Figure 4.

Micro-XRF element maps for As and Se and an overlay of As + Se for a dermal region of a mouse exposed to As(III) for 14 days and showing uptake of As into hair follicles. Colors are arbitrarily assigned and intensity is scaled to maximum observed area concentrations of As = 0.011 μg/cm² and Se = 0.010 μg/cm². The swirls and ovoid patterns are typical of follicle fields cut in cross section. These images show that As concentrated in the follicular epithelium is approximately the same as in the epidermal basal layer and that Se is relatively uniformly distributed throughout the dermis.