title: Laboratory evaluation of a physiologic sampling pump (PSP).
abstract: Recently, physiologic sampling pumps (PSPs), which can adjust their sampling rates in proportion to wearers' minute ventilation (V[combining dot above](E)), have been proposed to better estimate exposure to airborne contaminants in the workplace. A laboratory evaluation was conducted to compare the performance of a new PSP with a traditional sampling pump (TSP) in an exposure chamber. Fifteen subjects (aged 19-36 years) performed two replicate sessions of step-tests for correlated and uncorrelated exposure scenarios on four separate days. When exposed to a scenario in which subject V[combining dot above](E) is highly correlated with m-xylene concentration over the sampling period (r = 0.93), the PSP-measured time-weighted average (TWA) concentrations are higher than TSP-measured concentrations (average ratio of PSP to TSP = 1.18). The ratio of PSP- and TSP-measured TWA concentrations for the uncorrelated scenario (r = 0.02) is closer to one, as expected, with an average value of 0.94. The test results of the linear mixed model further indicate that the performance of the PSP is unaffected by the anthropometric and physiological characteristics of the wearer. Potential differences in exposure estimates resulting from the use of the two instruments were examined in light of various schemes which can potentially occur in the field. With the capability of estimating the total volume of air inhaled over the sampling period with improved accuracy, PSPs show promise in reducing the inherent uncertainty in current risk assessment approaches that entail constant-flow (TSP) sampling approaches.
authors.affiliation: The National Cheng Kung University, Tainan, Taiwan 701. brandonl@mail.ncku.edu.tw
authors.forename: Ming-I Brandon
authors.initials: MI
authors.lastname: Lin
authors.forename: William A
authors.initials: WA
authors.lastname: Groves
authors.forename: Andris
authors.initials: A
authors.lastname: Freivalds
authors.forename: Larry
authors.initials: L
authors.lastname: Lee
authors.forename: Eun Gyung
authors.initials: EG
authors.lastname: Lee
authors.forename: James E
authors.initials: JE
authors.lastname: Slaven
authors.forename: Martin
authors.initials: M
authors.lastname: Harper
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis*; D001273:Atmosphere Exposure Chambers; D004784:Environmental Monitoring / Q000295:instrumentation*; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D008297:Male; D055815:Young Adult
chemical_list: D000393:Air Pollutants