Journal of Hazardous Materials 102 (2003) 29–38 Evaluation of two portable lead-monitoring methods at mining sites Pamela L. Drake a,∗ , Nicholas J. Lawryk b , Kevin Ashley c , Aaron L. Sussell c , Kyle J. Hazelwood a , Ruiguang Song d a US Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health (NIOSH), 315 E. Montgomery Avenue, Spokane, WA 99207, USA b US Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health (NIOSH), 1095 Willowdale Road, Morgantown, WV 26505, USA c US Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health (NIOSH), 4676 Columbia Parkway, Cincinnati, OH 45226, USA d US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for HIV, STD, and TB Prevention (NCHSTP), 1600 Clifton Road, NE, Atlanta, GA 30333, USA Abstract Two methods for measuring airborne lead using field-portable instruments have been developed by the National Institute for Occupational Safety and Health (NIOSH): Method 7702 uses X-ray fluorescence (XRF), and Method 7701 employs ultrasonic extraction (UE) followed by anodic stripping voltammetry (ASV). The two portable methods were evaluated at mining sites. Area air samples were collected throughout two mills where ore from nearby mines was processed; the primary constituent of the ore was lead sulfide (galena). The air samples were collected on 37 mm mixed cellulose ester membrane filters housed within plastic filter cassettes. At the end of the work shift, the cassettes were collected and taken to a room off-site for analysis by the two portable methods. The filter samples were first analyzed by XRF and then by UE/ASV. Calibration was verified on both instruments according to standard procedures. The samples were then sent for confirmatory analysis via flame atomic absorption spectrometry (FAAS) according to NIOSH Method 7082. Pairwise comparisons between the methods using the paired t-test showed no sta- tistically significant differences between ASV and FAAS (P> 0.05); however, the comparison between XRF and FAAS was statistically significant (P< 0.05). The elevated lead concentrations reported by XRF relative to FAAS were likely the result of the ability of XRF to report total lead, including lead silicates. This form of lead is not liberated in the digestion process prior to FAAS analysis, and is therefore not detected by this method. Despite this discrepancy, lead concentrations measured by both portable technologies were found to be highly correlated with the laboratory ∗ Corresponding author. Tel.: +1-509-354-8050; fax: +1-509-354-8099. E-mail address: pdrake@cdc.gov (P.L. Drake). 0304-3894/$ – see front matter. Published by Elsevier B.V. doi:10.1016/S0304-3894(03)00200-0