Dermal exposure to environmental contaminants in the Great Lakes.

Abstract

This paper reviews the literature to determine the importance of the dermal route of exposure for swimmers and bathers using Great Lakes waters and summarizes the chemical water contaminants of concern in the Great Lakes along with relevant dermal absorption data. We detail in vivo and in vitro methods of quantifying the degree of dermal absorption and discuss a preference for infinite dose data as opposed to finite dose data. The basic mechanisms of the dermal absorption process, routes of chemical entry, and the environmental and physiological factors affecting this process are also reviewed, and we discuss the concepts of surface slick exposure to lipophilic compounds and the adsorption of contaminants to water sediment. After presenting mathematical constructs for calculating the degree of exposure, we present in vitro data concerning skin absorption of polyaromatic hydrocarbons adsorbed to Great Lakes water sediment to show that in a worst-case scenario exposure via the dermal route can be equally important to the oral route. We have concluded that prolonged exposure of the skin, especially under conditions that may enhance dermal absorption (e.g., sunburn) may result in toxicologically significant amounts of certain water contaminants being absorbed. It is recommended that swimming should be confined to public beaches, people should refrain from swimming if they are sunburned, and skin should be washed with soap as soon as possible following exposure. Future studies should be conducted to investigate the importance of the dermal exposure route to swimmers and bathers.

Health Implications of PAH Release from Coated Cast Iron Drinking Water Distribution Systems in the Netherlands

“…On the basis of a maximum phenanthrene concentration of 6 μg/L in drinking water (Table 2) and a surface body area of 18,000 cm 2 , we calculated that 30 min of daily bathing or showering would result in a dermally absorbed phenanthrene dose of only 86 ng/person/day, compared with our estimated 12,000 ng/person/day from daily oral ingestion of 2 L of drinking water. Data from other studies indicate that dermal absorption of other PAHs is not significantly higher than absorption of phenanthrene (Moody and Chu 1995; Sartorelli et al 1999; Van Rooij et al 1995). …”

“…We did not estimate dermal exposure during bathing or showering because a ) data on dermal absorption of PAHs from aqueous matrices are scarce, b ) absorption of PAHs is highly dependent on the vehicle used in the tests, and c ) available information suggests that exposure from dermal absorption would be negligible compared with oral ingestion from drinking water. Specifically, Moody and Chu (1995) examined dermal absorption of 14 C-labeled phenanthrene in vitro in human skin and observed 24% absorption after exposure of 0.64 cm 2 skin for 24 hr to a 0.1 mL solution of 1 µg/mL phenanthrene. From this, an equilibrium constant in terms of partial pressure ( K p ) was determined (1.6 × 10 –3 cm/hr) (Moody and Chu 1995).…”

“…Specifically, Moody and Chu (1995) examined dermal absorption of 14 C-labeled phenanthrene in vitro in human skin and observed 24% absorption after exposure of 0.64 cm 2 skin for 24 hr to a 0.1 mL solution of 1 µg/mL phenanthrene. From this, an equilibrium constant in terms of partial pressure ( K p ) was determined (1.6 × 10 –3 cm/hr) (Moody and Chu 1995). On the basis of a maximum phenanthrene concentration of 6 μg/L in drinking water (Table 2) and a surface body area of 18,000 cm 2 , we calculated that 30 min of daily bathing or showering would result in a dermally absorbed phenanthrene dose of only 86 ng/person/day, compared with our estimated 12,000 ng/person/day from daily oral ingestion of 2 L of drinking water.…”

Bioavailability of insect growth regulator residues in citrus

“…Previous studies have confirmed soil matrix is an important factor in determining a pesticides' bioavailability (Umbreit et al 1986(Umbreit et al , 1988. Some authors have reported pesticides' bioavailability rates in dermal absorption from water (Wester et al 1987;Moody and Chu 1995). Also, there are publications about lung absorption of pesticides in work atmosphere (Chester 1993).…”

Sunscreens containing physical UV blockers can increase transdermal absorption of pesticides

“…Exposure to ultraviolet (UV) radiation above a threshold level can cause damage to the barrier properties of the skin and has been shown to increase the dermal penetration of small hydrophilic chemicals (Gelis et al, 2002). This is a problem because dermal absorption is a major source of chemical exposure in occupational and agricultural (Fenske and Elkner, 1990;Nielsen and Nielsen, 2000;Nomiyama et al, 2001) as well as recreational settings (Lindstrom et al, 1997;Moody and Chu, 1995;Xu et al, 2002). Sunscreen use should, therefore, help prevent this damage and reduce the absorption of undesirable penetrants.…”