The podcast is about the work of Fiona MacNeill, a toxicologist at McMaster in Canada. She’s actually well known for her work on lead poisoning and if you google her you’ll turn up a number of scholarly articles and a couple of videos about her work.
Basically there were two forms of white lead make up in use between the sixteenth centuries – Ceruse and Venetian Ceruse.
By looking at early apothecary’s recipe books they were able to recreate the two forms of the cosmetic.
Ceruse is basically white lead ground up in pig fat or some other greasy vehicle make a paste which was then applied to the skin. While white lead is undoubtedly highly toxic, the skin forms an effective barrier against it, meaning that if the paste was only applied to unbroken skin, and no one licked either the area the paste was applied to, or the brush used for application, occasional use probably wouldn’t cause you serious harm.
Venetian ceruse was made differently and was essentially a mixture of vinegar, water and white lead, meaning that it was slightly acidic, and being acidic, removed the natural oils in the skin and allowed the white lead to penetrate into the subcutaeneous layer, which is most definitely not a good thing.
They found this out by painting samples on pig skin (pig skin is a good analogue for human skin) and studying the amount of penetration into the skin.
It is said that Elizabeth I of England used Ceruse, in part to hide skin blemishes caused by smallpox.
Actors playing Elizabeth often use a fairly grotesque white make up containing Titanium Dioxide. While there are concerns about titanium dioxide in cosmetics, it is certainly less toxic than white lead.
However, when Fiona MacNeill compared ceruse with a titanium dioxide based stage makeup, the ceruse came out with a warmer and more natural hue, meaning that Elizabeth did not look like a painted grotesque, but rather more like the historian Lucy Worsley dressed as Elizabeth I in this image from the BBC:
Which rather changes our image of Elizabeth, perhaps a little more natural looking.
However, Elizabeth is also reputed to have used arsenic based cosmetics to get rid of blemishes, perhaps caused by smallpox, perhaps caused by her used of Ceruse, which probably would not have improved her overall health …