Complex mixture effects on the dermal absorption of benzo[a]pyrene and other polycyclic aromatic hydrocarbons from mouse skin

Abstract

To study the dermal penetration of benzo[a]pyrene (BAP) in relation to other polycyclic aromatic hydrocarbons (PAHs), a complex mixture of PAHs was applied to the backs of CD-1 mice, and the dermal residence times of BAP and eleven other PAHs were determined using gas chromatography. The dermal penetration of BAP was found to be representative of the other PAHs studied, with a dermal half-life of 6.7 h. Half-lives of the other eleven PAHs ranged from 5.0 to 8.8 h. The dermal half-life of BAP applied in a volatile organic solvent, rather than a PAH mixture, was 3.0 h. The effects of five complex organic mixtures, with boiling points ranging from 300-700 degrees F to greater than 850 degrees F, on the dermal residence time of BAP was studied by adding radiolabeled BAP to the mixtures, and applying them to the backs of mice. All of the mixtures studied increased the dermal residence time of BAP by amounts ranging from 1.8-fold to 6.9-fold.

Atsdr Evaluation of Health Effects of Chemicals. Iv. Polycyclic Aromatic Hydrocarbons (PAHs): Understanding a Complex Problem

“…For example, environmental contaminants such as tetrachlorodibenzo-p-dioxin (TCDD), polychlorinated biphenyls (PCBs) and 3,3',4, can increase microsomal enzyme activity and consequently affect PAH toxicity (Jacob et al, 1987;Kouri et al, 1978). The dermal absorption of benzo[a]pyrene was measured in the presence or absence of complex organic mixtures derived from coal liquefaction processes (Dankovic et al, 1989). The dermal half-life of benzo[a]pyrene was 3.0 hours when applied alone, 6.7 hours when measured as a component of a mixture, and ranged from 7.8 to 29.7 hours in the presence of different mixtures.…”

The Gulf Oil Spill

“…For example, environmental contaminants such as tetrachlorodibenzo-p-dioxin (TCDD), polychlorinated biphenyls (PCBs) and 3,3',4,4'-tetrachlorobiphenyl (TCBP) can increase microsomal enzyme activity and consequently affect PAH toxicity (Jacob et al 1987;Kouri et al 1978). The dermal absorption of benzo[a]pyrene was measured in the presence or absence of complex organic mixtures derived from coal liquefaction processes (Dankovic et al 1989 Concomitant exposure to solvents may also occur, particularly in an occupational setting. It has been demonstrated that pretreatment of rats with toluene (1 g/kg intraperitoneally) inhibits the total cytochrome P-450 content in microsomes isolated from the lungs (Furman et al 1991 Asbestos exerts a synergistic influence on cigarette smoke (which contains several PAHs) in the development of bronchopulmonary cancers.…”

Quantitating the Percutaneous Absorption of Mechanistically-Defined Chemical Mixtures

“…Possible interactions include chemical binding, chemical effects from surfactants, stratum corneum lipid interactions from enhancers, solventmediated lipid extraction, low level irritation, and vasomodulation. Dankovic (1989) had reported on prolonged dermal residence times for benzo [a]pyrene when applied in a mixture of 11 polycyclic aromatic hydrocarbons compared to application in a volatile solvent. All of this previous work suggests that such subtle changes in absorption from mixtures is not unexpected.…”