Dermal Exposure to Beryllium: A Pilot Case Study

Abstract

The issue of dermal absorption of beryllium (Be) particles through intact healthy skin has not yet been demonstrated. The interest in Be dermal exposure as a potential pathway for toxic effects was emphasized in Quebec (Canada) when a recycling industry processing spent pot lining (SPL) related to the aluminum industry was recently requested by health authorities to conduct a Be particle size study and to provide a Tyvek coverall for full skin protection of workers. This study aimed to (1) calculate the dermal and inhalation exposures and (2) apply the results to the case study of a recycling SPL industry. Airborne dust was sampled in order to determine Be particles size. Exposure assessment via the skin and the respiratory routes was measured over a working day using standard calculations. The assessment of workers’ clothing protection was obtained by swiping the skin on the forearm and upper front leg before and after exposure. Respirable Be (0.044 μg) was 23% of the total Be (0.19 μg). Be particles with a median mass aerodynamic diameter (MMAD) of 0.93 and below totaled 0.0103 μg (5% of BeT). The daily dose for the respiratory route was calculated to be 0.022 μg/kg/d, while the daily doses for the dermal route varied between 0.027 × 10−7 μg/kg/d and 0.025 × 10−3 μg/kg/d. After exposure, no Be was found on the skin of workers wearing a cotton coverall protection. When using a polyester coverall, minor amounts of Be were found. These results showed that dermal daily dose exposure is negligible. However, note that the case study did not involve handling of contaminated items by the workers, which lead to significant dermal exposure if care is not taken. Although daily dermal exposure may be small, because of uncertainties, a precautionary principle should be applied in an active sense.