Research Highlights

Dr. Alesia Ferguson's Ongoing Lab Project

Project Title: Experimentally Measuring Chemical Adhesion to the Human Skin
We are experimentally measuring surface residue transfer coefficients (i.e., percent transfer on contact) necessary for understanding and quantifying dermal exposure to toxic compounds (e.g., pesticides) in the home and at work. This project will use a mechanical device (Figure 1) to effectively facilitate the contact between cadaver skin (Figure 2) and common residential surfaces, laced with pesticides (e.g., Diazinon and Chlorpyrifos), to measure percent transfer for those pesticides as a function of contact pressure, time, temperature, humidity, and co-solvents. In the past, these coefficients have been estimated using hand presses and wipes, where the environmental conditions have not been controlled and the results can not be replicated. We hypothesize that chemical adhesion to human skin is highly variable and dependant on changes in the environment, the skin, and chemical properties. However, in order to more accurately estimate human exposure and dose, it is imperative that we understand and better estimate these coefficients more precisely. Reverse Phase High Performance Liquid Chromatography (RPHPLC) coupled with an Ultra Violet detector is currently being used to construct standards curves to aid in the identification of unknown masses of our pesticides after the residue transfer experiments. The success of our project depends on the effective design of the mechanical chamber. Dr. Wayne Johnson, Assistant Mechanical Engineering Professor at Armstrong Atlantic State University , has been hired to build the apparatus that will allow us to apply a desired contact pressure, temperature, and humidity while contacting human stratum corneum to surfaces that have been exposed to a particular pesticide concentration.

Figure 1: Sketch of Mechanical Chamber

Figure 2: Skin harvested from cadavers for use in experiments