Counseling Workers

DOE-STD-1121-98

biological half-time can be determined empirically for the affected individual, and appropriate

modification made to dose calculations.

DTPA chelation therapy for transportable plutonium can create enormous uncertainty in the use of

urine data for estimating intake. The DTPA can enhance urinary excretion of plutonium by a nominal

factor of 10 to 100. Because therapy should be given as close to the time of intake as can be reasonably

accomplished, there is little likelihood of identifying a pre-therapy baseline in urine. Methods for

evaluating chelated data have recently been described by La Bone (La Bone 1994a, 1994b) and Carbaugh

(Carbaugh et al. 1989). However, there is no standard approach. Historically, cases which were treated

with DTPA were evaluated for uptake based on urine data obtained at times unaffected by chelation (e.g.,

100 days after therapy) with the early data ignored. This approach gives an "effective" uptake estimate.

Uncertainties will still exist in the fractionation and retention factors for organs and tissues as a result of

chelation. Inhalation intake can still be assessed from early data on fecal excretion, which, compared to

data on urinary excretion, are relatively unaffected by DTPA.

In vivo measurements can be used to monitor the effectiveness of therapy for removal of 137Cs, 131I,

or other high-energy photon-emitters. These measurements can allow appropriate adjustment to be made

to whole body or organ/tissue retention functions.

Bioassay measurements take on a dual role during dose reduction therapy. In addition to their use

for dosimetry, their relative magnitude can be a valuable indication of the effectiveness of therapeutic

actions. In some cases, crude measurements may be very valuable to indicate the efficacy of therapy;

however, their value for the final intake and dose assessments may be quite limited.

Dose reduction therapy places great strains on an internal dosimetry/bioassay program. The

dosimetrist must recognize the many potential impacts on bioassay measurements caused by therapy and

factor these into the data interpretation. Where normal dosimetry would call for emphasis on a set of

measurements which might be significantly affected by therapy, good practice suggests that estimates be

obtained by as many alternate methods as reasonable and wise judgement exercised in final interpretation.

10.6 COUNSELING WORKERS

Counseling of workers who have incurred intakes of radioactivity should be performed to clarify the

significance (or insignificance) of an intake and provide workers with the information needed to help

resolve any concerns about medical or radiological effects. Such counseling is also an opportunity to

discuss any needs for long-term follow-up bioassay measurements or dose reevaluations. Documentation

of counseling may take the form of a memo to file, letter to worker, or simply a checklist of subjects

discussed. Documented acknowledgment of the counseling session by the worker is desirable. However,

the need for such acknowledgment does not justify any effort beyond that normally used for routinely

reporting medical exam or bioassay measurement results.

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