Diarsenic trioxide

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

ISO 11268-2

Qualifier:

according to guideline

Guideline:

ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction)

Deviations:

yes

Remarks:

some adaptations for tropical regions

GLP compliance:

not specified

Specific details on test material used for the study:

Na2HAsO4·7H2O

Analytical monitoring:

yes

Details on sampling:

not available

Vehicle:

no

Details on preparation and application of test substrate:

salt solutions evenly distributed throughout the soil

Test organisms (species):

Eisenia andrei

Animal group:

annelids

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Remarks:

30 d equilibration after spiking prior to testing

Test temperature:

23

pH:

6.1 (tropical artificial soil)
4.4 (natural tropical soil)

Moisture:

60% of water holding capacity

Details on test conditions:

The laboratory cultures and all bioassays were carried out in a climate-controlled room with a temperature of 23 ± 2 °C and 12:12-h light/dark. Twenty-four hours before initiating the bioassays, the earthworms were acclimated to the untreated test soils. Only adult (clitellate) earthworms, with an individual body weight of 300–600 mg taken from synchronized cultures, were utilized in the assays.

Nominal and measured concentrations:

Nominal: 1, 5, 15, 4,5 and 135 As mg/kg soil dry weight

Reference substance (positive control):

no

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

15 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other:

Remarks:

tropical artificial soil (TAS)

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

45 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other:

Remarks:

tropical artificial soil (TAS)

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

22.7 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other:

Remarks:

tropical artificial soil (TAS)

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

>= 135 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other:

Remarks:

natural tropical soil (oxisol)

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight loss

Remarks on result:

other:

Remarks:

tropical artificial soil (TAS)

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight loss

Remarks on result:

other:

Remarks:

tropical artificial soil (TAS)

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 135 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight loss

Remarks on result:

other:

Remarks:

natural tropical soil (oxisol)

Results with reference substance (positive control):

not available

Reported statistics and error estimates:

Normality: Kolmogorov-Smirnov
Variance homogeneity: Bartlett
Differences: one-way ANOVA, Dunnett (p<0.05)
Exponential dose–response model (according to Environment Canada 2007)

Validity criteria fulfilled:

yes

Conclusions:

The 56 d NOEC and LOEC for reproduction of the earthworm Eisenia andrei amounted to 15 and 45 mg As/kg soil dry weight in tropical artificial soil, whereas effect concentrations were higher (>= 135 mg As/kg soil dry weight) in a natural tropical soil (Oxisol) (results based on added As concentrations in soil).

Reference 2

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 220 (Enchytraeid Reproduction Test)

Deviations:

no

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

Soil samples were taken for all nominal concentrations.

Vehicle:

no

Details on preparation and application of test substrate:

Arsenate was added as aqueous solution (Na2HAsO4)

Test organisms (species):

Enchytraeus albidus

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Age at test initiation: adult worms with a fully developed clitellum

ACCLIMATION
- Acclimation period: at least five years (cultured at the laboratory)
- Acclimation conditions: same as test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

6 wk

Test temperature:

20 ± 1 °C

pH:

pH 6

Moisture:

55% of water holding cpacity

Details on test conditions:

TEST SYSTEM
- Test container (material, size): glass vessel
- Amount of soil or substrate: 20 g wet weight
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE
- Composition (if artificial substrate): 70 % sand, 20 % kaolin clay, 10 % finely ground Sphagnum peat (as described in OECD guideline 207 (1984))

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

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- reproduction (number of juveniles), after 6 wk

TEST CONCENTRATIONS
- Spacing factor for test concentrations: ≤ 1.8

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 10, 18, 32, 56, 100 mg As/kg dry wt;
Nominal concentrations were analytically confirmed (measured values ≥ 80 % of nominal values)

Reference substance (positive control):

no

Key result

Duration:

42 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

juvenile production

Duration:

42 d

Dose descriptor:

LOEC

Effect conc.:

18 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

juvenile production

Duration:

42 d

Dose descriptor:

EC50

Effect conc.:

22.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

juvenile production

Remarks on result:

other: 95 % CI:16.4 - 30.9

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

90.2 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks on result:

other: 95 % CI: 71.6-210

Details on results:

Control mortality was < 10 %.

Reported statistics and error estimates:

EC50 values with 95 % confidence intervals were calculated using the probit method. LC50 values with 95 % confidence intervals were calculated using the moving average method. NOECs were calculated by Kruskal-Wallis ANOVA followed by post-hoc multiple comparisons.

Validity criteria fulfilled:

yes

Conclusions:

In a 42 d reproduction test with the enchytraeid worm Enchytraeus albidus following OECD guideline 220, a 42 d NOEC of 10 mg As/kg artificial soil as well as a 42 d EC50 of 22.9 mg As/kg artificial soil were determined for toxicity on reproduction (results based on added As concentrations).

Reference 3

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Deviations:

not applicable

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

Soil samples were taken for all nominal concentrations.

Vehicle:

no

Details on preparation and application of test substrate:

Arsenate was added as aqueous solution (Na2HAsO4).

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Source: Commercial earthworm breeding farm
- Age at test initiation: adult worms with a fully developed clitellum

ACCLIMATION
- Acclimation period: at least five years (cultured at the laboratory)
- Acclimation conditions: same as test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

3 wk

Test temperature:

20 ± 1 °C

pH:

pH 6

Moisture:

55% of water holding cpacity

Details on test conditions:

TEST SYSTEM
- Test container (material, size): glass vessel
- Amount of soil or substrate: 750 g wet weight; 2 % (dry weight) finely ground cow dung was supplied in a shallow depression in the test soil
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE
- Composition (if artificial substrate): 70 % sand, 20 % kaolin clay, 10 % finely ground Sphagnum peat (as described in OECD guideline 207 (1984))

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

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Number of cocoons, at test end

TEST CONCENTRATIONS
- Spacing factor for test concentrations: ≤ 1.8

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 10, 18, 32, 56, 100 mg As/kg dry wt;
Nominal concentrations were analytically confirmed (measured values ≥ 80 % of nominal values)

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

cocoon production

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

18 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

cocoon production

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

10.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

cocoon production

Remarks on result:

other: 95 % CI: 4.73-14.3

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks on result:

other: unbound NOEC

Details on results:

Control mortality was < 10 %.

Reported statistics and error estimates:

EC50 values with 95 % confidence intervals were calculated using the probit method. LC50 values with 95 % confidence intervals were calculated using the moving average method. NOECs were calculated by Kruskal-Wallis ANOVA followed by post-hoc multiple comparisons.

Validity criteria fulfilled:

not specified

Remarks:

Juveniles per replicate and coefficient of variation of reproduction not reported

Conclusions:

In a 21 d reproduction test with the earthworm Eisenia fetida similar to OECD guideline 222, a 21 d NOEC of 10 mg As/kg artificial soil as well as a 21 d EC50 of 10.8 mg As/kg artificial soil was determined for toxicity on reproduction (results based on added As concentrations).

Reference 4

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

GLP compliance:

not specified

Specific details on test material used for the study:

Na2HAsO4.7H2O

Analytical monitoring:

yes

Vehicle:

no

Details on preparation and application of test substrate:

500 g of soil (dry weight) was spiked with aqueous As solutions

Test organisms (species):

Eisenia andrei

Animal group:

annelids

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

56 d

Remarks:

28 days equilibration after spiking prior to testing

Test temperature:

20 °C

pH:

H1 loam: 7.96
H2 loam: 8.67
H3 silt loam: 8.79
H4 sandy loam: 6.74
H5 loam: 7.2
H6 sandy loam: 5.87
H7 clay: 7.03

Moisture:

60% of WHC

Details on test conditions:

After spiking, the soils were moistened to 60 % of their WHC and incubated for 4 weeks at 25±1 °C and 60 % air humidity, with a light to dark cycle of 10:14 h. Soil moisture content was checked and, if needed, readjusted weekly.
Ten adult earthworms were added to each test container after being gently cleaned on moistened paper towels and weighed. To feed the worms, 25 g of horse manure:distilled water (1:4 ratio) was added to each container. The containers were kept in an incubator chamber at 20 °C with 12 h of light per day. Container weights were monitored weekly to maintain moisture content, and additional food was added when required.

Nominal and measured concentrations:

Nominal: 0, 50, 100, 300, and 600 mg As/kg soil dry weight
(measured concentrations were between 80 and 97% (92% on average) of nominal values)

Reference substance (positive control):

no

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

300 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H1 loam

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H1 loam

Duration:

28 d

Dose descriptor:

LC10

Effect conc.:

606 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

As (total concentration)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H1 loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H2 loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H3 silt loam

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

300 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H3 silt loam

Duration:

28 d

Dose descriptor:

LC10

Effect conc.:

132 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

As (total concentration)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H3 silt loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H4 sandy loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H5 loam

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

300 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H5 loam

Duration:

28 d

Dose descriptor:

LC10

Effect conc.:

188 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

As (total concentration)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H5 loam

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

<= 50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H6 sandy loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

mortality

Remarks:

not most sensitive endpoint

Remarks on result:

other: H7 clay

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

300 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H1 loam

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H1 loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H2 loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

300 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H3 silt loam

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H3 silt loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H4 sandy loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

300 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H5 loam

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H5 loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H6 sandy loam

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H6 sandy loam

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

growth

Remarks:

weight - not most sensitive endpoint

Remarks on result:

other: H7 clay

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H1 loam

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

300 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H1 loam

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

300 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H2 loam

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

600 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H2 loam

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

<= 50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H3 silt loam

Duration:

56 d

Dose descriptor:

EC10

Remarks:

EC10 < lowest test dose

Effect conc.:

41.6 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H3 silt loam

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H4 sandy loam

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H4 sandy loam

Key result

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

67.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H4 sandy loam

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

<= 50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H5 loam

Duration:

56 d

Dose descriptor:

EC10

Remarks:

EC10 < lowest test dose

Effect conc.:

17.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H5 loam

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

<= 50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H6 sandy loam

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H7 clay

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H7 clay

Duration:

56 d

Dose descriptor:

EC10

Remarks:

EC10 < lowest test dose

Effect conc.:

35.2 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: H7 clay

Results with reference substance (positive control):

not available

Reported statistics and error estimates:

Mortality:
- Normality with Kolmogorov-Smirnov
- Differences with ANOVA; Tukey HSD test (p<0.05)
- EC10 with log-logistic dose-response model fitted to the data (Doelman and Haanstra 1989)
Weight:
- Normality with Kolmogorov-Smirnov
- Differences with ANOVA; Tukey HSD test (p<0.05)
Reproduction:
- Normality with Kolmogorov-Smirnov
- Differences with ANOVA; Tukey HSD test (p<0.05)
- EC10 with log-logistic dose-response model fitted to the data (Doelman and Haanstra 1989)

Validity criteria fulfilled:

yes

Conclusions:

The results of a 56 d study on the effect of arsenic to the reproduction of the earthworm Eisenia fetida were largely depending on soil properties.
Strong hormesis was observed in 2 Spanish loam soils (H1 and H2), and hence, the EC10 could not be derived with log-logistic dose-response modelling.
The nominal NOEC and LOEC amounted to 100 and 300 mg As/kg soil dry weight in H1, and to 300 and 600 mg As/kg soil dry weight in H2.
Effects were observed at the nominal lowest test dose of 50 mg As/kg soil dry weight (unbounded LOEC) in a silt loam (H3), a loam (H5), and a sandy loam (H6) soil.
The NOEC and LOEC amounted to 50 and 100 mg As/kg soil dry weight in another sandy loam (H4) and in a clay (H7) soil.
Only for H4, a nominal EC10 of 67.8 mg As/kg soil dry weight (on total As: 82 mg As/kg soil dry weight) could be derived.
For H3, H5, H6, and H7, EC10 were lower than the lowest test dose and therefore the uncertainty was judged too high to consider these EC10 values for derivation of the PNEC. All results are based on added As concentrations in soil.

Reference 5

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction)

Version / remarks:

Eisenia fetida

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Version / remarks:

Eisenia fetida

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

Na2HAsO4.7H2O

Analytical monitoring:

yes

Remarks:

background concentration and nominal concentrations confirmed

Vehicle:

no

Details on preparation and application of test substrate:

Test substance added as aqueous solution and mixed with soil

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Study type:

laboratory study

Substrate type:

natural soil

Remarks:

reference and sampled soils tested

Limit test:

no

Total exposure duration:

56 d

Remarks:

7 days equilibration after spiking prior to testing

Test temperature:

20

pH:

LUFA 2.2 - Dystric Cambisol: 5.6
Refesol 05-G: 5.2
Refesol 06-A: 7.3
Ter Munck - Haplic Luvisol: 5.7
Woburn - Dystric Cambisol: 6.0
Zegveld - Histosol: 4.8

Moisture:

LUFA 2.2 - Dystric Cambisol: 45% of WHC
Refesol 05-G: 45% of WHC
Refesol 06-A: 45% of WHC
Ter Munck - Haplic Luvisol: 58.4% of WHC
Woburn - Dystric Cambisol: 53.1% of WHC
Zegveld - Histosol: 60% of WHC

Details on test conditions:

The test vessels were stored in a climate chamber at 20 ±2 °C with a light cycle of 16 h:8 h day:night.
The light intensity during the light periods varied between 400 and 800 lux.
Worms were fed at day one by adding 15 g (wet weight) of cow manure to each test vessel.
Afterwards the initial weight of each test vessel was documented in order to be able to correct for evaporation during the experiment (at day 7, 14, and 21).
Weight loss was compensated by adding the respective amount of deionised water.
Worms were fed weekly with 15 g of cow manure, except for the treatments, in which the feeding rate was reduced.
In those cases the amount of food added to the vessels was reduced accordingly to 8 or 4 g.
At day 28 of the experiment, adult worms were taken from the soil, after again correcting for weight loss in the vessels.
They were washed, counted, and weighted. Morphological changes were reported, if observed, and it was checked whether the remaining soil contained cocoons or juvenile worms.
Once again 15 g of cow manure was added (for the last time). The weight of the test vessels was again determined to correct for evaporation on a weekly basis (at day 35, 42, and 49).

Nominal and measured concentrations:

Nominal doses:
LUFA 2.2 - Dystric Cambisol: 0, 10, 20, 40, 80, 160, and 320 mg As/kg soil dry weight
Refesol 05-G: 0, 62.5, 125, 250, 500, and 1000 mg As/kg soil dry weight
Refesol 06-A: 0, 20, 40, 80, 160, and 320 mg As/kg soil dry weight
Ter Munck - Haplic Luvisol: 0, 15.63, 31.25, 62.5, 125, and 250 mg As/kg soil dry weight
Woburn - Dystric Cambisol: 0, 31.25, 62.5, 125, 250, 500, and 1000 mg As/kg soil dry weight
Zegveld - Histosol: 0, 62.5, 125, 250, 500, and 1000 mg As/kg soil dry weight

Measured As concentrations are within 20% of nominal values.

Reference substance (positive control):

no

Key result

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

60.4 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: LUFA 2.2

Remarks:

Dystric Cambisol

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

40 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: LUFA 2.2

Remarks:

Dystric Cambisol

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

80 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: LUFA 2.2

Remarks:

Dystric Cambisol

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

102.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: LUFA 2.2

Remarks:

Dystric Cambisol

Key result

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

413.1 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Refesol 05-G

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

250 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Refesol 05-G

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Refesol 05-G

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

453.6 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Refesol 05-G

Key result

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

188.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Refesol 06-A

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

160 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Refesol 06-A

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

320 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Refesol 06-A

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

289.4 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Refesol 06-A

Key result

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

32 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Ter Munck

Remarks:

Haplic Luvisol

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

31.25 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Ter Munck

Remarks:

Haplic Luvisol

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

62.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Ter Munck

Remarks:

Haplic Luvisol

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

54 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Ter Munck

Remarks:

Haplic Luvisol

Key result

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

272.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Woburn

Remarks:

Dystric Cambisol

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

250 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Woburn

Remarks:

Dystric Cambisol

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Woburn

Remarks:

Dystric Cambisol

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

383.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Woburn

Remarks:

Dystric Cambisol

Key result

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

237.2 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Zegveld

Remarks:

Histosol

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Zegveld

Remarks:

Histosol

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Zegveld

Remarks:

Histosol

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

877 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

As (added dose)

Basis for effect:

reproduction

Remarks:

number of juveniles

Remarks on result:

other: Zegveld

Remarks:

Histosol

Results with reference substance (positive control):

not available

Reported statistics and error estimates:

Normality of the data:
checked with Kolmogorov-Smirnov or Shapiro-Wilk's test

Variance homogeneity of the data:
Levene's or Cochran test

NOEC and LOEC:
- In case data of normal distribution, homoscedasticity and a monotone dose-response relationship: Williams' Multiple Sequential t-test
- In case of normal distribution and variance heterogeneinty: one-sided Welch's t-test
- In case of normal distribution and homoscedasticity, but absence of a monotone relationship: Dunnett's t-test
- In case data were not normally distributed, but homoscedastic: Jonckheere-Terpstra test
- In case data were not normally distributed and heteroscedastic: Bonferroni U-test
- In case data were not normally distributed and the dose-response relationship was not monotone: Bonferroni Median test
(α = 0.05)

ECx values were determined with both linear and non-linear regression models
It was checked for the best fit (R2, Chi2, AIC) after performing an F-test to control significance of the dose response relationship

Validity criteria fulfilled:

yes

Conclusions:

The 56-d EC10 for the effect of arsenic to the reproduction of Eisenia fetida in six different soils ranged between 32.0 and 413.1 mg As/kg soil dry weight (based on added As concentrations in soil).

Description of key information

In total, 13 reliable EC₁₀ or NOEC values for chronic arsenic toxicity to terrestrial invertebrates except arthropods were retrieved from 4 published studies. All data were derived from soils amended with disodium hydrogen arsenate salts. The data cover As toxicity to reproduction of 3 different species (Eisenia andrei, Eisenia fetida and Enchytraeus albidus). NOEC and EC₁₀ values vary between 10.0 mg As/kg dw for Eisenia andrei and 413 mg As/kg dw for Eisenia fetida. All NOEC and EC₁₀ values are expressed based on added elemental As concentrations in soil. All reliable NOEC and EC₁₀ values were taken forward to the derivation of the PNEC according to the statistical extrapolation approach.