Appendix D Food Codes for NHANES - OEHHA

Scientific Review Panel Draft February, 2012
In dermal absorption studies of Se solutions, Farley et al. (1986) applied a 2.5%
selenium sulfide lotion topically overnight on human volunteers. Skin region
exposed and surface area covered were not described. Se levels in urine
following exposure were significantly increased over control levels, but
absorption was considered too slight to result in toxic effects. Repeated
overnight treatments in a few volunteers over two days did not result in Se
concentrations in the urine which were significantly higher than normal. In
another study, increased serum levels of Se could not be measured in human
volunteers that applied 2.5% selenium sulfide lotion to their torso overnight
(Kalivas, 1993). Used in shampoo as a 1% selenium sulfide concentration,
weekly use for a year did not change the normal urinary Se level (Cummins and
Kimura, 1971).
Selenium sulfide is insoluble in water and is considerably less toxic via the oral
route compared to elemental selenium or ionic forms of water-soluble selenite
and selenate salts, such as sodium selenite (Cummins and Kimura, 1971).
Lower gastrointestinal absorption of the sulfide salt was thought to be the cause
of the lower oral toxicity.
The fraction of applied dose of 75 Se internally absorbed following application of
selenous acid, a highly water soluble Se compound, onto the pelts of rats was
calculated to be 1% per day over a 9-day exposure period (Medinsky et al.,
1981).
F. 3.9.2 Discussion and Recommendation for a Selenium and Selenium
Compounds ABS
Due to the lack of quantitative data regarding dermal absorption of soil-bound Se
compounds, it is not possible to determine a chemical-specific point estimate
ABS. However, use of a 13% fractional absorption default value for Se and Se
salts for screening purposes, based on the mean of the derived ABS values for
the Hot Spots metals and semi-metals (As, Cd, Cr(VI), Pb, Hg, Ni), will likely not
underestimate dermal absorption of soil-bound Se, given that fractional
absorption of highly soluble selenous acid applied neat to the pelts of rats was
about 1% of applied dose.
F.4 Point Estimates for Dermal Absorption (ABS) of Organic
Compounds
F. 4.1 Polychlorinated Biphenyls (PCBs)
Recommended point estimate for dermal uptake from soil: 14%
F. 4.1.1 Studies Considered
F-45