Using synchrotron techniques to better understand the dangers of historical white lead cosmetics
Conferences
Overview
Overview
abstract
Women (and men!) have been using lead-based cosmetics for millennia. Pliny the Elder discussed white lead face powder, noting it was poisonous, and it is believed that Queen Elizabeth the 1st used a cosmetic that was a mixture of white lead and vinegar. More recently, in the 19th century, the poisoning of young women from a cosmetic called Laird’s Bloom of Youth was well documented.
While the Laird’s Bloom of Youth poisonings provided some scientific data, in that they chemically analysed the makeup and performed urinalysis on the patients, the exact mechanisms of the poisonings are not well understood. White lead has usually been considered to be minimally absorbed through skin, but my laboratory has been studying whether lead from these cosmetics could be absorbed percutaneously, resulting in greater toxicity.
In this presentation, I plan to show you our μXRF maps of lead in skin, measured using the BioXAS beam line at the CLS, which demonstrate that lead from Laird’s Bloom of Youth could penetrate the skin. I will also show you μXRF maps that demonstrate that if Queen Elizabeth the 1st was using a white lead and vinegar mixture, she was likely poisoning herself through skin absorption of lead.
While our work on makeup is interesting in of itself, it is also transforming the more general understanding of the absorption of lead (Pb) into and through skin. I will share μXRF maps of lead acetate in skin which have revealed a measurement artifact that arises when a standard in vitro absorption testing methodology is used. This discovery suggests that percutaneous absorption of inorganic lead may be orders of magnitude greater than we have previously believed. I will also share some remarkable μXRF maps which have revealed that that lead binds to specific cells in skin, is taken up in sweat glands, and is transported through connective tissue, suggesting alternative transport routes of lead through the body.
I will finish by explaining our future plans and how XAS measurements should help us understand the interactions that can alter the chemical form of lead, changing absorption and creating the measurement artifact. I will also discuss how measurements on the MID-IR beamline may help us understand how changes in lipids and proteins by ingredients in makeup could permit diffusion of lead into skin.
