Radioactive contaminant permeation through skin: current understanding

Area of Science:

• Radiological protection
• Dermatology
• Toxicology

Background:

• Understanding radiochemical permeation through skin is crucial for assessing risks from contamination.
• Previous studies have investigated various radionuclides and skin conditions, yielding diverse results.

Purpose of the Study:

• To review and synthesize current knowledge on radiochemical permeation through intact and damaged skin.
• To identify factors influencing radionuclide skin absorption and compare different experimental models.

Main Methods:

• Review of studies involving human volunteers, animal models, and accidental contaminations.
• Analysis of permeation data for various radiochemicals (e.g., plutonium, americium, iodine, technetium, uranium).
• Comparison of in vivo and in vitro methods and different skin models.

Main Results:

• Intact skin shows low fractional absorption (<0.1% to <1%) for most studied radiochemicals.
• Chemically injured skin and chelating agents (e.g., DTPA) significantly increase permeation (1-10%).
• Iodine-125 and technetium-99m pertechnetate exhibit high permeation (up to 60%) through intact pig skin; uranium results are inconclusive.
• Stratum corneum is the primary barrier; its damage drastically enhances permeation.

Conclusions:

• Skin permeability varies greatly depending on the radiochemical's properties and the skin's integrity.
• Animal skin models may overestimate human skin permeability.
• Further research is needed to elucidate the mechanisms of radiochemical skin transport.