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Exposure related observations in humans: other data

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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented publication

Data source

Reference
Reference Type:
publication
Title:
Measurement of Internal Contamination with Radioactive Caesium released from the Chernobyl Accident and Enhanced Elimination by Prussian Blue.
Author:
Tang, M., Gong, Y., Shen, C., Ye, C & Wu, D.
Year:
1988
Bibliographic source:
J. Radiol. Prot.8, 1, 25-28.

Materials and methods

Type of study / information:
A serious accident occurred in the number 4 reactor of the Chernobyl Nuclear Power Station on 26th April 1986 as a result of which considerable quantities of radioactive materials were released to the environment. Fifteen members of a Chinese Foreign Exhibition Group were working at Sofia and Profdef, Bulgaria from 18th April to 23rd May 1986. During 5-10 May they occasionally found a rise in gamma- background dose rate with a FD-301 dosimeter, which indicated that it might be contaminated with radioactive material released from the Chernobyl-4 reactor. Fifteen internally contaminated Chinese subjects were monitored from 12th June to 21st June in Beijing. This paper describes the results of measurements and of the effects of Prussian blue (Ferric ferrocyanide) on the rate of elimination of radiocaesium.
Endpoint addressed:
not applicable
Principles of method if other than guideline:
This paper describes the results of measurements and of the effects of Prussian blue (ferric ferrocyanide) on the rate of elimination of radiocaesium in humans.
GLP compliance:
no

Test material

Constituent 1
Reference substance name:
Prussian blue
IUPAC Name:
Prussian blue
Details on test material:
- Name of test material (as cited in study report): Prussian blue

Method

Ethical approval:
not specified
Details on study design:
The gamma activities of radionuclides in the 15 subjects were measured with the low background whole body counter in the laboratory. The characteristics of this counter where as follows:

1) The spectrometric resolution for 137Cs was 8.9%.
2) The minimum detectable activity was 38- 48 Bq of 137Cs and 3 Bq 131I at the 99% confidence level.
3) The 137Cs background activity in 80 male Beijing residents (age range of 20 -49) was 58 -65 Bq.
4) The non-uniformity of response is less than 20% for constant speed scanning.
5) The long time stability of background was better than 4%.

Utilising a 9 x 4 inch NaI (T1), the measurement were performed in two ways; a single crystal measurement at the site of the thyroid, and a single, constant scanning speed detector moving along the length of the body. The counts were obtained by subtracting the counts in non-contaminated cases from the counts obtained from contaminated cases. The activities of radionuclides in the body were calculated by a matrix inversion method using calibration factors. The biological half-life of radiocaesium in the body was observed in three volunteers.

Prussian blue (PB) was given to the three volunteers to investigate the effect on caesium excretion. One gram of Prussian blue was given three times per day, for a six day course. Three courses were given with a time interval of 6 days between each subsequent course. During the investigation period of 114 -141 days after contamination, the biological half-life of radiocaesium was observed and compared with that of control period.
Exposure assessment:
measured

Results and discussion

Results:
From the biological half-life it can be seen that the body retention of radiocaesium declined more rapidly following Prussian blue administration than in those of controls. It is evident that shortening of biological half-life results in a more pronounced decrease of cumulative activity of radiocaesium in the body. The percentage excess of cumulative activity during the period of 114- 141 days after internal contamination was calculated by using each subject's own biological half-life by means of the following equation:
Excess decrease of cumulative activity (%)
= A -B/ A x 100
where A is the cumulative activity without treatment and B is the cumulative activity with treatment.
The results in table 3 indicates that the cumulative activities decrease significantly (p<0.05), showing that Prussian blue treatment can enhance the excretion of radiocaesium.

Any other information on results incl. tables

Table 1. Internal contamination of 15 Chinese subjects, resident in Bulgaria at the time of the Chernobyl nuclear reactor accident.

Subject

Date of Measurement

Activity in body (Bq+)

Intake estimated (Bq)

137Cs

134Cs

137Cs

134Cs

ZN

12 June 1986

700

360

950

500

FU

19

470

370

660

550

GO

17

600

340

850

500

MU

18

470

380

660

560

CE

20

440

300

640

450

HO

21

430

330

620

490

CN

19

340

300

490

440

YU

18

390

300

550

430

TN

20

840

630

1200

930

HU

18

280

170

390

260

EI

19

350

240

500

350

SO

19

440

250

620

270

WE

19

320

210

460

300

JA

18

370

260

530

380

LI

17

68

110

95

170

+ The relative errors of all the, measured values, except LI, are in the range of 5-12%, while for LI the figures are 30% for 137Cs and 31% for 134Cs.

 

  

Table 2. Biological half-life of 137Cs and 134Cs in man and the effect of oral administration of Prussian blue (PB).

 

Subject

Biological half-life+(days)

137Cs

134Cs

Control

PB Administration

Control

PB Administration

YN

71

43

46

23

ZN

54

48

42

33

MU

60

29

51

++

+The relative errors of biological half-life were in the range of 16-30%

++134Cs activity in the body was near to the minimum detectable level.

 

Table 3. Diminution of radiocaesium body burden in man by Prussian Blue (PB).

 

Subject

Radiocaesium

Cumulative activity

Activity decreased (%)

No PB

PB Administration

YN

134Cs

4400

3600

18

137Cs

9900

9100

8

ZN

134Cs

2100

2000

5

137Cs

5700

5600

2

MU

137Cs

4200

3500

17

 

Table 4. Effect of Prussia Blue on the enhancement of the elimination of radiocaesium in man.

 

  Start of admin. Of PB (days after contam.)

Cases

Admin. Program

Biological half-life (day)

Reference

Control

PB Admin

114

1

1.0 g x 3/d for 6d

71

43

Present study (1988)

 

1

3 courses

54

48

 

 

1

 

60

29

 

67

1

1.0 g x 3/d for 5 d. 2 courses

110

70

Ye Gen-yao et al (1981)

35

1

1.0 g x 3/d for 100 d

124

38

Ma Ru-Wei et al.

35

1

1.0 g x 3/d for 75 d

54

39

 

35

1

1.0 g x 3/d for 82 d

61

25

 

35

1

1.0 g x 3/d for 100 d

36

17

 

35

1

1.0 g x 3/d for 100 d

36

16

 

12

1

0.2 g x 10/d for 5 d. 2 courses

140

50

C R Richmond (1967)

300

1

1.0 g x 3/d

115

40

K Madhaus (1966)

300

1

1.0 g x 3/d

110

40

 

 

 

 

 

 

Applicant's summary and conclusion

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