Manganese

Endpoint summary

Description of key information

Toxicity to soil macroorganisms :

The 16 days LOEC value was determined to be 50% for toxicity and 2 for Stimulant effect.

Toxicity to terrestrial arthropods:

The 18 weeks NOEC and LOEC value was determined to be 191 mg/kg and 267 mg/kg respectively.

Toxicity to terrestrial plants:

LOEC value of test chemical for 6 and 16 days was observed to be 2 and 4 respectively on the basis of stimulant effect.

Toxicity to soil microorganisms:

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

Toxicity to soil macroorganisms :

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

The study was conducted to determine toxicity of test chemical to soil macro-organism in accordance with ISO (1993b) methodology. The test was performed on 2 months oldEisenia foetida which were stored in commercial worm bedding with worm food. Test was performed for 16 days in polypropylene wide-mouth jars with loose fitting lids at a temperature of 20°C. Aeration was achieved by punching the lids of jar with holes to allow ventilation and oxygen supply.Ten adult earthworms were placed into 600 g(dry weight) of natural soil which were used as control or soil: sludge mixtures of different proportions i.e., 50; 25; 12.5; and 6.2% which previously hydrated to 25% water-holding capacity in 1000-ml polypropylene wide-mouth jars with loose fitting lids to minimize water evaporation and animal escape. The 16 days LOEC value was determined to be 50% for toxicity and 2 for Stimulant effect. E. foetida showed a biomass increase when exposed to the stabilized textile sludge.

Toxicity to terrestrial arthropods:

Following different studies includes experimental study for the target chemical to observe the toxicity of test chemical to terrestrial arthropods as follows:

First study was conducted to determine toxicity of test chemical to terrestrial arthropods in accordance with ISO 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants) guideline at temperature of 22± 1°C and 5.0 pH. The study was performed on Enchytraeuscrypticus for 18 weeks. A natural soil, Sassafras sandy loam [Fine-loamy, siliceous, mesic typic Hapludult] (SSL) was used in this study to determine toxicity of test chemical.The SSL soil was collected from an open grassland field on the property of the U.S. Army Aberdeen Proving Ground.The soil was sieved through a 5mm2mesh screen and air-dried for at least 72h and mixed periodically to ensure uniform drying then passed through a 2-mm sieve and stored at room temperature before use in testing. Range finding test was performed at different nominal concentrations of 100, 500, 1000, 5000 and 10000 mg/ kg test chemical.30 mg/ kg of 4-Nitrophenol was used as positive control substance. Four replicates were used for each treatment concentration and controls.

Test organism were bred in 4.3-L clear plastic boxes of 34 x 20 x l 0 cm in length filled with 2 kg (dry mass) SSL soil. The culture was kept in an incubator at 22± l °C with continuous light. Aeration was achieved by careful mixing of soil once per week. Test organisms were fed approximately twice a week with a proper amount of ground oats spread on the soil surface. Test containers were placed randomly on trays and incubated at 21±1°C with continuous light cycle. The natural manganese concentration determined in the negative control treatment was 94 mg kg-1. 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. The 18 weeks NOEC and LOEC value was determined to be 191 mg/kg and 267 mg/kg respectively.

Second study was conducted to determined the effect of test chemical on the mortality ofFolsomia candida (soil micro-organism).Test was conducted for 4 week. A natural soil, Sassafras sandy loamwas used in this study to assess the toxicity of test 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.

 

 

Toxicity to terrestrial plants:

Following study includes experimental study for the target chemical to observe the toxicity of test chemical to terrestrial plants as follows:

The study was conducted to determine toxicity of test chemical to soil macro-organism in accordance with ISO guideline. Toxicity of test chemical to plant was performed by phytotoxicity tests which were conducted with Brassica oleracea L. var. capitata (cabbage). Seeds of the test plant were supplied by the state company EPAGRI. Twenty-five cabbage seeds were sown in each pot containing 200 g of soil or soil: sludge mixture. Test was performed in three pots of disposable plastics which were 7-cm in diameter and 5-cm height and each plant test was performed in duplicate. Plants were grown under controlled conditions at a day-time temperature of 25±2°C and a nighttime temperature of 16 ±2°C with lighting of 60 mE/m2/s under a 16:8 h light: dark photoperiod. Cool-white fluorescent lamps were used to provide light. Same red-yellow Podzolic soil used as The reference (control) soil in the soil: sludge mixtures. Sludge was mixed to the soil in different proportions of 50; 25; 12.5; 6.2; and 3.1% and dechlorinated tap water was gently pipetted onto the soil surface at 66% (i.e., 64 ml) of the maximum water-holding capacity (48 ml water/100 g soil). Statistical analysis of test chemical was carried out on a microcomputer using the TOXSTAT 3.0 software. LOEC value of test chemical for 6 and 16 days was observed to be 2 and 4 respectively on the basis of stimulant effect.

Toxicity to soil microorganisms:

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.