I enjoyed you article on skin. The question I have is this: is the porosity of the skin, or maybe more correctly, is the permativity of the skin uniform across the body. I suspect that it isn’t (I’ve had contact dermatitis from poison ivy all over my body, but never on the front of my hands, and that goes for everyone else I know) but would love to see some additional data supoorting this. Do you know of any?
My main concern is with the reports that people are taking up bisphenol A from register receipts. Since these receipts are only handled with the figer tips, I suspect that the amount absorbed is minimal.
I am not an expert on skin by any means, but I can offer the following observations in answer to the question.
The thickness of the skin varies from place to place around the body and I presume, as a consequence, the susceptibility to react to substances also varies to a certain extent, but this will depend upon the type of substance, and the effect it has on the skin. There are unlikely to be studies that will give more detailed information; a textbook on skin biology is probably a more likely source.
With regard to BPA, again, I am not an expert, but I find it difficult to accept that the vanishingly small quantities that may be transferred onto skin from till receipts would contribute any risk to human health. This is only my opinion.