IDENTIFYING METALLIC DUST PARTICLES SUSPENDED IN THE BREATHING ZONE OF VARIOUS UNIVERSITY ROOMS USING X-RAY FLUORESCENCE SPECTROSCOPY (XRF)

Metallic dust particles suspended in the breathing zone were identified in a classroom, conference room, working laboratory, newly constructed laboratory, and a machine shop in Moser Hall at Youngstown State University. Vacuum pumps sucked 20 liters of air per minute for 24 hours through cassettes where dust was trapped onto filter papers. Particulates were analyzed using an x-ray fluorescence spectrometer (XRF, yellow filter, 40 kV and 10 µa). The spectrogram peaks allowed identification of the metals and indicated relative amounts in counts per second using XRF manufacturer-provided software. A blank filter paper was analyzed for background.

Results for the classroom, the conference room, and the working laboratory (fume-hood exhaust fans running) were identical to the blank filter, indicating no elevated levels of metallic particulates in those areas. It was expected that the machine shop used to fabricate metal parts for laboratory apparatus would show elevated levels of metallic particulates; these levels were observed, especially with a high peak of iron. Not initially anticipated were elevated levels of metals in the newly constructed laboratory. The construction activities, however, included sawing gypsum wallboard (calcium), cutting and connecting wiring (copper and zinc), and drilling through reinforced concrete floors and walls (iron, and other metals). As these fume-hood exhaust fans were not being used, particulates from the construction were not yet vacuumed from the air in this new facility.

Metallic elements present included iron, manganese, zinc, calcium, nickel, copper, lead, and cadmium. All dust particles in ambient air present health concerns, especially those that are less than 2.5 microns in diameter and have the possibility of being lodged into lung tissue or passing into the bloodstream.