of metals and metal mixtures on survival and cocoon production of the earthworm Aporrectodea caliginosa
Author:
Khalil, M.A. et al.
Year:
1996
Bibliographic source:
Pedobiologia 40, 548-556.

Materials and methods

Principles of method if other than guideline:
Earthworms were exposed to several copper concentrations in a natural soil. Mortality and cocoon production were measured over 56 days

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test organisms

Test organisms (species):
Aporrectodea caliginosa

Study design

Study type:
laboratory study
Substrate type:
natural soil

Results and discussion

Effect concentrations
Duration:
56 d
Dose descriptor:
NOEC
Effect conc.:
70 mg/kg soil dw
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
element
Basis for effect:
reproduction
Remarks:
(No bioavailability correction possible as CEC is not given or can not be derived.)
Remarks on result:
other: No bioavailability correction possible as CEC is not given or can not be derived.

Any other information on results incl. tables

see Executive summary

Applicant's summary and conclusion

Conclusions:
Reliability: high quality NOEC value is 70 mg/kg (reproduction).
No bioavailability correction possible as CEC is not given or can not be derived.
Executive summary:

The capacity to reproduce is an essential factor fort he long-term survival of populations at the basis of the food web. Ecological effects of soil pollutants may be assessed in terms of exposure levels that reduce reproduction, relative to survival. In this study, the earthworm Aporrectodea caliginosa (Annelida, Oligochaeta) was exposed to cadmium, copper and zinc in a natural soil. Each metal was mixed into the soil, as a sulphate salt, in a different series of concentrations. Mortality and cocoon production were measured over 56 days to determine LC50, EC50, and EC10values for each metal. EC50and EC10values were determined following a loglogistic curve fitting of cocoon production versus exposure concentration. The ratio between the LC50and the EC10for effects on reproduction (sublethal sensitivity index, SSI), was different for each metal. The ratio was greatest for cadmium (a factor of 300) and smallest for zinc and copper (a factor of 6 to 10). Based on the single metal EC50s a mixture of three metals was prepared and effects on cocoon production were assessed. The EC50of the mixture was 1.4 toxic units and this value differed significantly from 1.It may be concluded that 1) SSI is highly metal- specific, and 2) the three metals, cadmium, copper, and zinc, in the concentration levels tested, have an antagonistic action on each other in their effects on cocoon production of  Aporrectodea caliginosa.