Although the federal Occupational Safety and Health Administration (OSHA) has yet to undertake revisions to its nearly 40-year old permissible exposure level (PEL) for lead, several states (e.g., California, Washington, and Oregon) are actively considering revised workplace standards. In a paper recently published in the Journal of Occupational and Environmental Hygiene, Gradient scientists examined the roles of particle size and other factors in setting occupational exposure limits (OELs) for lead. The data Gradient analyzed – airborne lead particle size distributions from US battery manufacturing and secondary lead smelter facilities – were collected more recently than much of the data previously available in the published scientific literature or used in setting the existing standards and thus provide a more updated reflection of US workplace conditions in these industries. Gradient modeled particle deposition in the respiratory tract, explored how different deposition patterns could influence estimated lead absorption, and assessed implications for setting lead OELs. This paper highlights the importance of ensuring that lead exposure data and approaches applied by states and others in setting OELs are integrated in ways that are consistent and scientifically sound, and adequately consider the degree to which historical data are applicable for current workplace conditions.
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