pentapotassium 2,2’,2’’,2’’’,2’’’’-(ethane-1,2-diylnitrilo)pentaacetate

Exposure related observations in humans: other data

Administrative data

Endpoint:

exposure-related observations in humans: other data

Type of information:

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

Adequacy of study:

supporting study

Study period:

1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published data, information on methods and results is sufficient to make an assessment

Data source

Reference

Reference Type:

publication

Title:

1976 Hanford American Exposure Incident: in vivo measurements

Author:

Palmer HE & Rieksts GA

Year:

1983

Bibliographic source:

Health Phys., vol. 45, 893-910

Materials and methods

Type of study / information:

Detailed external measurements were made of internally deposited 241Am in a nuclear chemical operator involved in an americium exposure accident at the Hanford plant. Despite some interference from high-level external contamination, quantitative measurements of the 241Amercium (AM) content in the lung, liver and bones were made starting on the third day after the accident. The rate of excretion of 241Am from these organs was determined. The distribution over the total length of the body was also determined.

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

None specified

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

N-carboxymethyliminobis(ethylenenitrilo)tetra(acetic acid)

EC Number:

200-652-8

EC Name:

N-carboxymethyliminobis(ethylenenitrilo)tetra(acetic acid)

Cas Number:

67-43-6

Molecular formula:

C14H23N3O10

IUPAC Name:

2-[bis[2-(bis(carboxymethyl)amino)ethyl]amino]acetic acid

Details on test material:

- Name of test material (as cited in study report): Diethylenetriaminepentaacetate (DTPA)

Method

Ethical approval:

not applicable

Details on study design:

Detailed external measurements were made of internally deposited 241Am in a nuclear chemical operator involved in an americium exposure accident at the Hanford plant. Despite some interference from high-level external contamination, quantitative measurements of the 241Am content in the lung, liver and bones were made starting on the third day after the accident. The rate of excretion of 241Am from these organs was determined. The 241Am embedded in the skin of the face and head was carefully mapped. The distribution over the total length of the body was also determined. Linear and rectilinear scanners, y cameras, large and small scintillation detectors, proportional counters, and Si(Li) and intrinsic germanium detectors were used to evaluate the internal deposition. Methods of calibration for quantitative measurement included simulation of the 241Am activity in both phantom and cadaver parts.

Exposure assessment:

measured

Details on exposure:

Not applicable

Results and discussion

Results:

See the remarks below.

Any other information on results incl. tables

Americium-241 penetrated the skin of the subject's neck and head, both in contaminated flying debris from the explosion and as an ion in the concentrated nitric acid solution that was sprayed onto his skin. On the 75th day after the accident, an attempt was made to detect the 3.3 keV Np M X-ray with a Si(Li) detector 5 mm thick-by-3 cm' in area. These X-rays are emitted in about the same abundance as the L X-rays, but are essentially all absorbed within 0.3 mm of tissue. None of the 4.4-cm diam areas monitored on the right side of the face showed any evidence of the 3.3 keV photopeak, indicating that the major portion of the activity was deeper than 0.3 mm. From the ratio of the 14 keV X-ray to the 60 keV y -ray peak, the average depth of the activity was determined to be 0.7 mm.

 

The 3.3 keV M X-rays were measurable over the left eyeball (Pa80), which indicated that a small amount of activity existed just below the tissue surface.

 

Biopsy of facial tissue

Ninety-four days after the accident, a sample of skin and subcutaneous tissue 4 mm in diam and 4 mm thick was removed from each side of the subject's face in the upper cheek area (13r83; Ha83) and the total radioactivity in each sample was measured immediately. The tissue from the right side contained 2.8 nCi, which is equivalent to 21.5 nCi/em' of skin area, and the tissue from the left side contained only 0.012 nCi or 0.4% as much as tissue from the right side.

 

Applicant's summary and conclusion

Conclusions:

The in vivo measurements made in this accident case were very useful in assessing the need for, and the effects of, DTPA therapy for removal of the 241Am from the liver and other tissue; in determining the need for surgical removal of some of the radioactive debris embedded in the skin; and for assessing the radiation dose to various organs and parts of the body.

Executive summary:

Detailed external measurements were made of internally deposited ²⁴¹Am in a nuclear chemical operator involved in an americium exposure accident at the plant.Despite some interference from high-level external contamination, quantitative measurements of the ²⁴¹Am content in the lung, liver and bones were made starting on the third day after the accident. The rate of excretion of ²⁴¹Am from these organs was determined. The ²⁴¹Am embedded in the skin of the face and head was carefully mapped. The distribution over the total length of the body was also determined. Linear and rectilinear scanners, y cameras, largeand small scintillation detectors, proportional counters, and Si(Li) and intrinsic germanium detectors were used to evaluate the internal deposition. Methods of calibration for quantitative measurement included simulation of the ²⁴¹Am activity in both phantom and cadaver parts.

The in vivo measurements made in this accident case were very useful in assessing the need for, and the effects of, DTPA therapy for removal of the ²⁴¹Am from the liver and other tissue; in determining the need for surgical removal of some of the radioactive debris embedded in the skin; and for assessing the radiation dose to various organs and parts of the body.

 

These measurements also provided encouragement and assurance to the subject since hecould monitor the almost daily loss of internally deposited ²⁴¹Am from the liver and lungs and the slower loss of radioactivity from the facial tissue.