Manganese

Toxicity to soil microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Peer reviewed journal

Justification for type of information:

Data is from Peer reviewed journal.

Qualifier:

according to guideline

Guideline:

other: ISO (International Standardization Organization) Soil Quality- Inhibition of Reproduction ofCollembola (Folsomia candida)

Principles of method if other than guideline:

To determine toxicity of test chemical to soil micro-organism in accordance with ISO (International Standardization Organization) Soil
Quality- Inhibition of Reproduction ofCollembola (Folsomia candida) guideline

GLP compliance:

not specified

Analytical monitoring:

yes

Test organisms (inoculum):

soil

Total exposure duration:

4 wk

Test temperature:

20°C

Moisture:

90%

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass test containers
- Material, size, headspace, fill volume: 42 mm ID; 45 mm deep
- No. of organisms per vessel: 10-12 day-old juveniles
- No. of vessels per control (replicates): Five replicates
- No. of vessels per concentration (replicates): Five replicates
-Other : The test chambers were randomly placed in an incubator at 20°C with a relative humidity of90%.

Nominal and measured concentrations:

nominal : 0, 10, 18, 31, 54, 94, 164, 287, and 503 mg/kg

Reference substance (positive control):

yes

Remarks:

Prentox® carbarnate (0.05 mg kg-1)

Key result

Duration:

4 wk

Dose descriptor:

NOEC

Effect conc.:

2 444 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

respiration rate

Duration:

4 wk

Dose descriptor:

other: LOEC

Effect conc.:

2 444 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

respiration rate

Duration:

4 wk

Dose descriptor:

other: EC20

Effect conc.:

1 209 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

respiration rate

Duration:

4 wk

Dose descriptor:

EC50

Effect conc.:

1 663 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

respiration rate

Details on results:

The 4 weeks NOEC, LOEC value was determined to be 2444 mg/kg and EC20, EC50 value 1209 mg/kg , 1663 mg/kg respectively.

Reported statistics and error estimates:

Analysis of Variance (ANOVA)

Results of chemical analyses (following a 3-week weathering/aging procedure) for total Mn amended individually in SSL soil. Measured concentrations were determined using USEPA Method 200.8 and inductively coupled plasma mass spectrometry (ICP-MS).

Manganese
Nominal (mg/kg)	Measured(mg/kg)	Recovery(%)
0	94
287	386	102**
500	633	108
695	1067	140
966	1100	104
1343	1667	117
1867	2444	126
2594	2836	106
3606	3667	99
5013	5056	99

 

Validity criteria fulfilled:

yes

Conclusions:

The 4 weeks NOEC, LOEC value was determined to be 2444 mg/kg and EC20, EC50 value 1209 mg/kg , 1663 mg/kg respectively.

Executive summary:

Aim of this study was to determined the effect of test chemical on the mortality of Folsomia candida(soil micro-organism).Test was conducted for 4 week. A natural soil, Sassafras sandy loamwas used in this study to assess the toxicity oftest chemicals to F. candida.The soil was sieved through a 5mm2 mesh screen, air-dried for at least 72 h and mixed periodically to ensure uniform drying, passed through a 2-mm sieve, and stored at room temperature before use in testing. This soil was 71 % sand, 18% silt, 11 % clay, a CEC of 4.27 crnol/kg, pH of 5.0 and an organic matter content of 1.2% The culture of micro-organism was maintained in culture jars on a mixture of charcoal and plaster of Paris in the dark at 20°C and fed withcattle manure spiked with Mn at 151.7 mg/kg. The positive control used in these studies was Prentox carbarnate(0.05 mg/kg) and the Concentrations for Mn were 100, 500, 1000, 5000 and 10000 mg kg-1.Five replicates were used for each treatment concentration and controls. Nominal Mn treatment concentrations included 0, 10, 18, 31, 54, 94, 164, 287, and 503 mg kg" 1. Ten-to-twelve day-old juveniles are exposed to a range of concentrations of the test chemical added to soil. Inductively coupled plasma mass spectrometry (ICP-MS) was used to identification and detection of test chemical. Analyses of test chemical concentrations were conducted using a Perkin-Elmer 5100 PC Atomic Absorption Spectrophotometer equipped with an AS-90 auto-sampler. Test substance was extracted from soil using0.05MCaCl₂with agitation on a reciprocating shaker for 24h. Analysis of Variance (ANOVA) was used to determine the bounded No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) values for test organism. Manganese did not affect adult springtail survival at the 1667 mg/kg concentration (NOEC). Adult survival was significantly reduced at 2444 mg/kg (LOEC).The bounded NOEC for juvenile production was 1067 mg/kg and the bounded LOEC for juvenile production was 1100 mg/kg.

Description of key information

The 4 weeks NOEC, LOEC value was determined to be 2444 mg/kg and EC20, EC50 value 1209 mg/kg , 1663 mg/kg respectively.

Additional information

Following study includes experimental study for the target chemical to observe the toxicity of test chemical to soil micro-organism as follows:

Aim of this study was to determined the effect of test chemical on the mortality of Folsomia candida(soil micro-organism).Test was conducted for 4 week. A natural soil, Sassafras sandy loamwas used in this study to assess the toxicity oftest chemicals to F. candida.The soil was sieved through a 5mm2 mesh screen, air-dried for at least 72 h and mixed periodically to ensure uniform drying, passed through a 2-mm sieve, and stored at room temperature before use in testing. This soil was 71 % sand, 18% silt, 11 % clay, a CEC of 4.27 crnol/kg, pH of 5.0 and an organic matter content of 1.2% The culture of micro-organism was maintained in culture jars on a mixture of charcoal and plaster of Paris in the dark at 20°C and fed withcattle manure spiked with Mn at 151.7 mg/kg. The positive control used in these studies was Prentox carbarnate(0.05 mg/kg) and the Concentrations for Mn were 100, 500, 1000, 5000 and 10000 mg kg-1.Five replicates were used for each treatment concentration and controls. Nominal Mn treatment concentrations included 0, 10, 18, 31, 54, 94, 164, 287, and 503 mg kg" 1. Ten-to-twelve day-old juveniles are exposed to a range of concentrations of the test chemical added to soil. Inductively coupled plasma mass spectrometry (ICP-MS) was used to identification and detection of test chemical. Analyses of test chemical concentrations were conducted using a Perkin-Elmer 5100 PC Atomic Absorption Spectrophotometer equipped with an AS-90 auto-sampler. Test substance was extracted from soil using0.05MCaCl₂with agitation on a reciprocating shaker for 24h. Analysis of Variance (ANOVA) was used to determine the bounded No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) values for test organism. Manganese did not affect adult springtail survival at the 1667 mg/kg concentration (NOEC). Adult survival was significantly reduced at 2444 mg/kg (LOEC).The bounded NOEC for juvenile production was 1067 mg/kg and the bounded LOEC for juvenile production was 1100 mg/kg.