ABSTRACT
The U.S. Environmental Protection Agency (EPA) defines exposure as the contact of
a contaminant with the outer boundary of the body (skin and openings such as
mouth and nostrils) (1). Humans are exposed dermally to environmental contami-
nants in water, soil, and air, or as pure chemicals or chemical mixtures in consumer
products or in occupational settings. Because the Agency utilizes exposure
information to estimate local and systemic risks associated with chemical contact,
the focus of dermal exposure includes absorption of a chemical through the skin
and its distribution to one or more target organs where it may exert a toxic action
(Fig. 1). The anatomical site of contact is directly related to the activity being
performed at the time of exposure. Depending on the media and anatomical site
where contact occurs, the same contaminants can be absorbed very differently.
Several factors can influence the extent of dermal exposure. These include:
