Review of the Department of Defense Biokinetic Modeling Approach in Support of Establishing an Airborne Lead Exposure Limit

Review of the Department of Defense Biokinetic Modeling Approach in Support of Establishing an Airborne Lead Exposure Limit
Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
Total Pages: 49
Release: 2020-04-30
Genre: Nature
ISBN: 0309671922

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Biokinetic modeling provides a mathematical technique for estimating absorption, distribution, metabolism, and excretion of chemicals, including particles and metals, in humans. Such models can be used to relate the amount of lead external exposure to the amount of lead found in the blood and other tissues at different points in time. At the request of the Department of Defense (DoD), Review of the Department of Defense Biokinetic Modeling Approach in Support of Establishing an Airborne Lead Exposure Limit evaluates whether the model used by DoD to derive airborne lead concentrations from blood lead levels is appropriate. This report also considers whether DoD's modifications to the model are appropriately justified, and whether the assumptions in and inputs to the model are reasonable.

Review of the Department of Defense Biokinetic Modeling Approach in Support of Establishing an Airborne Lead Exposure Limit

Review of the Department of Defense Biokinetic Modeling Approach in Support of Establishing an Airborne Lead Exposure Limit
Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
Total Pages: 49
Release: 2020-03-30
Genre: Nature
ISBN: 0309671957

Download Review of the Department of Defense Biokinetic Modeling Approach in Support of Establishing an Airborne Lead Exposure Limit Book in PDF, Epub and Kindle

Biokinetic modeling provides a mathematical technique for estimating absorption, distribution, metabolism, and excretion of chemicals, including particles and metals, in humans. Such models can be used to relate the amount of lead external exposure to the amount of lead found in the blood and other tissues at different points in time. At the request of the Department of Defense (DoD), Review of the Department of Defense Biokinetic Modeling Approach in Support of Establishing an Airborne Lead Exposure Limit evaluates whether the model used by DoD to derive airborne lead concentrations from blood lead levels is appropriate. This report also considers whether DoD's modifications to the model are appropriately justified, and whether the assumptions in and inputs to the model are reasonable.

Potential Health Risks to DOD Firing-Range Personnel from Recurrent Lead Exposure

Potential Health Risks to DOD Firing-Range Personnel from Recurrent Lead Exposure
Author: National Research Council
Publisher: National Academies Press
Total Pages: 199
Release: 2013-04-20
Genre: Medical
ISBN: 0309267366

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Lead is a ubiquitous metal in the environment, and its adverse effects on human health are well documented. Lead interacts at multiple cellular sites and can alter protein function in part through binding to amino acid sulfhydryl and carboxyl groups on a wide variety of structural and functional proteins. In addition, lead mimics calcium and other divalent cations, and it induces the increased production of cytotoxic reactive oxygen species. Adverse effects associated with lead exposure can be observed in multiple body systems, including the nervous, cardiovascular, renal, hematologic, immunologic, and reproductive systems. Lead exposure is also known to induce adverse developmental effects in utero and in the developing neonate. Lead poses an occupational health hazard, and the Occupational Safety and Health Administration (OSHA) developed a lead standard for general industry that regulates many workplace exposures to this metal. The standard was promulgated in 1978 and encompasses several approaches for reducing exposure to lead, including the establishment of a permissible exposure limit (PEL) of 50 μg/m3 in air (an 8-hour time-weighted average [TWA]), exposure guidelines for instituting medical surveillance, guidelines for removal from and return to work, and other risk-management strategies. An action level of 30 μg/m3 (an 8-hour TWA) for lead was established to trigger medical surveillance in employees exposed above that level for more than 30 days per year. Another provision is that any employee who has a blood lead level (BLL) of 60 μg/dL or higher or three consecutive BLLs averaging 50 μg/dL or higher must be removed from work involving lead exposure. An employee may resume work associated with lead exposure only after two BLLs are lower than 40 μg/dL. Thus, maintaining BLLs lower than 40 μg/dL was judged by OSHA to protect workers from adverse health effects. The OSHA standard also includes a recommendation that BLLs of workers who are planning a pregnancy be under 30μg/dL. In light of knowledge about the hazards posed by occupational lead exposure, the Department of Defense (DOD) asked the National Research Council to evaluate potential health risks from recurrent lead exposure of firing-range personnel. Specifically, DOD asked the National Research Council to determine whether current exposure standards for lead on DOD firing ranges protect its workers adequately.The committee also considered measures of cumulative lead dose. Potential Health Risks to DOD Firing-Range Personnel from Recurrent Lead Exposure will help to inform decisions about setting new air exposure limits for lead on firing ranges, about whether to implement limits for surface contamination, and about how to design lead-surveillance programs for range personnel appropriately.

Lead Exposures and Biological Responses in Military Weapons Systems

Lead Exposures and Biological Responses in Military Weapons Systems
Author:
Publisher:
Total Pages: 138
Release: 1993
Genre:
ISBN:

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This study was to determine the concentration and chemical nature of lead (Pb) aerosols produced during the firing of artillery and to determine the exposures and biological responses of crew members exposed to lead aerosols during such firing. The concentrations of lead-containing aerosols at crew positions depended on wind conditions, with higher concentrations when firing into a head wind. Aerosol concentrations were highest in the muzzle blast zone. Concentrations of lead in the blood of crew members rose during the first 12 days of exposure to elevated airborne lead concentrations and then leveled off. There was no rapid decrease in blood lead concentrations after completion of firing. Small decreases in hematocrit and small increases in free erythrocyte porphyrin were correlated with increasing exposure to airborne lead. These changes were reversed by seven weeks after firing. Changes in nerve conduction velocity had borderline statistical significance to airborne lead exposure. In measuring nerve conduction velocity, differences in skin temperature must be taken into account.

Biological Responses of 155mm Howitzer Crewmen to Airborne Lead

Biological Responses of 155mm Howitzer Crewmen to Airborne Lead
Author:
Publisher:
Total Pages: 175
Release: 1994
Genre:
ISBN:

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Lead health effects are largely unknown for short-duration, high-concentration exposures resulting from weapon firings. Cumulative air lead exposure proved to have a significant statistical relationship with the change in blood lead over the period of the study. Small, but statistically significant changes occurred in both hematocrit and Free Erythrocyte Protoporphyrin (PEP). All but four study subject exceeded mean 24-hr exposures for airborne lead (PbA) using the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) of 16.7 micrograms/cu m. Significant PbA exposures were reliably associated with the firing of high-zone M119 and M203 charges but not low-zone charges. Baseline blood lead concentrations (PbB) were quite low for all groups, despite evidence for recent prior exposures Blood lead increases did not exceed the OSHA Action Level of 40 micrograms/dL although twelve individuals had blood lead levels in excess of 30 micrograms/dL. Statistically significant correlations could be found between maximum (peak) blood lead levels and mean 8-hr time-weighed airborne average (TWA). Large NCV decreases of 8.0 and 11.6 m/sec were found in the ulnar sensory nerve for two of the M109A3 crewmen. Statistically significant NCV decreases were found for the peroneal motor nerve during the period following exposure.

Review of the Department of Defense Research Program on Low-Level Exposures to Chemical Warfare Agents

Review of the Department of Defense Research Program on Low-Level Exposures to Chemical Warfare Agents
Author: National Research Council
Publisher: National Academies Press
Total Pages: 122
Release: 2005-12-08
Genre: Science
ISBN: 0309181534

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Research related to chemical warfare agents (CWAs) has historically focused on life threatening battlefield effects caused by high level exposures to the agents, not effects associated with exposures to low concentrations of them. In this report, low level concentrations refers to exposures that may not have any immediate observed health effects, but may produce delayed health effects months or years later. Recently, there has been increased concern about the potential health effects of exposures to CWAs at low concentrations. This report reviews the Department of Defense's (DOD) Research Plan for obtaining toxicologic and other relevant data to assess risk to military personnel. The CWAs of concern include the following nerve and vesicant agents: tabun, sarin, soman, cyclosarin, VX, and sulfur mustard. The report discusses the health effects of exposure to low levels of these agents and provides guidance to DOD on appropriate risk assessment methods for assessing toxicologic risk to military personnel from low-level exposures to CWAs. The report concludes that DOD's Research Plan is well planned and many of the proposed research tasks are likely to provide valuable information to DOD in protecting military personnel.