Barium nitrate

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:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Guideline test, but conducted in a natural soil that promotes bioavailability of metal cations (e.g., Ba): relatively low pH , low organic matter, low cation exchange capacity, and high sand content.

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

21-d earthworm reproduction test, measuring adult survival and juvenile production.
Method was modified for use with natural soil having physical and chemical characteristics that support a relatively high level of metal bioavailability. Modifications included different soil hydration levels.

GLP compliance:

not specified

Analytical monitoring:

yes

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

no data provided

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

21 d

pH:

control soil pH: 5.29
pH decreased with increasing substance-levels, but the decrease was less than 1 pH-unit

Moisture:

according to guideline specification (100% of the water holding capacity)

Details on test conditions:

soil type: Sassafras sandy loam SSL (fine-loamy, siliceous, mesic Typic Hapludult), collected from open grassland field; 71% sand, 18% silt, 11% caly, 1.2% organic matter, 4.3 cmol/kg CEC
- 7-9 test concentrations (not specified)
- 4 replicates/concentration
- no further details are provided
- soils were aged and weathered for 3 weeks

Nominal and measured concentrations:

7-9 concentrations; exact nominal/measured levels not specified
measured range: 34 (control) - 3700 mg/kg

Reference substance (positive control):

yes

Remarks:

4-nitrophenol

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 348 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

mortality

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

1 585 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

mortality

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

258 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

433 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

other: EC20

Effect conc.:

370 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

reproduction

Remarks on result:

other: 230-510

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

664 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

reproduction

Remarks on result:

other: 558-770

Details on results:

Good overal agreement among nominal and measured concentrations was noted.
Ba-background in SSL soil was 34 mg/kg
Barium concentrations (in excess of background) in the experimental treatments ranged from 88 to 139%, and averaged 111% of nominal.

Reported statistics and error estimates:

Toxicity data were analyzed using non-linear regression models. Variances of the residuals were examined to decide wether to weight the data and to select potential models. The logistic (Gompertz) model was used.
Analysis of variance was used to determine the bounded NOEC and LOEC for adult survival or reproduction data. Mean separations were determined using Fisher's least-significant-difference pairwise comparison tests.

Validity criteria fulfilled:

not specified

Conclusions:

A guideline study with the earthworm Eisenia fetida, using a natural soil, has been conducted with barium nitrate. NOEC, LOEC, EC20 and EC50 values - based on measured levels - are reported for survival and/or reproduction. Data can be used for the effects assessment of barium in the terrestrial compartment. Results of definitive tests produced bounded NOEC and LOEC values for adult survival of 1,348 and 1,585 mg Ba/kg soil dw,
respectively, for earthworms. The NOEC and LOEC values for reproduction were 258 and 433 mg Ba/kg soil dw, respectively.

Reference 2

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Guideline test, but conducted in a natural soil that promotes bioavailability of metal cations (e.g., Ba): relatively low pH , low organic matter, low cation exchange capacity, and high sand content

Qualifier:

according to guideline

Guideline:

other: ISO 16387: Soil quality: Effects of pollutants on Enchytaeidae (Enchytaeus sp.) - Determination of effects on reproduction and survival

Principles of method if other than guideline:

28-d enchytraeid reproduction test, measuring adult survival and juvenile production of the potworm E. crypticus.
Method was modified for use with natural soil having physical and chemical characteristics that support a relatively high level of metal bioavailability. Modifications included different soil hydration levels and duration of the test (28d instead of 42d) due to the shorter generation time of E. crypticus compared to E. albidus.

GLP compliance:

not specified

Analytical monitoring:

yes

Test organisms (species):

other: Enchytraeus crypticus

Animal group:

annelids

Details on test organisms:

no data provided

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

28 d

pH:

control soil pH: 5.29
pH decreased with increasing substance-levels, but the decrease was less than 1 pH-unit

Moisture:

according to guideline specification (100% of the water holding capacity)

Details on test conditions:

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- soil type: Sassafras sandy loam SSL (fine-loamy, siliceous, mesic Typic Hapludult), collected from open grassland field; 71% sand, 18% silt, 11% caly, 1.2% organic matter, 4.3 cmol/kg CEC
- soils were aged and weathered for 3 weeks

TEST SYSTEM
- 7-9 test concentrations (not specified)
- 4 replicates/concentration
- no further details are provided

Nominal and measured concentrations:

7-9 concentrations; exact nominal/measured levels not specified
measured range: 34 (control) -2110 mg/kg

Reference substance (positive control):

yes

Remarks:

4-nitrophenol

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 800 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

mortality

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

2 000 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

mortality

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

433 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

689 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

other: EC20

Effect conc.:

585 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

reproduction

Remarks on result:

other: 447-722

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

947 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Ba

Basis for effect:

reproduction

Remarks on result:

other: 830-1064

Details on results:

Good overal agreement among nominal and measured concentrations was noted.
Ba-background in SSL soil was 34 mg/kg.
Barium concentrations (in excess of background) in the experimental treatments ranged from 88 to 139%, and averaged 111% of nominal.

Reported statistics and error estimates:

Toxicity data were analyzed using non-linear regression models. Variances of the residuals were examined to decide wether to weight the data and to select potential models. The logistic (Gompertz) model was used.
Analysis of variance was used to determine the bounded NOEC and LOEC for adult survival or reproduction data. Mean separations were determined using Fisher's least-significant-difference pairwise comparison tests.

Validity criteria fulfilled:

not specified

Conclusions:

A guideline study with the enchytraeid Enchytraeus crypticus, using a natural soil, has been conducted with barium nitrate. NOEC, LOEC, EC20 and EC50 values - based on measured levels - are reported for survival and/or reproduction. Data can be used for the effects assessment of barium in the terrestrial compartment. Results of definitive tests produced bounded NOEC and LOEC values for adult survival of 1,800 and 2,000 mg Ba/kg soil dw, respectively, for enchytraeids. The NOEC and LOEC for reproduction were 433 and 689 mg Ba/kg soil dw, respectively.

Description of key information

A guideline study with earthworm and potworm, using natural soil, has been conducted with barium nitrate (Kuperman et al., 2006). NOEC, LOEC, EC20 and EC50 values - based on measured levels - are reported for survival and/or reproduction. Data can be used for the effect assessment of barium in the terrestrial compartment. The key NOEC was a 21-d NOEC for reproduction of 258 mg Ba/kg soil dw obtained in the 21-d earthworm reproduction test. The data can be used for the effect assessment of barium in the terrestrial compartment.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:

258 mg/kg soil dw

Additional information

One key study was available to cover this endpoint (Kuperman et al., 2006). This study was designed to produce benchmark data for the development of Soil Screening Levels (Eco-SSLs) for Ba, Be, Mn and Sb for soil organisms.

A 28-d enchytraeid reproduction test, measuring adult survival and juvenile production by the potworm Enchytraeus crypticus, and a 21-d earthworm reproduction test, measuring adult survival and juvenile production, were performed in this study.

The lowest NOEC and LOEC values obtained from these studies were a NOEC and LOEC for reproduction of the earthworm Eisenia fetida of 258 and 433 mg Ba/kg soil dw, respectively, and a NOEC and LOEC for reproduction of the potworm Enchytraeus crypticus of 433 and 689 mg Ba/kg soil dw, respectively. The lowest NOEC can be considered as the key value.