The Exposure Assessment unit of this Facility Core focuses on field measurement through direct-reading instruments and field sampling. An extensive collection of equipment is available to Core members including -occupational hygiene, environmental sam-pling, and direct-reading field instruments, as well as calibration and research instru-ments. A full range of sampling pumps from battery-powered personal sampling pumps to high-volume samplers and flow calibration devices are also available. A small weighing room with a Cahn Electrobalance (sensitivity 0.1 µg) is available. A larger constant temperature and humidity weighing room is under construction as part of the PM Center aerosol instrumentation unit.

Several laboratories for calibration and validation are available for use by the Core. They include a 50-m2 (530 ft2) teaching laboratory for exposure assessment course work on sampling, measure-ment, and analysis of airborne contami-nants and for student research, an aerosol research labora-tory, and three toxicol-ogy laborato-ries including a 23-m2 (250 ft2) laboratory used for radioac-tive bio-assays. The Control Technology Laborato-ry, 44 m2 (471 ft2), is used for teaching and research on ventilation and respiratory protec-tion and houses an 11,000 cfm low-velocity wind tunnel for inhalable particle studies. This facility conducts research on the inhalability of large particles, 10-200 µm, and the perfor-mance of samplers for particles in this size range under low air velocity conditions, 0.1-2 m/s (0.2 to 4 mph).