An occupational hygiene assessment of dermal inorganic lead exposures in primary and intermediate user industries

Inorganic lead compounds are not normally considered to be a significant risk by skin exposure, the main routes of concern being inhalation of airborne dust and inadvertent ingestion, for example by hand-to-mouth contact. There is a lack of dermal exposure data for industrial workers and this information was required for a regulatory risk assessment purposes. The main aim of this study was to establish typical dermal lead exposures for lead production workers. A secondary aim was to investigate the potential for take-home contamination on the skin or hair, and make a limited evaluation of the potential for ingestion exposure due to hand-to-mouth contact or from deposition of contamination to the perioral region. Workplace surveys were carried out in a lead refinery and in a company producing litharge and other lead-containing powders, and a range of production tasks were studied. Dermal exposure samples were collected using a removal method, using commercial moist wipes to recover the lead deposits from measured areas of skin. The test procedures were validated before the workplace surveys and the average recovery efficiency for the sample preparation and analysis procedure was close to 100%. There were 32 complete sets of exposure measurements, from 32 different workers. Over 440 individual dermal exposure samples were collected for lead analysis. In addition, 14 sets of sample results from a zinc/lead refinery not previously reported, were reviewed and incorporated into this report. Dermal lead levels on the hands of those workers involved in molten metal areas or in ancillary operations were generally <10 μg/cm2. For the dustier tasks, average dermal lead exposures for the hands were generally within the range 10 - 200 μg/cm2. The observed pattern of exposure would be expected given the relatively mobile nature of the lead powder products and lead-concentrate dusts. It is concluded that overall, the dermal exposures were low and that this is largely due to the engineering controls applied to the production processes generally, combined with specific hygiene measures such as the consistent use of personal protective equipment. ""