Wang Meichen, Phillips Timothy D
Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843, United States.
ACS Appl Mater Interfaces. 2022 May 10. doi: 10.1021/acsami.2c04676.
Dermal exposures to environmental chemicals can significantly affect the morphology and integrity of skin structure, leading to enhanced and deeper penetration of toxic chemicals. This problem can be magnified during disasters where hazardous water-soluble chemicals are readily mobilized and redistributed in the environment, threatening the health of vulnerable populations at the impacted sites. To address this issue, barrier emulsion formulations (EVB) have been developed consisting of materials that are generally recognized as safe, with the inclusion of medical grade carbon or calcium and sodium montmorillonite clays (CM and SM). In this study, the adsorption efficacy of five highly toxic and commonly occurring contaminants of concern, including important hydrophilic pesticides (glyphosate, acrolein, and paraquat) and per- and polyfluoroalkyl substances were characterized. EVB showed properties such as high stability, spreadability, low rupture strength, and neutral pH that were suitable for topical application on the skin. The in vitro adsorption results indicated that EVB and EVB-SM were effective, economically feasible, and favorable barrier formulations for hazardous chemical adsorption, as supported by high binding percentage, low desorption rates for an extended period of time, and high binding affinity. A pseudo-second-order kinetic model was best fitted for the adsorption process and the Freundlich model fit the adsorption isotherms with negative enthalpy values indicating spontaneous reactions that involve physisorption. The study, with varying temperatures and pH, showed that the adsorption reaction was exothermic and persistent. The results indicated that EVB and EVB-SM can be used as effective barriers to block dermal contact from water-soluble toxic pollutants during disasters.
皮肤接触环境化学物质会显著影响皮肤结构的形态和完整性，导致有毒化学物质的渗透增强且更深。在灾害期间，这个问题会被放大，因为有害的水溶性化学物质很容易在环境中移动和重新分布，威胁到受灾地区弱势群体的健康。为了解决这个问题，已经开发出了屏障乳液配方（EVB），其由一般被认为是安全的材料组成，包括医用级碳或钙蒙脱石和钠蒙脱石粘土（CM和SM）。在这项研究中，对五种高毒性且常见的关注污染物的吸附效果进行了表征，这些污染物包括重要的亲水性农药（草甘膦、丙烯醛和百草枯）以及全氟和多氟烷基物质。EVB具有高稳定性、铺展性、低破裂强度和中性pH等特性，适合局部应用于皮肤。体外吸附结果表明，EVB和EVB-SM是用于有害化学物质吸附的有效、经济可行且良好的屏障配方，这得到了高结合百分比、长时间低解吸率和高结合亲和力的支持。吸附过程最适合用准二级动力学模型，Freundlich模型适合吸附等温线，负焓值表明涉及物理吸附的自发反应。该研究在不同温度和pH下进行，结果表明吸附反应是放热且持久的。结果表明，EVB和EVB-SM可作为有效的屏障，在灾害期间阻断皮肤与水溶性有毒污染物的接触。
