I have been at NAVFACs before the vacuum system and after the vacuum systems were fitted. I worked maintenance and was not on the operation floor for long hours. I am not certain as to the health issues, but the carbon dust was a potential for short-circuits and creating crossing to the different grounds (signal to power grounds).

The Precipitron Air Filtering System was installed to keep the air clean to the Honeywell tape recorders. We saved many man-hours of labor by connecting the Precipitron Air Filtering System input directly into the air conditioning duct.