Occupational Intakes of Radionuclides Part 1

Draft document: Occupational Intakes of Radionuclides Part 1
Submitted by Eugene H. Carbaugh, Pacific Northwest National Laboratory
Commenting on behalf of the organisation

I am pleased with the comprehensive nature of the report.  I offer two specific technical comments.

1.       There seems to be a discrepancy between the breathing rate assumption used for a Reference Worker (1.2 m3 h-1 during an 8-h working day, lines 420-421 and 860-861) and the use of a sex-averaged breathing rate of 1.1 m3 h-1) for calculating DACs (line 1458-1461).  It seems the same value should be used in both places.  My personal preference would be to stick with the long-standing 1.2 m3 h-1 rate rather than modify the DAC calculation, and that preference seems supported by discussion in Section 3.7.3, lines 3543-3549. 

2.   The issue of normalizing partial day samples to 24-h samples is briefly addressed in lines 3632-3644).  Although volume and mass normalization are addressed much later in the report (lines 4334-4346), the only method of normalization mentioned in this initial discussion is creatinine concentration, which could possibly be interpreted as a specifically preferred method.   This discussion should be expanded.   Other methods that have been used include time (i.e., length of actual sampling interval), volume, and specific gravity.  Limiting the discussion to creatinine implies unwarranted confidence in that method.  Studies by Jackson (1966), Kim (1995), Boeniger et al. (1993), and Graul and Stanley (1982) have suggested that creatinine and specific gravity normalization do not provide improved confidence over normalization by time or volume, and creatinine and specific gravity can pose additional measurements (and cost) beyond those commonly performed.  (Full citations provided on request or can be found in Section 2.10 of Methods and Models of the Hanford Internal Dosimetry Program, available at  http://www.pnl.gov/main/publications/external/technical_reports/PNNL-15614rev1.pdf )