On-site measurement of blood-lead concentrations using field-portable electroanalysis.

Abstract

The health effects of lead exposure are well documented. Lead can be inhaled into the lungs, absorbed through the skin, or ingested from contaminated hands, food, or cigarettes. Because air samples are not a surrogate for biological monitoring, Occupational Safety and Health Administration (OSHA) regulations mandate that employees’ bloodlead levels be tested regularly.1 Given the high potential for surface contamination, venous samples are considered the primary method for blood-lead testing in occupationally exposed individuals. Currently, OSHA regulations do not mandate a speciŽ c analytical method for blood-lead analysis. Instead, successful participation in an ongoing proŽ ciencytesting program is necessary to remain CLIA(Clinical Laboratory Improvements Amendment2) certiŽ ed and OSHA-approved in blood-lead analytical techniques. CLIA mandates that a blood-lead analysis laboratory must report proŽ ciency testing results within §4 1g/dL (§0.19 1mol/L) or within 10 percent, whichever is greater, of the target (true) value.2 In recent years, different technologies have been investigated for their utility as portable blood-lead analysis instruments. Portable instruments are potentially useful because they provide immediate results and the opportunity for immediate intervention, if necessary. Instruments involving both Potentiometric Stripping Analysis (PSA) and Anodic StrippingVoltammetry (ASV) have been explored.3 An instrument utilizing PSA is in commercial development by Intelab Corporation (Mission Viejo, CA). Although some preliminary Ž eld evaluations have been conducted with the PSA instrument, this device has not been submitted for FDA (Food and Drug Administration) market clearance.4 Hence, this article discusses only anASV instrument that has received market clearance. ESA, Inc. (Chelmsford, MA) and AndCare, Inc. (Durham, NC) developed a small, rapid, handheld portable instrument utilizing ASV. This device, named the LeadCare°R instrument, has received 510(k) market clearance from the FDA and has been classiŽ ed under CLIA as a moderately complex medical diagnostic device.5 It has been used with success during pediatric screening programs.6 However, blood-lead levels in children are generally signiŽ cantly lower than the blood-lead levels normally present in occupationally exposed adults. Thus, it was of interest to evaluate the portable blood-lead monitor in worker populations where lead exposures are encountered.