Trimanganese tetraoxide

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Conducted to a reasonable scientific standard.

Data source

Reference

Reference Type:

publication

Title:

Are Current Biomarkers Suitable for the Assessment of Manganese Exposure in Individual Workers

Author:

Apostoli P, Lucchini R & Alessio L

Year:

2000

Bibliographic source:

American Journal of Industrial Medicine, 37: 283-290

Materials and methods

Study type:

cross sectional study

Endpoint addressed:

neurotoxicity

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Environmental and biological monitoring (blood and urine) of 94 employees in a ferroalloy production exposed to Mn oxides (MnO2 and Mn3O4). Results compared to control group not exposed to Mn.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Trimanganese tetraoxide

EC Number:

215-266-5

EC Name:

Trimanganese tetraoxide

Cas Number:

1317-35-7

Molecular formula:

Mn3O4

IUPAC Name:

trimanganese tetraoxide

Method

Details on study design:

METHOD OF DATA COLLECTION
- Type: Clinical tests
- Details: Venous blood sample of 5 ml and a spot urine sample collected at the end of the shift.

STUDY POPULATION
- Selection criteria: exposed to Mn oxides or not during typical working shift
- Total number of subjects participating in study:
- Sex/age/race: male, age = 40.2 ± 8.3 years

COMPARISON POPULATION
- Type:Control or reference group
- Details: Maintenance workers with comparable habits but no Mn exposure


HEALTH EFFECTS STUDIED
- Disease(s): not reported

Exposure assessment:

measured

Results and discussion

Results:

FINDINGS
Urinary Mn (MnU) concentrations in the exposed group exhibited a five-fold increase over the controls. Blood Mn (MnB) levels were found to be twice as high in the exposed than in the controls.

Significant differences were observed between all three subgroups and the controls for MnU and MnB levels. Significant differences were also observed between all the three subgroups considered.

Confounding factors:

Smoke, alcohol, tea and coffee consumers. MnO2 in same facility.

Strengths and weaknesses:

Not reported

Any other information on results incl. tables

TABLE 1: Mean MnB Values (in µg/L) in the different Subgroups Based on MnA Levels: F-value: 37.94, P < 0.0001

Subgroup	N	Mean MnB	S.D.
Low exposure	34	8.65	3.18
Mid exposure	29	10.93	3.25
High exposure	31	11.39	4.61
Controls	89	5.99	1.73

Table 2: Mean MnU Values (in µg/L) in the Different Subgroups Based on MnA Levels: F-value: 46.26, P < 0.0001

Subgroup	N	Mean MnU	S.D.
Low exposure	34	3.12	1.48
Mid exposure	29	4.79	2.87
High exposure	31	7.04	4.72
Controls	89	1.19	1.41

Applicant's summary and conclusion

Conclusions:

These results confirm that MnB and MnU can discriminate groups of occupationally exposed workers from groups of none exposed subjects. MnB is also related to the intensity of external exposure on a linear relationship, but given a high variability, it is not suitable for individual biological monitoring. Therefore, further research should focus on more accurate biomarkers of Mn exposure.