• The International Agency for Research on Cancer, the NTP, and EPA have identified lead as likely to be carcinogenic to humans largely on the basis of nonhuman experimental evidence. The committee found no reason to disagree with those conclusions but notes that the available human studies were insufficient to support a conclusion about an association of BLLs with cancer in humans.
Given the committee’s findings about the inadequacy of the OSHA lead standard, DOD should review its guidelines and practices for protecting workers from lead exposure on firing ranges. One consideration should be a lowering of acceptable BLLs to more stringent levels that reduce the risk of adverse health effects. Professional organizations have called for more protective guidelines. For example, the American College of Occupational and Environmental Medicine has recommended medical removal of workers who have BLLs over 20 μg/dL, and the Council of State and Territorial Epidemiologists has suggested that the case definition of an elevated BLL in adults be changed from 25 μg/dL to 10 μg/dL. The Association of Occupational and Environmental Clinics has recommended more stringent guidelines for medical management of lead-exposed workers, which have been incorporated into DOD’s guidance for occupational medical examinations and surveillance. All those organizations recommend that BLLs be kept under 5 μg/dL in pregnant women to reduce the risk of spontaneous abortion. The Centers for Disease Control and Prevention has developed guidelines that recommend followup activities and interventions beginning at a BLL of 5 μg/dL in pregnant women.
Because little BLL data on DOD range workers were available, it was not possible to determine potential health risks to this specific population. However, data on airborne concentrations of lead on DOD firing ranges indicate that the current OSHA PEL is exceeded in the performance of some job duties, in some cases by several orders of magnitude, and this may lead to increased BLLs. Thus, DOD should consider analyzing BLLs of a representative sample of range workers in all the services and comparing them with BLLs linked to adverse health outcomes to understand potential health risks and to guide risk-management decisions at its ranges. Protecting workers from exposure to lead involves an integrated approach that combines protective air and BLL guidelines, environmental and biologic monitoring to ensure that the guidelines are met, environmental controls to minimize exposure to lead, and appropriately designed medical surveillance. Consideration should be given to performing risk analyses of available control options to determine the best way to minimize exposure to lead. Such analyses could include assessment of exposure to lead (and other contaminants) at ranges where lead-free or jacketed ammunition is primarily used, assessment of risks related to range design and ventilation controls, and evaluation of the contribution of surface contamination to oral lead exposure.