Airborne heavy metal monitor.
Fraser-ME; Hunter-AJR; Panagiotou-M; Davis-SJ
NIOSH 1998 May; :1-29
For the Phase I program, Physical Sciences Inc. (PSI) proposed to develop a simple, inexpensive, compact, real-time optical diagnostic for the measurement of metals in airborne aerosols and particulates. During the Phase I effort, key issues of sensitivity and calibration were to be explored and a prototype monitor for lead constructed and tested. The objectives of the proposed Phase I program were outlined in the proposal as follows: 1) build a simple, fieldable monitor for lead-laden aerosols based on PSI's experience with spark-induced breakdown spectroscopy; 2) calibrate the monitor with lead-containing aerosols generated by PSI's in-house dry aerosol generator; and 3) test the unit offsite at a firing range. PSI has successfully accomplished this statement of work. Highlights of our achievements are summarized here. PSI assembled a fully functional lead monitor. The unit is composed of a spark power supply, spark and sample chamber, radiometer detection package, and computer for data acquisition and display. The system has been calibrated over the range 10 ppbw to 10 ppmw using a gravimetrically-determined dry aerosol generator (1 ppbw equivalent to 1.2 microg/m3). The 3 times the standard deviation detection limit is 8 ppbw. Further optimization of the detection system could yield another order of magnitude in detection limit..The calibration has been shown to be independent of the chemical forms of lead tested. Tested compounds include lead nitrate, lead chloride and lead acetate. Our detection scheme has been proven to be free of potential spectral interferences from iron, silicon, aluminum, magnesium and potassium. The functionality of the lead monitor has been tested in-house by detecting the lead from handgun blanks containing lead styphnate primer. Simultaneous data from the monitor and lead collected on an internal filter (analyzed by an environmental laboratory) compare well. The lead monitor has been tested twice at a local, modern firing range. These tests have included measurements in the immediate vicinity of the shooting booths and downrange in the ventilation crawlspace before the lead-laden air enters the scrubbers. The data correlate well with shooting events and the observed concentrations are consistent with typical levels reported in the literature.
Airborne-particles; Heavy-metals; Monitoring-systems; Monitors; Measurement-equipment; Metal-compounds; Metal-dusts; Metals; Lead-compounds; Sensitivity-testing; Spectroscopes; Aerosol-generators; Lead-dust
Physical Sciences Inc., 20 New England Business Center, Andover, MA 01810
301-04-2; 7439-92-1; 7758-95-4; 10099-74-8
Final Grant Report
Research Tools and Approaches; Exposure Assessment Methods
National Institute for Occupational Safety and Health
Physical Sciences Inc., Andover, Massachusetts