Magnesium

Toxicity to soil microorganisms

Administrative data

Endpoint:

toxicity to soil microorganisms

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: No guideline study, but well performed and well documented.

Data source

Reference

Reference Type:

publication

Title:

Effect of metals and other inorganic-ions on soil microbial activity - soil dehydrogenase assay as a simple toxicity test.

Author:

Rogers J.E., Li S.W.

Year:

1985

Bibliographic source:

Bulletin of Environmental Contamination and Toxicology 34/6: 858-865.

Materials and methods

Principles of method if other than guideline:

Dehydrogenease process.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

7487-88-9

Cas Number:

7487-88-9

IUPAC Name:

7487-88-9

Constituent 2

Reference substance name:

Magnesium sulphate

EC Number:

231-298-2

EC Name:

Magnesium sulphate

IUPAC Name:

231-298-2

Constituent 3

Reference substance name:

magnesium sulphate

IUPAC Name:

magnesium sulphate

Details on test material:

reagent grade Magnesium sulphate.

Sampling and analysis

Analytical monitoring:

no

Test substrate

Vehicle:

no

Test organisms

Test organisms (inoculum):

soil

Study design

Total exposure duration:

24 h

Test conditions

Test temperature:

27°C

Moisture:

22% of water holding capacity (400 g air dry soil + 87 ml distilled water)

Details on test conditions:

pH 7.6
2 replicates per treatment
incubation in the dark
1 g air-dry soil was amended with 0.2 mL of a 3% (w/v) solution of 2, 3, 4-triphenyl tetrazolium chloride (TTC) and 0.5 ml of a 0.5% (w/v) glucose solution in 25 mL centrifuge tubes
soil dehydrogenase activity was assessed as the mg TTC-formazan produced per kg soil per 24 h.

Nominal and measured concentrations:

nominal: 0, 30, 150, 300, 500, 1000, 3000, 5000 mg Mg/kg dry weight

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

> 5 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

magnesium

Basis for effect:

other: dehydrogenase

Remarks on result:

other: Natural surface soil enriched with 1% alfalfa; 3% inhibition at highest dose tested.

Effect concentrations 2

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

> 5 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

magnesium

Basis for effect:

other: dehydrogenase

Remarks on result:

other: Natural surface soil without alfalfa; 0% inhibition at highest dose tested.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

No guideline study, but well performed and well documented. However, only unbounded NOEC/EC10 values were reported and therefore these values were not considered for derivation of the PNEC, but used as supporting information.