NIOSH-OVER-0009

Skin Exposure

Report from the Subcommittee for Procedure Reviews (SCPR)

Presented to the

Advisory Board on Radiation and Worker Health

April 11, 2018

Oak Ridge, Tennessee

1
Overarching Issues

• Represents a categorization of observations/findings that arise during 

dose reconstruction reviews or technical guidance document reviews, 

which will impact numerous sites.

• NIOSH-OVER-0009 specifically addresses SC&A’s concerns regarding 

the modeling of fine and large particle deposition on the skin.

2
Concern 1: Concerns Related to NIOSH’s Dose Model for Chronic 

Deposition of Fine Particles on Bare Skin (transferred to Overarching 

Issues by the SCDRR)

• SC&A’s concern involved a derived dose of 16 mrem/year to bare skin that 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

3) Only bare skin is subject to contamination and resultant radiation exposure

• NIOSH discussed its approach for addressing fine particle deposition to the 

satisfaction of SC&A, except for assumptions regarding the ease with which uranium 

could be removed from skin and clothing. 

• NIOSH prepared a white paper (February 2015), which assessed the literature for 

articles that qualitatively and quantitatively supported the removal of uranium by 

washing with soap and water.

• Resolution as of February 18, 2015: SC&A and the SCPR found NIOSH’s conclusions 

acceptable, and the SCPR closed this concern. 3
Concern 2: Concerns Related to How IREP Derives Probability of 

Causation (POC) and Its Relevance to How Dose Is Assigned 

(transferred to Overarching Issues by the SCDRR)

• SC&A’s concern involved the relationship between the derived dose and 

how IREP uses this dose to derive a POC, given that the skin dose only 

occurs to a small area.

• The IREP issue was discussed at the 07/18/13, 11/07/13, and 04/16/14 

SCPR teleconferences. To satisfy SC&A’s concern, NIOSH did the following:

• Provided an explanation of the relationship between derived dose and IREP to 

determine a POC. 

• Identified that specific guidance for dealing with non-uniform exposure to the skin 

has been incorporated into OTIB-0017. 

• Consulted with SENES to confirm OTIB-0017 guidance was appropriate.

• SC&A and the SCPR concurred with this response. 

• Resolution as of April 16, 2014: The SCPR closed this concern. 4
Concern 3: Concerns Related to NIOSH’s Dose Model for Large 

Uranium Flakes on Skin (transferred to Overarching Issues by the 

SCDRR)

• SC&A had the same basic questions as described in Concern 1, but for 

deriving doses for the skin deposition of large uranium flakes. 

• The large uranium flake issue was discussed at the 07/18/13, 

11/07/13, and 04/14/16 SCPR teleconferences. SC&A recommended 

using OTIB-0017 protocols, where the skin exposure under a 

hypothetical flake is averaged over the entire surface area of the 

body.

• NIOSH and the SCPR concurred with this response.

• Resolution as of April 14, 2016: The SCPR closed this concern. 

5
Questions?

6