Appendix D Food Codes for NHANES - OEHHA

Scientific Review Panel Draft February, 2012
receptor fluid; 0.33% in skin) after soap and water wash. While the authors did
not speculate as to the reduced in vitro dermal absorption compared to monkey
in vivo absorption, Kao (1990) noted that both elapsed time from death to harvest
of tissues and treatments and storage of the cadaver could have resulted in a
large variability in skin permeability.
Dermal absorption of radiolabeled soluble arsenic (as H3 73 AsO4) freshly applied
or aged in two different soils was determined in vitro through dermatomed pig
skin cut 200 µm thick (Abdel-Rahman et al., 1996; Abdel-Rahman et al., 1999).
Soil types included a sandy soil with 4.4% organic matter and a clay soil with
1.6% organic matter, with no apparent sieving before application. Arsenic was
applied to skin for 16 hrs either alone in ethanol vehicle, immediately after the
addition of 30 mg of the soils to skin, or after aging for 3 months in each soil. Soil
loading was calculated to be about 47 mg/cm 2 . Applying soil to skin and then
applying the arsenic does not allow time for arsenic-soil equilibrium. This method
of application allows for direct contact of skin with arsenic or vehicle and not from
soil, leading to an overestimation of the fractional absorption (Spalt et al., 2009).
In addition, monolayer coverage was probably exceeded with a soil loading of 47
mg/cm 2 .
With arsenic freshly added to soil, 0.2% of the arsenic penetrated the skin to
receptor fluid from both soil types (Abdel-Rahman et al., 1996; Abdel-Rahman et
al., 1999). Total dermal absorption including arsenic retained in skin was 10.0
and 6.0% from the sandy and clay soils, respectively. In comparison, pure
arsenic found in receptor fluid and retained in skin was 0.4 and 44.2%,
respectively. In aged sandy and clay soil, 0.2 and 0.1% arsenic was found in the
receptor fluid, respectively. Total dermal absorption in the aged soils was 1.5
and 0.8% from sandy and clay soils, respectively.
Radiolabeled sodium arsenate was applied in vitro to the skin of mice for 24 hrs
as a solid compound, in an aqueous solution, or as an aqueous solution in sandy
soil (Rahman et al., 1994). Soil was sieved to