PNNL

Abstract

The recent interest in cumulative exposure assessment has highlighted the potential importance of dermal absorption to total systemic exposure. The extent and rate at which penetration through the skin occurs depends upon a large number of biological and environmental variables. The skin can function as a barrier, has some metabolic activity, contains multiple appendages and cell types, and is the largest organ of the body. Skin absorption is dictated by skin physiology, site of exposure, and exposure area, and it is species-specific. The extent of absorption through skin also is site-specific (Wester et al., 1984). In addition, exposure variables such as concentration, media (e.g., soil vs. water), temperature, and occlusion (which prevents volatilization or loss of the compound and may increase the hydration of the skin) compound the problem of assessing the amount of chemical absorbed. Taken together, these characteristics impose many challenges to estimating the contribution of dermal absorption to systemic dose.