Percutaneous absorption of uranium compounds.

Percutaneous absorption of soluble and insoluble uranium compounds has been induced in order to obtain information on penetration routes and the tissue injury produced by uranium salts. The high electron density of uranium provided a reliable way to visualize, by electron microscopy, the precise localization of the heavy compounds within the tissues. Few minutes after topical application of uranyl nitrate, dense deposits of uranium were observed at the epidermal barrier level. A few hours later, dense deposits were seen filling the intercellular spaces and were also scattered in the cytoplasm and nucleus. Mortality and body weight measurements indicated the high toxicity of uranyl nitrate and ammonium uranyl tricarbonate; uranyl acetate and ammonium diuranate were less toxic. As no penetration was achieved after uranium dioxide, no variations were detected on these parameters.