Assessing dermal exposure to metal dusts : monitoring, modelling and understanding its relevance to local and systemic effects

Rigorous evaluation of high production volume chemicals are required (ECB, 20031, but there are few occupational dermal exposure data to aid the risk assessments. Dermal exposure assessment methodology is also in the early stages of development (Fenske, 2000). The physical properties of metals need to be take into account when measuring exposure and assessing risks (Flint, 1998). A method was therefore developed to measure dermal exposure to metal particles, and workplace surveys were carried out for antimony, lead, zinc and nickel. Inhalation exposure data were also collected for comparison with the dermal exposure measurements. The dermal exposures for nickel workers were used to assess the risk of induction or elicitation of nickel sensitivity. A mathematical model was constructed to describe the total systemic absorption from inhalation, dermal and ingestion routes of exposure for all four of the substances. The summary data for each of the exposure categories were used as inputs to the model and estimates of absorbed dose were derived. The soluble nickel exposures for nickel production workers were in some cases well in excess of the NOEL value of 0.3 ug/crn" (DEPA, 2008) for elicitation of nickel dermatitis in nickel sensitive individuals, indicating that individuals with pre-existing nickel sensitivity should not be employed in this industry. Only the stainless steel production worker exposures were below the NOEL value. The absorption model showed that absorption by the dermal route could equal that of the inhaled dose for antimony workers. The dermal absorption of lead for lead workers was found to be insignificant compared to inhalation exposures. In the zinc industry, the estimated dermal absorption was significant in the zinc chemical production processes, but not in zinc refining or in galvanising. In the case of nickel industry, the dermal absorption was significant for electro winning, nickel compounds and nickel powder production.EThOS - Electronic Theses Online ServiceGBUnited Kingdo