American Industrial Hygiene Conference and Exposition, May 10-15, 2003, Dallas, Texas. Fairfax, VA: American Industrial Hygiene Association, 2003 May; :47
Workers in the metalworking, construction, and mining industries may receive excessive inhalation exposures to metals such as chromium, nickel, and zinc, which could cause adverse health effects. Portable X-ray fluorescence spectrometry can measure airborne metals collected on filter media within minutes of collection at these worksites, thereby facilitating exposure assessment and control strategies. Recent technological improvements have led to the introduction of a new generation of portable instruments capable of measuring a broader range of elements with greater precision and lower detection limits. A portable instrument using a miniature battery-powered X-ray tube as the radiation source was evaluated along with two instruments using conventional sealed radioactive sources. Limits of detection (in flg/cm2) for the analysis of cellulose ester filter media on a sealed source instrument with an early generation silicone detector, a sealed source instrument with a high resolution detector, and the X-ray tube instrument, respectively, were found to be 3.6, 2.9, and 2.0 for chromium; 2.0, 1.2, and 1.5 for nickel; 1.9, 1.1, and 1.0 for copper; 1.4,2.1, and 1.0 for zinc; 3.0, 0.9, and 0.5 for arsenic; and 1.1, 0.5, and 0.6 for lead. Analyses of thin film single element standards revealed the precision of the X-ray tube instrument to be up to 50% greater than that of sealed source instruments in the 15 to 150 ltg/cm2 concentration range. Transport and maintenance of the X-ray tube instrument is simple when compared to conventional sealed radioactive source instruments and the need to periodically replace the radioactive source and dispose of the associated hazardous waste is eliminated. The portable X-ray tube XRF is a practical innovation in this series of instruments, and portable XRF spectrometry continues to show promise as a fast, reliable, and comparatively inexpensive screening tool for monitoring and controlling airborne metal exposures.
American Industrial Hygiene Conference and Exposition, May 10-15, 2003, Dallas, Texas