ABSTRACT
Aquatic pollutants may be absorbed into the skin by swimmers and bathers,
leading to the risk of exposure via the dermal route to a wide array of potentially
toxic pollutants. Many noxious pollutants [e.g., polyaromatic hydrocarbons (PAHs),
polychlorinated biphenyls, dioxins] are very lipophilic and are expected to partition
extensively into the stratum corneum lipids of human skin (1). In the past, concerns
about exposure to these fat-soluble water contaminants have been ignored since it
was thought that their low water solubility [e.g., water solubility of dichlorodiphe-
nyltrichloroethane (DDT) is 1.2 ppb] limited their maximum concentration to only
trace levels in water. However, lipophilic compounds are known to readily adsorb
to organic matter suspended in or floating on lake water. All natural aquatic bodies
have a thin film of floating oil (the surface slick, usually a mixture of natural oils
exuded from aquatic biota, decomposition products of biota, and natural seepage
of petroleum hydrocarbons) and lipophilic pollutants will partition into this phase
and reach concentrations far surpassing those in the subsurface water. Marine and
fresh water spills of crude oil from shipping as well as the effluent from power
engines used in boating and pleasure craft add to this oil slick. When bathers
immerse themselves in the water, their entire body surface would at once receive
total body coverage by this oil film along with its adherent floating sediment.
A bather is thus rapidly exposed over the entire skin surface to lipophilic
environmental contaminants dissolved and/or suspended in the slick. The rate
of transdermal absorption of these compounds is affected by the anatomic site
exposed, the chemical nature of the compound, environmental factors
(water temperature, pH, etc.), the use of commercial sun tan oils and other
“cosmetics,” and by the presence of dermal abrasions and other skin ailments (1,2).
