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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
Study period:
2006-09-13 - 2006-11-17
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference
Reference Type:
secondary source
Title:
Unnamed
Year:
2006
Report Date:
2006

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Tests for Toxicity of Contaminated Soil to Earthworms (Eisenia andrei, Eisenia fetida, or Lumbricus terrestris).Report EPS1/RM/43, June 2004. Method Development and Applications Section, Environmental Technology Centre, Environment Canada, Ottawa, Ontari.
Principles of method if other than guideline:
Study conducted according to Environment Canada test method.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes

Test organisms

Test organisms (species):
other: Eisenia andrei
Animal group:
annelids
Details on test organisms:
Eisenia andrei 35-d adult;
Source: Stantec Soils Laboratory (In-house culture)

Study design

Study type:
laboratory study
Substrate type:
artificial soil
Limit test:
no
Total exposure duration:
63 d
Remarks:
35-d adult survival

Test conditions

Test temperature:
20 ± 2°C
pH:
Soil pH ranged from 6.19 to 7.64 for the beginning of all tests and from 3.92 to 7.40 for the end of all tests.
Moisture:
Soil moisture content of all treatments in all tests was independent of DEG concentrations and ranged from 59 to116% of the soil water holding capacity (WHC) for the beginning of all tests and from 44 to 91% of the soil WHC for the end of the invertebrate tests.
Details on test conditions:
The artificial soil was formulated in the Stantec laboratory from natural ingredients of silica sand (70%), kaolinite clay (20%), and Sphagnum sp. peat (10%) and it was buffered to a neutral pH range (6.0 to 7.5) with calcium carbonate.
Test unit (chamber): Glass 500-mL mason jar
Amount of soil: 270 g wet wt.
Photoperiod (h): 16 light : 8 dark
Number of replicate test units per treatment: 10
Number of organisms per test unit: 2
Lighting (Type & Intensity): Fluorescent, 400-800 Lux
Nominal and measured concentrations:
0, 400, 800, 1600, 3200, 6400, 9600, 12800, 25600, 51200, 86355 mg/kg
The recovery of DEG from the beginning of the range-finding tests was good and ranged from 75 to 90%. DEG recovery on Day 0 of the northern
wheatgrass test was similar among all but the lowest (200 mg/kg) treatments and ranged from 85 to 102%. The recovery in the lowest treatment was below the detection limit. There was evidence of loss of DEG from soil over time; measurable concentrations of DEG were only detected in the highest concentration (25600 mg/kg) at Days 7 and 21 of the test. In addition, the % DEG recovery in these concentrations also decreased over time with 102, 74 and 63% recovery at Days 0, 7 and 21, respectively.

Results and discussion

Effect concentrationsopen allclose all
Duration:
63 d
Dose descriptor:
LC50
Effect conc.:
10 974 mg/kg soil dw
Duration:
63 d
Dose descriptor:
other: IC50
Effect conc.:
8 868 mg/kg soil dw
Basis for effect:
reproduction
Remarks:
number of progeny
Details on results:
Eisenia andrei 35-d adult survival was affected adversely following exposure to DEG in AS, resulting in an LC50 of 10,974 mg/kg. 63-day reproduction metrics were affected adversely following exposure to DEG; however, the concentration-response curve was atypical. Reproduction increased in response to the low and intermediate concentrations relative to that in the control. This effect was particularly pronounced in the 1600 mg/kg treatment. The reproduction in this treatment was more variable than in the other treatment, particularly for the mass metrics. When the data were inspected, all the data points appeared to be attributable to biological variation and the effect was still apparent when outliers were removed for visual assessment of the toxicity curves. Despite the unusual concentration response curves, linear and non-linear regressions were fit to the data reasonably well and the IC50s ranged from 8868 to 10,100 mg/kg for number of progeny produced and progeny wet mass, respectively.
Reported statistics and error estimates:
Analyses were performed with SYSTAT 11 (SPSS, 2004).

Applicant's summary and conclusion