Manganese Exposures for Navy Workers. This information was taken from a study conducted by the Navy Environmental Health Center. It suggests that Navy personnel may be at risk for exposure to manganese. Conclusions presented in this study should be considered by DA Health authorities to determine if similar exposure potentials exist for Army personnel. In June 1996, the Deputy Under Secretary of Defense (Environmental Security) requested an evaluation of manganese exposures to Navy workers, and an assessment of the impact of a reduced manganese standard. Background note - The American Conference of Governmental Industrial Hygienists (ACGIH) Chemical Substances TLVr Committee has determined that manganese is a chronic toxin and that a time weighted average (TWA) exposure limit over the work day is appropriate. In 1992, the TLV Committee proposed a Notice of Intended Change for manganese as a TLV-TWA of 200 ug/m3 as manganese for elemental and inorganic compounds. The previous TLVs were similar to the OSHA PELs, which were vacated by the Eleventh Circuit Court of Appeals in July 1992. These values were 5,000 ug/m3 as a ceiling limit for dust, 3,000 ug/m3 as a short-term exposure limit (STEL), with a 1,000 ug/m3 limit as an 8hour TWA for fumes. In setting the PELs OSHA had concluded that both a TWA and a STEL limit were required to protect workers from manganese fume poisoning, lung damage and pneumonia. Because the PELs were vacated, the current OSHA PEL reinstates the old value of 5,000 ug/m3 as a ceiling limit for both dust and fume. Manganese may be absorbed both from the lungs and GI tract. Inhalation exposure to high levels of manganese can lead to a disabling neurological syndrome "manganism". The Chief of Naval Operations (N45 staff) convened a Navy working group comprised of technical professionals representing the Bureau of Medicine and Surgery, Marine Corps, Naval Sea Systems Command, Naval Air Systems Command, Navy Environmental Health Center, and Naval Surface Warfare Center Carderock Division. This group analyzed the tasking and developed an action plan to prepare this report. The primary author and coordinator for the report was Mr. John Bishop, Navy Environmental Health Center. The study concluded the following: *666 exposures were reviewed *95 % of the TWA exposures (with 95 % confidence) of the population performing the operation were below the anticipated OSHA PEL of 200 ug/m3 *7% of the exposures were at or above the anticipated action level of 100 ug/m3, and *3.5% of the exposures were at or above the anticipated PEL of 200 ug/m3. *Work operations with assessments greater than 100 ug/m3 are mechanical metal cleaning (e.g., abrasive blasting), welding, thermal cutting, and utilities (e.g., boiler maintenance). *There were two mechanical cleaning assessments that resulted in concentrations >1000 ug/m3. The report also summarized types of engineering control that is being used to reduce manganese exposures to workers. SOURCE: http://list. uvm.edu/cgi- bin/wa?A2= ind9704D. ..FETY&P=4758 Jerrel svr _________________ Elk Hunt Test #65_14_Gerstle River Test Site_Landbase Test_Ft. Greely AK. 1964_S.R.#99_06 “We'll know our disinformation program is complete when everything the American public believes is false.”-- William Casey, CIA Director!!!