Barium nitrate

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: 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 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants)

Principles of method if other than guideline:

28-d collembolan reproduction test (Folsomia candida), 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

Application method:

soil

Analytical monitoring:

yes

Test organisms (species):

Folsomia candida

Animal group:

Collembola (soil-dwelling springtail)

Details on test organisms:

no data provided

Study type:

laboratory study

Limit test:

no

Total exposure duration:

28 d

pH (if soil or dung study):

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

Humidity:

according to guideline specification (88% 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) -1560 mg/kg

Reference substance (positive control):

yes

Remarks:

carbamate

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

211 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Basis for effect:

mortality

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

375 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Basis for effect:

mortality

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

211 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Basis for effect:

reproduction

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

375 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Basis for effect:

reproduction

Duration:

28 d

Dose descriptor:

other: EC20

Effect conc.:

165 mg/kg soil dw

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Basis for effect:

reproduction

Remarks on result:

other: 49-281

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

478 mg/kg soil ww

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Basis for effect:

reproduction

Remarks on result:

other: 325-632

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.

Conclusions:

A guideline study with the collembolan Folsomia candida, 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 and reproduction of 211 and 375 mg Ba/kg soil dw, respectively.

Description of key information

A guideline study with the collembolan Folsomia candida has been conducted with barium (Kuperman et al., 2006). NOEC, LOEC, EC20 and EC50 values - based on measured levels - are reported for survival and/or reproduction. A long-term NOEC for both mortality and reproduction of 211 mg Ba/kg soil dw was obtained and can be considered as key value for this endpoint. 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 dwelling arthropods:

211 mg/kg soil dw

Additional information

One study was available to cover this endpoint. The key study is a study from 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 guideline study with the collembolan Folsomia candida, using natural soil, has been conducted with barium nitrate in this study, yielding a NOEC and LOEC for both mortality and reproduction of 211 and 375 mg Ba/kg soil dw.