title: Dermal absorption and tissue disposition of 3,3',4, 4'-tetrachlorobiphenyl (TCB) in an ex-vivo pig model: assessing the impact of dermal exposure variables.
abstract: TCB is one of the dioxin-like polychlorinated biphenyls (PCBs). This research was designed to help assess the risk of occupational and environmental TCB exposure. To evaluate exposure variables' effects on dermal absorption and cutaneous disposition, 14C-TCB (40 microg/cm(2)) in acetone, methylene chloride, a water-acetone mixture, and a soil-based mixture were applied in an ex-vivo pig-skin-flap model (n = 4-5/treatment). Dermal absorption (0.11-0.66%, 8 hr) and penetration (1.14-2.48%) varied according to exposure conditions. Acetone and methylene chloride vehicles differed in absorption profiles and skin penetration patterns but were similar in absorption amounts. Adding water to the acetone did not change absorption but did alter the penetration pattern. The non-occluded soil-based mixture showed more absorption than did the liquid vehicles (p<0.05), but occlusion significantly (p<0.05) decreased that absorption (0.66-->0.29%, 8 hr) and penetration (2.48-->1.11%). In conclusion, dermal absorption data from liquid-organic or aqueousorganic mixtures may underestimate the risk of exposure to TCB-contaminated soil.
authors.affiliation: NIOSH, Centers for Disease Control, Morgantown, WV 26505-2888, USA. gaq1@cdc.gov
authors.forename: G
authors.initials: G
authors.lastname: Qiao
authors.forename: J E
authors.initials: JE
authors.lastname: Riviere
mesh_terms: D000818:Animals; D005260:Female; D016014:Linear Models; D014677:Pharmaceutical Vehicles; D010599:Pharmacokinetics; D011078:Polychlorinated Biphenyls / Q000378:metabolism*; D012867:Skin / Q000187:drug effects*; D012869:Skin Absorption; D012989:Soil Pollutants / Q000378:metabolism; D013552:Swine
chemical_list: D014677:Pharmaceutical Vehicles; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls