Skin absorption of inorganic lead (PbO) and the effect of skin cleansers

OBJECTIVE: The aim of this study was to investigate the percutaneous penetration of lead oxide (PbO) powder and the effect of rapid skin decontamination with two different detergents. METHODS: Franz cells were used to study in vitro PbO skin penetration through human skin during a 24-hour period. The tests were performed without or with decontamination using either Ivory Liquid soap or a new experimental cleanser 30 minutes after the start of exposure. RESULTS: We confirm that PbO can pass through the skin with a median penetration of 2.9 ng/cm (25-75th percentiles 0.35-6). The cleaning procedure using Ivory Liquid soap significantly increased skin penetration with a median value of 23.6 ng/cm (25-75th percentiles 12-47.1; Mann-Whitney U test, P = 0.0002), whereas the new experimental cleanser only marginally increased penetration (7.1 ng/cm). CONCLUSIONS: Our results indicate that it is necessary to prevent skin contamination from occurring because a short contact can increase skin content and penetration even if quickly followed by washing. This study demonstrated that PbO powder can pass through the skin and that skin decontamination done after 30 minutes of exposure did not decrease skin absorption occurring over 24 hours and stresses the need to prevent skin contamination when using toxic substances.