Evaluation of a personal air sampler for twenty-four hour collection of fine particles and semivolatile organics1

Abstract

The U.S. EPA has conducted an evaluation of a commercially available lightweight fine particle personal sampler for use in human exposure and Ž . biomarker studies involving 24-h collections of particulate matter, particle-bound organics such as polycyclic aromatic hydrocarbons PAHs , and Ž . semivolatile organics PAHs . Independent laboratory evaluation of the prototype design, intended to produce a 2.5-mm aerodynamic diameter cut-point at Ž . Ž . a flow between 1.5 and 1.7 lpm liters per minute , indicated that at a challenge flow rate of 1.5 lpm, the sampler provided an aerodynamic cut-point dp 50 of only 1.7 mm. The variance between expected size selection resulted from the prototype's jet diameter dimension being inadvertently based upon a flow rate of 2.0 lpm rather than an intended 1.5-1.7 lpm. Other aerodynamic factors not presently accounted for may also have played an influence. Extrapolated cut-points for flow rates at 1 and 3 lpm for the prototype were determined to be 2.1 and 1.2 mm, respectively. Total losses attributed to unwanted particle retention within the sampler ranged from 10% for 0.91 mm size particles to essentially zero approaching diameters greater than 2.0 mm.Ž . The ambient concentration of particles -1.7 mm needed for acceptable gravimetric filter measurements involving 24-h sample collection was determined to be 10 mgrm 3 . Investigation of the sampler to retain and recover PAHs using XAD-2 resin, often of importance in human exposure biomarker studies, indicated that corrected recoveries between 94% and 108% could be obtained for 16 priority pollutant PAH species. Overall evaluation of the personal monitor indicates that it has research utility due to its modular features and size but reconfiguration should be performed that would permit true PM size 2.5 selection. The current configuration collects particles less than 2.5 mm at approximately 95% collection efficiency.

Personal exposure to carcinogenic polycyclic aromatic hydrocarbons in the Czech Republic

“…27 The sampler was connected to a pump operating at 1.7 l/min powered by batteries with inlet attached to the individual's breathing zone and was located by his bed during the night (total weight of the sampler 1 kg). 28…”

The design and field implementation of the Detroit Exposure and Aerosol Research Study

“…An intensive 5-year research effort to further this goal was conducted beginning in 1998 using guidance from the National Research Council (NRC, 1998). One major component of this effort involved longitudinal human exposure panel studies in an effort to better understand the contribution of particulate matter (PM) of ambient origin to total personal exposures over time (Williams et al, 1999;Evans et al, 2000;Williams et al, 2000a, b, c, d;Williams et al, 2002Williams et al, , 2003aWallace and Williams, 2005;Wallace et al, 2006a, b;McBride et al, 2007). Results from these studies showed that for fine PM mass and sulfate, a central monitoring site could serve as an adequate surrogate for exposure in community-based epidemiological studies (US EPA, 2004).…”

Epidemiologic evidence for asthma and exposure to air toxics: linkages between occupational, indoor, and community air pollution research.

“…Latex allergen found on respirable rubber tire particles is likely common in urban air (125,126) and could lead to sensitization and respiratory symptoms. In addition, the physical action of motor vehicles on road dust, which is known to contain pollen grains, could lead to the production and resuspension of smaller respirable pollen fragments (37).…”