Manganese

Biodegradation in soil

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in soil, other

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data for the target chemical is summarized based on the structually and functionally similar read across chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: refer below principle

Principles of method if other than guideline:

WoE study was prepared for toxicity of test chemical by considering WoE 2 and 3

GLP compliance:

not specified

Test type:

other: 2: Laboratory; 3: Field trial

Radiolabelling:

yes

Remarks:

2: 14C-mancozeb

Oxygen conditions:

other: 2: Aerobic (20ppm ) sequential aerobic/anaerobic(10ppm); 3: Aerobic

Soil classification:

other: No data

Soil type:

silt loam

Soil type:

other: moist plough

pH:

> 5.5 - < 6.5

Details on soil characteristics:

2:
Soil type: silt loam soil (nonsterile and sterile)

Duration:

3 mo

Duration:

6 wk

Initial conc.:

20 ppm

Based on:

test mat.

Initial conc.:

10 ppm

Based on:

test mat.

Parameter followed for biodegradation estimation:

not specified

Temp.:

11-16 deg C

Details on experimental conditions:

3:
Other: 2-4% humus

Key result

Soil No.:

#1

% Degr.:

90

Sampling time:

6 wk

Remarks on result:

other: not specified

Key result

DT50:

> 2 d

Temp.:

23 °C

Remarks on result:

other: Aerobic no sterile soil

Remarks:

20 ppm

DT50:

> 8 d

Remarks on result:

other: Anaerobic non sterile soil

Remarks:

10 ppm

Transformation products:

not specified

Details on results:

The approximate half-lives of test chemical in nonsterile aerobic and anaerobic soils observed to be less than 2 days and 8 days, respectively and Percent biodegradation of test chemical was observed 90% in 6 wk. On the basis of above observation is is concluded that the test chemical is readily biodegradable in soil.

2:

The mineralization of test chemical was observed to be degradates to carbon dioxide only occurred in nonsterilized soils and no detectable carbon dioxide was released from sterile soils. It is indicating that mineralization was mainly conducted by microorganisms.

Conclusions:

The approximate half-lives of test chemical in nonsterile aerobic and anaerobic soils observed to be less than 2 days and 8 days, respectively and Percent biodegradation of test chemical was observed 90% in 6 wk. On the basis of above observation is is concluded that the test chemical is readily biodegradable in soil.

Executive summary:

Data available for the structurally similar and closely related read across chemicals study has been reviewed to determine the biodegradation of test chemical in soil. The studies are as mentioned below:

In first study the degradation of 20 ppm and 10 ppm conc. of test chemical was investigated on silt loam soil (no sterile and sterile) under aerobic and sequential aerobic/anaerobic conditions at an average temperature of 23⁰±0.60⁰C. The mineralization of mancozeb was observed to be degradates to carbon dioxide only occurred in nonsterilized soils and no detectable carbon dioxide was released from sterile soils. It is indicating that mineralization was mainly conducted by microorganisms. The approximate half-lives of mancozeb in nonsterile aerobic and anaerobic soils observed to be less than 2 days and 8 days, respectively. On the basis of above observation is is concluded that the test chemical is readily biodegradable in soil.

Second study was conducted to determine the biodegradation of test chemical in soil. The test was performed in field for 6 weeks. Approximately 90% of test chemical was observed to be degraded under pH of 5.5-6.5 and medium air temperature of 11-16⁰C. On the basis of above observation the test chemical concluded to be readily degradable.

On the basis of above observation is is concluded that the test chemical is readily biodegradable in soil.

Description of key information

Study was conducted to determine biodegradation of test chemical in soil . The approximate half-life  of test chemical  in nonsterile aerobic and anaerobic soils observed to be  less than 2 days and 8 days, respectively. On the basis of above observation is is concluded that the test chemical is readily biodegradable in soil.

Key value for chemical safety assessment

Half-life in soil:

2 d

at the temperature of:

23 °C

Additional information

Data available for the structurally similar and closely related read across chemicals study has been reviewed to determine the biodegradation of test chemical in soil. The studies are as mentioned below:

In first study the degradation of 20 ppm and 10 ppm conc. of test chemical was investigated on silt loam soil (no sterile and sterile) under aerobic and sequential aerobic/anaerobic conditions at an average temperature of 23°±0.600C. The mineralization of mancozeb was observed to be degradates to carbon dioxide only occurred in nonsterilized soils and no detectable carbon dioxide was released from sterile soils. It is indicating that mineralization was mainly conducted by microorganisms. The approximate half-lives of mancozeb in nonsterile aerobic and anaerobic soils observed to be less than 2 days and 8 days, respectively.  On the basis of above observation is is concluded that the test chemical is readily biodegradable in soil.

Second study was conducted to determine the biodegradation of test chemical in soil. The test was performed in field for 6 weeks. Approximately 90% of test chemical was observed to be degraded under pH of 5.5-6.5 and medium air temperature of 11-160C.  On the basis of above observation the test chemical concluded to be readily degradable.

On the basis of above observation is is concluded that the test chemical is readily biodegradable in soil.