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Ecotoxicological information

Toxicity to terrestrial arthropods

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Administrative data

Endpoint:
toxicity to terrestrial arthropods: long-term
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
No details on analytical verification of test material concentration. Not GLP compliant. Minimum number of test concentrations used and spacing factor is not appropriate for derivation of ECx. Composition of soil is slightly different from guidance recommendations.

Data source

Reference
Reference Type:
publication
Title:
Impact of platinum group elements on the soil invertebrate Folsomia candida
Author:
Nemcova B. et al.
Year:
2013
Bibliographic source:
Neuroendocrinology Letters, 34(2), 5-10

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 232 (Collembolan Reproduction Test in Soil)
GLP compliance:
no
Application method:
soil

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: solid
Specific details on test material used for the study:
99.999%

Sampling and analysis

Analytical monitoring:
not specified
Details on sampling:
None.

Test substrate

Details on preparation and application of test substrate:
Test material dissolved in appropriate amount of deionised water to attain 50% MWHC.
Stock solution made at 10 mmol/L (0.4433 g PdCl2 per 250 mL deionised water).
Test item mixed in soil immediately before use.

Test organisms

Test organisms (species):
Folsomia candida
Animal group:
Collembola (soil-dwelling springtail)
Details on test organisms:
- Source: Ecotoxicological laboratory of the University of Veterinary and Pharmaceutical Sciences

The following information was not specified but assumed to be the same as the study for platinum tetrachloride by Nemcova, 2012 ("Impact of platinum on the soil invertebrate Folsomia candida". Neuroendocrinology Letters, 33(3), 173-178).
- Age at test initiation (mean and range, SD): young adults, 10-12 days of age
- Substrate: plaster of Paris/charcoal mixture, 9:1
- Feeding: fed twice a week with dried baker's yeast, 24 hr fasting before test start
- Temperature: 20 +/- 1 C
- Lighting: dark

Study design

Study type:
laboratory study
Limit test:
no
Total exposure duration:
28 d
Post exposure observation period:
None.

Test conditions

Test temperature:
20 °C
pH (if soil or dung study):
6.0 +/- 0.5
Adjusted with calcium carbonate.
pH analysed in a 1:5 mixture of soil and 1 M potassium chloride
Humidity:
50% of maximum water holding capacity (MWHC)
Photoperiod and lighting:
Light/dark cycle: 16/8
Light intensity: 400 - 800 Lux
Details on test conditions:
- Test container (material, size): glass, capped with polyethylene lid and sealed with Parafilm (with a small hole to allow airflow)
- Amount of soil or substrate: 30g wet weight
- No. of organisms per container (treatment): 10 synchronised springtails
- No. of replicates per treatment group: 5
- Substrate: standard artificial soil
- % sand: 70
- % silt: 0
- % clay: 20 (kaolin)
- % organic material: 10 (Sphagnum peat, finely ground)
- Feeding: 2 mg granulated dry yeast on days 1 and 14
Nominal and measured concentrations:
Nominal concentrations: 5, 10, 25, 50 and 100 µM PdCl2 per vessel
Reference substance (positive control):
yes
Remarks:
boric acid

Results and discussion

Effect concentrationsopen allclose all
Duration:
28 d
Dose descriptor:
EC50
Effect conc.:
21 other: µmol/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Remarks on result:
other: corresponding to 0.43 mg Pd/kg(dw)
Duration:
28 d
Dose descriptor:
NOEC
Remarks:
determined as LOEC/2 (effect at first dose is 19%)
Effect conc.:
2.5 other: µmol/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Remarks on result:
other:
Remarks:
corresponds to 0.05 mg Pd/kg (dry soil)
Key result
Duration:
28 d
Dose descriptor:
EC10
Remarks:
self-calculated from data
Effect conc.:
71.3 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
element
Basis for effect:
reproduction
Duration:
28 d
Dose descriptor:
EC50
Remarks:
self calculated from data
Effect conc.:
584 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
element
Basis for effect:
reproduction
Details on results:
In the control treatment, adult survival was 100%, the average number of juveniles per vessel was 1280 and the CV was 3%.
No significant effect of PdCl2 on mortality was found.
Survival was not affect to such an extent as reproduction.
Results with reference substance (positive control):
28d EC50 for reproduction is 101.5 mg/kg for boric acid; expected value is 100 mg/kg dry weight soil.
Reported statistics and error estimates:
One-sided ANOVA followed by analysis of means by the LSD test.
Levene's method to test for homogeneity of variances.
Non-homogenous parameters were log-transformed prior to analysis and compared with the non-parametric Kruskal-Wallis test.

Any other information on results incl. tables

Test material concntration (uM)  # juveniles produced  CV (%)  SD  Inhibition of reproduction (%) No of adults at beginning of test   No of adults at end of test (average) inhibition of mortality (%) 
 5  1042.4  5  48.5  19  10

 9.6

 4
 10  761.6  4  32.6  41  10  9.6  4
25  589.4  6  36.5  54  10  9.6  4
 50  463.0  7  34.5  64  10  10  0
 100  262.4  13  34.6  80  10  10  0

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Palladium dichloride was shown to have an effect on the reproduction of Folsomia candida under the chosen test conditions. The 28-day reproduction EC50 was found to be 21.0 µmol/L, corresponding to an estimated EC50 of 584 mg Pd/kg(dw). The EC10 values were estimated at 2.57 µmol/L, corresponding to an estimated EC10 of 71.3 mg Pd/kg(dw).
Executive summary:

The influence of palladium dichloride on the mortality, reproduction and growth of the species Folsomia candida was investigated according to OECD Test Guideline 232 (also CSN ISO 11267), "Inhibition of reproduction of Collembola by soil pollutants". Test specimens were placed in synthetic soil treated with nominal palladium dichloride concentrations of 5, 10, 25, 50 and 100 µM. Soil moisture was maintained at 50% MWHC and adjusted at three times a week with more water to account for system mass losses. No significant differences between the test concentrations and control were found for adult mortality. The 28-day reproduction EC50 was found to be 21.0 µmol/L, corresponding to an estimated  EC50 of 584 mg Pd/kg(dw). The EC10 values were estimated at 2.57 µmol/L, corresponding to an estimated EC10 of 71.3 mg Pd/kg(dw)

The study has a reliability rating of 3 as there is no evidence of analytical verification of test material concentrations. The number of test concentrations tested was not appropriate for the derivation of the ECx (however, is suitable for derivation of the NOEC or LOEC) and the spacing factor is also higher than recommended. The composition of artificial soil varied slightly from that recommended in the guideline. The study was not conducted according to GLP.