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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study

Data source

Reference
Reference Type:
publication
Title:
Effects of eight polycyclic aromatic compounds on the survival and reproduction of Enchytraeus crypticus (Oligochaeta, clitellata)
Author:
Sverdrup LE, Jensen J, Kelley AE, Krogh PH, Stenersen J
Year:
2002
Bibliographic source:
Environ. Toxicol. Chem., 21, 109-114

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 220 (Enchytraeid Reproduction Test)
Deviations:
no
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Fluorene
Source: Sigma-Aldrich
Purity: >96%
Fraction in wash oil: 4 - 5 %
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
--

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Initial concentration tested

Test substrate

Vehicle:
yes
Details on preparation and application of test substrate:
Application: Dissolved in acetone

- Method of mixing into soil: Equal volumes of acetone (4 ml) added to all treatments with the test substance in solution to 20 ±0.05 g soil sample,
mixing, followed by evaporation of the solvent for 24 h.

-Vehicle controls: Acetone-treated test soil without test substance
- Chemical name of vehicle: Acetone
- Evaporation of vehicle before use: yes

Test organisms

Test organisms (species):
other: Enchytraeus crypticus
Animal group:
annelids
Details on test organisms:
TEST ORGANISM
- Common name: Earthworm
- Source of the initial stock: Danish National Environmental Research Institute (Silkeborg, DK)
- Only sexually mature animals of approximately the same size were used.

Culturing techniques: In petri dishes with Bacto agar, worms mass-bred, kept at 20 ±1 °C under 12:12 light:dark photoperiod, Feed: oatmeal

Study design

Study type:
laboratory study
Substrate type:
artificial soil
Limit test:
no
Total exposure duration:
21 d

Test conditions

Test temperature:
20 ±1 °C
pH:
see details below
Moisture:
65 % of water-holding capacity (addition of 4 ml water each)
Details on test conditions:
TEST SYSTEM
- Test container (material, size): Plastic cylinders 5 cm high and 3.5 inner diameter
- Amount of soil or substrate: 20 g soil dry weight
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4
- No. of replicates per vehicle control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
Artificial soil test substrate: Danish agricultural soil (Askov, Jutland)
- Composition: Sandy loam
coarse sand (0.2 – 2 mm) 38.4 %,
fine sand (0.063 – 0.2 mm) 23.6 %,
coarse silt (0.02 – 0.063 mm) 10.0 %,
fine silt (0.002 – 0.02 mm) 12.3 %,
clay (<0.002 mm) 13 %,
humus 2.8 %
Organic carbon content: 1.6 %,
Soil pH 6.2, no adjustment
Density 1.135 g/cm3
Cation exchange capacity: 8.14 meq/100 g

- Pretreatment of soil prior to use: Drying at 80 °C for 24 h, sieving: (2 mm mesh)
- Stability and homogeneity of test material in the medium: no data (test performed in closed vessels due to significant volatility of test substrate)

OTHER TEST CONDITIONS
- Photoperiod: 12:12 h (light:dark)
- Light intensity: 400-800 lux

At the start of the test, 30 mg food (crushed oatmeal) mixed into the soil of each replicate.
The test containers were opened after 7 and 14 d for feeding and water control.

EFFECT PARAMETERS MEASURED: Mortality, reproduction

VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Range finding study: Highest test concentration was determined in range-finding studies, and a geometric series of 9 test levels
separated by a factor of 2 was run
- Test concentrations: 10, 20, 40, 80, 160, 320, 640, 1280 and 2560 mg/kg soil d.w. (nominal),
- Initial average measured concentration (% of nominal): 74.8 %
Nominal and measured concentrations:
nominal: 10, 20, 40, 80, 160, 320, 640, 1280 and 2560 mg/kg soil d.w.
Average measured initial concentrations (% of nominal): 74.8 %
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
21 d
Dose descriptor:
EC10
Effect conc.:
31 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
reproduction
Remarks on result:
other: original EC10 normalised to standard soil with 2 % organic carbon content
Duration:
21 d
Dose descriptor:
EC10
Effect conc.:
25 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
reproduction
Remarks on result:
other: 95% C.I.: 0 - 39 mg/kg soil dw
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
55 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
reproduction
Remarks on result:
other: 94% C.I.: 46 - 55 mg/kg soil dw
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
27 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
reproduction
Results with reference substance (positive control):
--
Reported statistics and error estimates:
Estimates of the concentration that caused a 10 and 50% reduction of the reproductive output (EC10 and EC50) were calculated by linear interpolation, and the CI intervals were calculated by the Icp method (Inhibition concentration approach acc. to Norberg-King 1993.
Estimations that caused 50% reduction in survival (LC50) were done using probit analysis in ASA/STAT. NOAEC were assessed using analysis of variance (ANOVA) and Dunnett´s procedure (at 5% significance level) after testing of fulfilment of ANOVA requirements using ASA/Lab software.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
based on mortality (<2 % in control) and reproduction rate