Tantalum

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

not reported

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Report with an insufficient level of information to assess the findings presented.

Data source

Reference

Reference Type:

publication

Title:

Tantalum inhalation and pulmonary function

Author:

Smith P, Stitik F, Smith J, Rosenthal R, Menkes H

Year:

1977

Bibliographic source:

American Review of Respiratory Disease, Vol. 115, No. 4, April 1977 p 378

Materials and methods

Study type:

study with volunteers

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The effects of tantalum inhalation was studied in 14 volunteers. During the study, tantalum aerosol was inhaled through an oropharyngeal tube. Pulmonary function was tested before and within 15 minutes of inhalation. Roentgenograms of the subjects were taken and measurements of closing volume, closing capacity, total lung capacity and residual volume were taken. Specific airway conductance (SGaw) and forced expired volume (FEV1) were determined.

GLP compliance:

not specified

Remarks:

(not reported)

Test material

Test material information

Constituent 1

Reference substance name:

Tantalum

EC Number:

231-135-5

EC Name:

Tantalum

Cas Number:

7440-25-7

Molecular formula:

Ta

IUPAC Name:

tantalum

Details on test material:

- Name of test material (as cited in study report): tantalum aerosol

Method

Type of population:

not specified

Subjects:

14 normal volunteers.

Route of exposure:

inhalation

Reason of exposure:

intentional

Exposure assessment:

not specified

Details on exposure:

Tantalum aerosol was inhaled through an oropharyngeal tube. No further information provided.

Results and discussion

Any other information on results incl. tables

None of the groups showed changes in closing volume, closing capacity, slope of phase III, total lung capacity, or residual volume. In groups 2 and 3, neither specific airway conductance (SGaw) nor forced expired volume in one second (FEV1) changed significantly; however, bothe SGaw and FEV1 fel significantly in Group 3: 25 -45% and 9 -13% respectively. Even though there was no change in FEV1 with air in Group 2, the FEV1 with helium in all four subjects tested in Group 2 fell 2 -5%. To test whether subjects in Group 3 had more reactive airways, challenges with metacholine were performed in all 3 groups. No significant differences between groups were detected.

Applicant's summary and conclusion

Conclusions:

During the course of the study the airway response to tantalum was seen to be variable in normal volunteers and thought, in part, to be related to depth of particle deposition. Pulmonary changes (SGaw, FEV1) were correlated with bronchoconstriction seen on roentgenograms, although changes in FEV1 with helium in Group 2 suggest that small airways constrict distal to those visualised by tantalum. Methacholine failed to detect differences in airway reactivity and thus failed to predict airways response to tantalum inhalation. This indicated that the airway responsiveness to an inert metal seen in Group 3 is not related to an individual's response to vagal agonists.

Executive summary:

The effects of tantalum inhalation was studied in 14 volunteers. During the study, tantalum aerosol was inhaled through an oropharyngeal tube. Pulmonary function was tested before and within 15 minutes of inhalation. Roentgenograms of the subjects were taken and measurements of closing volume, closing capacity, total lung capacity and residual volume were taken. Specific airway conductance (SGaw) and forced expired volume (FEV1) were determined. During the course of the study the airway response to tantalum was seen to be variable in normal volunteers and thought, in part, to be related to depth of particle deposition. Pulmonary changes (SGaw, FEV1) were correlated with bronchoconstriction seen on roentgenograms, although changes in FEV1 with helium in Group 2 suggest that small airways constrict distal to those visualised by tantalum. Methacholine failed to detect differences in airway reactivity and thus failed to predict airways response to tantalum inhalation. This indicated that the airway responsiveness to an inert metal seen in Group 3 is not related to an individual's response to vagal agonists.