AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
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An Automated Microenvironmental Aerosol Sampler (AMAS) For Location/Activity Exposure Assessment
CASEY QUINN, Dan Miller-Lionberg, Jaruwan Mettakoonpitak, John Mehaffy, Sheryl Magzamen, Charles Henry, John Volckens, Colorado State University
Abstract Number: 568 Working Group: Aerosol Exposure
Abstract Existing methods for assessing time-integrated personal exposure are cumbersome and relatively expensive, especially in the context of large-scale epidemiological studies. To address these limitations, we developed an automated microenvironmental aerosol sampler (AMAS). The AMAS is a low-cost, wearable device containing four separate filter channels. A novel aspect of this device is that it collects particulate matter from within distinct personal microenvironments (such as at home, at work, and in transit). The AMAS is about the size of a cell phone, weighs 220 g, and can sample continuously for 32 or 12 hrs on a single charge at 1 or 2 L/min of flow, respectively. The device operates autonomously, using data from on-board sensors (GPS, light intensity, temperature, acceleration) to determine when an individual enters or leaves a given microenvironment and then initiates sampling through one of the four filter channels. A custom-designed manifold utilizing miniature valves was used in conjunction with the AMAS sensor algorithm to control sample flow through a given filter channel. A pilot study was conducted for two weeks with 25 grade-school children to collect samples to demonstrate the feasibility of the sampler and to validate performance. Square-wave anodic stripping voltammetry, electrochemical paper-based analytical devices (ePADs), and image processing were used to quantify levels of zinc, cadmium, and lead collected on the AMAS filters, while particulate black carbon was quantified using optical transmissometry. These analytic techniques provide rapid, low-cost analyses, with method detection limits that are relevant to environmental concentrations: zinc [8.86 ng/m$^3 LOD]; cadmium [0.885 ng/m$^3 LOD]; lead [0.177 ng/m$^3 LOD]. The AMAS and epAD techniques were evaluated using traditional analytical techniques (ICP-MS) and personal samplers (SKC PEM, BGI OMNI 3000). Preliminary results indicate that the AMAS can is a feasible approach for low-cost, personal exposure assessment across various microenvironments.