Tantalum

Repeated dose toxicity: other routes

Administrative data

Endpoint:

sub-chronic toxicity: other route

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study data from literature relating to non-standard test methods. The experiment was conducted in accordance with accepted scientific principles.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Depleted Uranium Distribution and Toxicology in a Rodent Model

Author:

Pellmar TC, Hogan JB, Benson KA & Landauer MR

Year:

1998

Bibliographic source:

AFRRI Special Publication 98(3): 7-9

Reference 2

Reference Type:

publication

Title:

Health Effects of Depleted Uranium Fragments

Author:

Armed Forces Radiobiology Research Institute

Year:

1998

Bibliographic source:

Livengood DR (ed) An Armed Forces Radiobiology Research Institute Workshop

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

A study was conducted to investigate the toxicity associated with depleted uranium exposure. Rats were exposed to the metal through implantation; tantalum was selected to be a chemically inert control.

GLP compliance:

not specified

Limit test:

yes

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

Test material form:

solid: pellets

Details on test material:

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

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Administration / exposure

Route of administration:

other: implantation

Vehicle:

unchanged (no vehicle)

Details on exposure:

Tantalum pellets were surgically implanted into the gastrocnemus muscle of both hindlimbs of the rats.

Duration of treatment / exposure:

Data were analysed at 30 days and 6 months after implantation.

Frequency of treatment:

A single surgical implantation procedure took place; the implanted tantalum remained in the test animals for 6 months.

Doses / concentrations

Remarks:

Doses / Concentrations:
Each animal had 20 1 x 2 mm tantalum pellets implanted.

Control animals:

yes, concurrent no treatment

Details on study design:

The study was conducted to evaluate kidney, behavioural and neural toxicity associated with implanted depleted uranium pellets. In addition, assess tissues were assessed for histological changes and uranium content.
Two control groups were used as part of this study: one was a completely non-surgical control group and the other was implanted with tantalum pellets.

Examinations

Observations and examinations performed and frequency:

Data were analysed at 30 days and 6 months after implantation.

-The distribution of uranium and tantalum were measured in tissues after 6 months.
-Changes in bodyweight were continually monitored for 28 weeks.
-Behavioural and neurotoxicity were evaluated through a functional observational battery, locomotor activity grip strength, passive-avoidance learning, peripheral nerve conduction velocity and hippocampal field potential recordings.

Results and discussion

Results of examinations

Body weight and weight changes:

no effects observed

Behaviour (functional findings):

no effects observed

Details on results:

Examination of the pellets in situ revealed no fibrous tissue adhering to the pellets after implantation with tantalum.
The distribution of the metals throughout the tissues was examined; after 6 months the levels of tantalum found were negligible.

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

During the course of the study, examination of the implanted pellets in situ revealed no fibrous tissue adhering to the tantalum pellets. No other effects with tantalum were recorded.

Executive summary:

A study was conducted to investigate the toxicity associated with depleted uranium exposure. Pellets of the metals were surgically implanted into the gastrocnemus muscle of both hindlimbs of male Sprague-Dawley rats. The implantation of tantalum was selected to be a chemically inert control, in addition to a non-surgical control group. Data were analysed at 30 days and 6 months after implantation.

Parameters investigated were kidney, behavioural and neural toxicity. Also, tissues were assessed for histological changes and uranium content.

Bodyweight was continually monitored for 28 weeks. Behavioural and neurotoxicity were evaluated through a functional observational battery, locomotor activity grip strength, passive-avoidance learning, peripheral nerve conduction velocity and hippocampal field potential recordings.

After 6 months the levels of tantalum found distributed through tissue were negligible. Examination of the pellets in situ revealed no fibrous tissue adhering to the pellets after implantation with tantalum. Bodyweight gain was as expected and comparable to the non-surgical control. No other effects were noted for the animals implanted with tantalum.