Registration Dossier

Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

Currently viewing:

Administrative data

Endpoint:
toxicity to soil macroorganisms except arthropods: long-term
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction)
Deviations:
no
Principles of method if other than guideline:
not applicable
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): CoCl2.6H2O
- source: VVWR, Belgium
- Other: No other parameters reported
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
not applicable

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
To confirm the nominal cobalt concentrations in the soil, soils were digested in hot acid (HCI:HN03, 1:5 v/v, microwave heating)

Test substrate

Vehicle:
no
Details on preparation and application of test substrate:
All the soils were thoroughly mixed with concentrations of CoCL2.6H2O and moisture content was between 50 and 60% of water holding capacity (WHC). After spiking, samples were allowed to equilibrate for one week under the same conditions as those used for the toxicity tests.

Test organisms

Test organisms (species):
Eisenia fetida
Animal group:
annelids
Details on test organisms:
TEST ORGANISM
- Common name: earthworm
- Source: Blades Biological (Cowden, UK)
- Age at test initiation (mean and range, SD): adult with fully developed clitellum
- Weight at test initiation (mean and range, SD): 400-700mg ww

ACCLIMATION
not reported

Study design

Study type:
laboratory study
Substrate type:
natural soil
Limit test:
no
Total exposure duration:
28 d
Post exposure observation period:
the number of worms and cocoons was determined after washing the soil through a 1 mm sieve

Test conditions

Test temperature:
20 ± 1°C
pH:
4.3-7.5
Moisture:
50-60% of water holding capacity
Details on test conditions:
10 adult worms with a fully developed clitellum, were exposed to test jar containing 500g soils (wet weight). At the start of the test, 2 % (dry weight) finely ground cow dung was supplied. At the end of the tests (day 28), the number of worms and cocoons was determined after washing the soil through a 1 nun sieve. During exposure, all test vessels were kept at 20 ± 1 DC and a lightdark cycle of 16:8 at 400 - 800 lux. Soil moisture content (50 - 60 WHC) was adjusted twice a week by replenishing weight loss with the appropriate amount of deionised water. four to five replicates. Test jars were monitored daily to visually assess possible behavioural changes of the organisms.

TEST SYSTEM
- Test container (material, size): jar
- Amount of soil or substrate: 500 g ww
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
The soils tested were 10 natural soils exhibiting large variance in soil characteristics. see table 1 below.

OTHER TEST CONDITIONS
- Photoperiod: 16/8 light/dark
- Light intensity: 400-800 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : reproduction

VEHICLE CONTROL PERFORMED: no

TEST CONCENTRATIONS
The concentrations of cobalt (added as CoCh.6H20 , VWR, Belgium) were chosen in logarithmic series. The ranges of concentrations were selected based on (1) results of cobalt toxicity in two artificial soils OECD and LUF A.2 to E. albidus (Lock et aI. , 2006) and of the range finding tests 6 with three soils (Kasterlee, bcuven and Brecy) using E. fetida; ana \2) the linear relationship between metal toxicity (expressed as ECso) and the Cation Exchange Capacity (CEC) of the soils observed in previous studies (Lock et ai., 2003 ; Van Eeckhout et ai., 2005).
Nominal and measured concentrations:
not reported
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
28 d
Dose descriptor:
EC10
Effect conc.:
56 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co in Athens soil
Basis for effect:
reproduction
Remarks on result:
other: 95% CL: 27-113
Duration:
28 d
Dose descriptor:
EC10
Effect conc.:
57 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co in Jyndevad soil
Basis for effect:
reproduction
Remarks on result:
other: 95% CL: 21.9-148
Duration:
28 d
Dose descriptor:
EC10
Effect conc.:
201 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co on Kasterlee soil
Basis for effect:
reproduction
Remarks on result:
other: 95% CL: 124-327
Duration:
28 d
Dose descriptor:
EC10
Effect conc.:
122 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co in Aluminusa soil
Basis for effect:
reproduction
Remarks on result:
other: 95% CL: 59-244
Duration:
28 d
Dose descriptor:
EC10
Effect conc.:
100 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co in Woburn soil
Basis for effect:
reproduction
Remarks on result:
other: 95% CL: 42-216
Duration:
28 d
Dose descriptor:
EC10
Effect conc.:
130 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co in Sidney soil
Basis for effect:
reproduction
Remarks on result:
other: 95% CL: 72-231
Duration:
28 d
Dose descriptor:
EC10
Effect conc.:
426 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co in Souli II soil
Basis for effect:
reproduction
Remarks on result:
other: 95% CL: 310-584
Duration:
28 d
Dose descriptor:
EC10
Effect conc.:
385 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co in Brecy soil
Basis for effect:
reproduction
Remarks on result:
other: 955 CL: 228-637
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
163 mg/kg soil dw
Nominal / measured:
meas. (not specified)
Conc. based on:
other: added Co in Leuven soil
Basis for effect:
reproduction
Remarks on result:
other: No reliable EC10 available, NOEC used instead
Details on results:
not reported
Results with reference substance (positive control):
not applicable
Reported statistics and error estimates:
From the obtained concentration-response relationships, the EC50s and ECl0s (with 95% confidence limits) were calculated using the log-logistic response model (Haanstra et ai. , 1995). k y = l+(~JS X50 Where y = response of measured endpoint (e.g. number of juveniles or cocoons) k = response of measured endpoint at x = 0 s = slope parameter x = concentration (on a linear scale) Xso = ECso (median effective concentration) 9 The above mentioned model is re-parameterized to estimate both ECso and ECIO together in one run of the program: k Where y = response of measured endpoint (e.g. number of juveniles or cocoons) k = response of measured endpoint at x = 0 x = concentration (on a linear scale) Xso = ECso (median effective concentration) x)O = ECso (10% effective concentration) Model fitting and the calculations of the 95% confidence limits was carried out using LevenbergMarquardt (Levenberg, 1944; Marquardt, 1963), which is included in the Statistica 6.0 Software (Statsoft, Tulsa, OK). Comparison among ECso values based on the 95% confidence limits was performed following procedure described in Sprague and Fogels (1977). Reproduction of F candida, E. fetida and E. albidus after 28 or 42 days of exposure were statistically compared with those in the control soils using analysis of variance (ANOV A) followed by the Dunnett-test. When the assumption of normality or homogeneity of variance was not met, a non parametric analysis (Mann Whitney U-tests) was applied. Results of these analyses are expressed as p-values, with p < 0.05 were considered significant. These analyses were used to derive the No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) values for the different soils. The relationship between the toxicity data (NOEC, EClOs and ECsos) and the soil parameters were investigated using linear regression analysis (Statistica 6.0).

Any other information on results incl. tables

According to REACH guidance Chapter R. 10 (Table R.10 -1) EC 10 values are used preferentially for PNEC derivation and therefore NOEC values are only presented as supporting information. However, one NOEC value is used for PNEC derivation since the EC10 was not reliable.

 Duration  Endpoint  Effect Conc.  Nominal/Measured  Conc.based on  Basis for effect
 28 d NOEC    196 mg/kg soil dw   meas. (not specified)  other: total Co in Kasterlee soil  reproduction
 28 d  NOEC   170 mg/kg soil dw   meas. (not specified)  other: total Co in Leuven soil  
 reproduction
 28 d  NOEC   370 mg/kg soil dw   meas. (not specified)  other: total Co in Brecy soil  reproduction
 28 d  NOEC  88 mg/kg soil dw   meas. (not specified)  other: total Co in Jyndevad soil  reproduction
 28 d  NOEC  181 mg/kg soil dw   meas. (not specified)  other: total Co in Aluminusa soil  reproduction
 28 d  NOEC  179 mg/kg soil dw   meas. (not specified)  other: total Co in Woburn soil  reproduction
 28 d  NOEC  573 mg/kg soil dw   meas. (not specified)  other: total Co in Souli II soil  reproduction
 28 d  NOEC  <62 mg/kg soil dw  meas. (not specified)  other: total Co in Atherns soil  reproduction
 28 d  NOEC  162 mg/kg soil dw  meas. (not specified)  other: total Co in Sidney soil  reproduction

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In total, 9 results were selected for PNEC derivation: between 56 mg added Co/kg (Athens soil) and 385 mg added Co/kg (Souli II soil).
Executive summary:

not applicable