After looking at the really beautiful web site of “Invisible Zinc” Tim mentioned, I turned with interest to the “Sun Science” page. This contains links to three papers, presumably carefully chosen to educate the public on the science involved.
I was a little disappointed to note that, on this current “hot topic” of zinc oxide nanoparticle sun screens, two of the papers were published in 1997 and the third in 2002 – surely they could have found something a little more recent! Maybe the papers after this time note the fact that the results on possible skin penetration of the nanoparticles have been somewhat conflicting.
I also note that “Sun Science” makes no reference to the science of nanoparticles generating free radicals and any subsequent effects on the skin.