November 29, 2017 

DISCLAIMER: This is a working document provided by the Centers for Disease Control and Prevention (CDC) technical support contractor, SC&A, for use in 

discussions with the National Institute for Occupational Safety and Health (NIOSH) and the Advisory Board on Radiation and Worker Health (ABRWH), including its 

Working Groups or Subcommittees. Documents produced by SC&A, such as memorandum, white paper, draft or working documents are not final NIOSH or ABRWH 

products or positions, unless specifically marked as such. This document prepared by SC&A represents its preliminary evaluation on technical issues.

NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for 

distribution. 

ISSUES RESOLUTION MATRIX FOR NIOSH-OVER-0009, “SKIN EXPOSURE”

Concern

Number Concern Description NIOSH Response Concern Resolution 

1 Concerns Related to NIOSH’s Dose Model

for Chronic Deposition of Fine Particles on 

Bare Skin (transferred to Overarching Issues 

by the SCDRR):

The derived dose of 16 mrem/yr to bare skin is 

based on unsupported and unrealistic 

assumptions, which include the following: 

(1) Daily skin contaminations for each of the 

250 workdays per year that only persist for 

8 hours;

(2) Implication that after 8 hours, each skin 

contamination is 100% removed by a standard 

daily shower; and

(3) Only bare skin is subject to contamination and 

resultant radiation exposure.

SC&A provided details of these concerns in a 

white paper titled Discussion Points Regarding 

Reconstructing Localized Skin Dose 

Associated with Direct Deposition of Uranium 

Oxide Dust and Flakes on Exposed Skin

(June 2013). 

01/07/14: SC&A agreed with the approach 

proposed by NIOSH to address fine particle 

deposition, with one exception. NIOSH found 

that uranium was not difficult to remove from 

skin and clothing, resulting in effective 100% 

removal during showering. SC&A 

recommended that NIOSH provide some 

documentation of this experience with respect 

to uranium decontamination of skin and 

clothing so that this concern can be closed. 

07/18/13 and 11/07/13: The three skin exposure

concerns were discussed, and NIOSH presented 

its approach to addressing fine particle 

deposition. 

02/11/15: In response to SC&A’s concern about 

uranium decontamination, NIOSH submitted a 

white paper titled Removal of Uranium Skin 

Contamination through Washing

(February 2015). 

02/18/15: NIOSH discussed its white paper.

02/18/15: The SCPR and SC&A agreed with 

the conclusions of the NIOSH white paper. 

The SCPR closed this concern. 
Issues Resolution Matrix for OVER-0009 2 SC&A – November 29, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

Concern

Number Concern Description NIOSH Response Concern Resolution 

2 Concerns Related to How IREP Derives

POC and Its Relevance to How Dose Is 

Assigned (transferred to Overarching Issues by 

the SCDRR): 

Given that a skin dose only occurs to a limited 

area, SC&A has concerns about the 

relationship between the derived dose and how 

IREP uses this dose to derive a POC. 

If IREP did include the baseline risk to the 

head, neck, and hands, wouldn’t that baseline 

risk be lower than the baseline risk attributed 

to the entire area of the skin? Also, if the 

baseline risk is lower, doesn’t that mean that 

the POC would increase? Further, if IREP 

included the baseline risk for the head, neck, 

and hands, it would not be necessary to reduce 

the dose, resulting in a considerably higher 

POC.

01/07/2014: Based on the discussions on this 

subject, SC&A now believes that its concern 

with respect to this matter has been resolved. 

SC&A recommends holding this concern In 

Abeyance until NIOSH issues a revision to its 

procedures confirming SC&A’s understanding 

of the protocols NIOSH plans to use, 

especially with respect to skin exposures 

beneath clothing. 

07/18/13 and 11/07/13: The IREP issue was 

discussed in concert with Concern 1. NIOSH 

provided an explanation of the relationship 

between derived dose and IREP to determine a 

POC.

04/16/14: NIOSH, SC&A, and the SCPR 

agreed that this concern has been resolved. 

The Subcommittee closed this concern. 
Issues Resolution Matrix for OVER-0009 3 SC&A – November 29, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

Concern

Number Concern Description NIOSH Response Concern Resolution 

3 Concerns Related to NIOSH’s Dose Model

for Large Uranium Flakes on Skin

(transferred to Overarching Issues by the 

SCDRR): 

Assuming that the large uranium flake

exposure scenario is plausible, at least for 

some AWE facilities in the early years, SC&A 

has the same basic questions as described in 

Concern 1 for fine particles, except now we are 

dealing with a very small area, perhaps 1 cm2, 

and relatively high dose rates (e.g., 

240 mrem/hr).

SC&A acknowledges that we have no way of 

knowing how often such events occurred or 

how long the particle remained on the skin 

before it was washed off. Nevertheless, SC&A

believes that this subject merits some 

discussion. 

01/07/14: SC&A recommends using the 

protocols described in ORAUT-OTIB-0017, 

where the skin exposure under a hypothetical 

flake is averaged over the entire surface area of 

the body. If NIOSH concurs with this basic 

strategy for addressing skin exposures to 

particles/flakes of uranium, SC&A 

recommends that this issue be closed. 

07/18/13 and 11/07/13: The large uranium flake 

issue was discussed along with Concern 1. 

NIOSH indicated that this issue was addressed in 

OTIB-0017 (shallow dose reconstruction). 

04/16/14: NIOSH, SC&A, and the SCPR 

agreed that this concern has been resolved. 

The Subcommittee closed this concern. 

AWE = Atomic Weapons Employer; IREP = Interactive RadioEpidemiological Program; POC = probability of causation; SCDRR = Subcommittee for Dose Reconstruction Reviews; 

SCPR = Subcommittee for Procedure Reviews