Abou-Elwafa Abdallah Mohamed, Pawar Gopal, Harrad Stuart
Division of Environmental Health and Risk Management, School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom; Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt.
Division of Environmental Health and Risk Management, School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom.
Toxicol Appl Pharmacol. 2016 Jan 15;291:28-37. doi: 10.1016/j.taap.2015.12.004. Epub 2015 Dec 19.
Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP) are organophosphate flame retardants (PFRs) widely applied in a plethora of consumer products despite their carcinogenic potential. Human dermal absorption of these PFRs is investigated for the first time using human ex vivo skin and EPISKIN™ models. Results of human ex vivo skin experiments revealed 28%, 25% and 13% absorption of the applied dose (500 ng/cm(2), finite dose) of TCEP, TCIPP and TDCIPP, respectively after 24h exposure. The EPISKIN™ model showed enhanced permeability values (i.e. weaker barrier), that were respectively 16%, 11% and 9% for TCEP, TCIPP and TDCIPP compared to human ex vivo skin. However, this difference was not significant (P>0.05). Estimated permeability constants (Kp, cm/h) showed a significant negative correlation with log Kow for the studied contaminants. The effect of hand-washing on dermal absorption of PFRs was investigated. Washing reduced overall dermal absorption, albeit to varying degrees depending on the physicochemical properties of the target PFRs. Moreover, slight variations of the absorbed dose were observed upon changing the dosing solution from acetone to 20% Tween 80 in water, indicating the potential influence of the dose vehicle on the dermal absorption of PFRs. Finally, estimated dermal uptake of the studied PFRs via contact with indoor dust was higher in UK toddlers (median ΣPFRs=36 ng/kg bw day) than adults (median ΣPFRs=4 ng/kg bw day). More research is required to fully elucidate the toxicological implications of such exposure.
磷酸三（2-氯乙基）酯（TCEP）、磷酸三（1-氯-2-丙基）酯（TCIPP）和磷酸三（1,3-二氯丙基）酯（TDCIPP）是有机磷酸酯阻燃剂（PFRs），尽管它们具有致癌潜力，但仍广泛应用于众多消费品中。首次使用人体离体皮肤和EPISKIN™模型研究了人体对这些PFRs的皮肤吸收情况。人体离体皮肤实验结果显示，暴露24小时后，TCEP、TCIPP和TDCIPP的施用剂量（500 ng/cm²，有限剂量）的吸收量分别为28%、25%和13%。EPISKIN™模型显示出通透性增强的值（即屏障较弱），与人体离体皮肤相比，TCEP、TCIPP和TDCIPP的通透性分别为16%、11%和9%。然而，这种差异并不显著（P>0.05）。估计的通透常数（Kp，cm/h）与所研究污染物的log Kow呈显著负相关。研究了洗手对PFRs皮肤吸收的影响。洗手减少了总的皮肤吸收，尽管程度因目标PFRs的物理化学性质而异。此外，当将给药溶液从丙酮改为水中20%的吐温80时，观察到吸收剂量有轻微变化，表明给药载体对PFRs皮肤吸收的潜在影响。最后，英国幼儿通过接触室内灰尘对所研究的PFRs的估计皮肤摄入量（ΣPFRs中位数=36 ng/kg bw/天）高于成年人（ΣPFRs中位数=4 ng/kg bw/天）。需要更多研究来充分阐明这种暴露的毒理学影响。
