AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Quantifying Exposure to Second Hand Tobacco Smoke in the Presence of Black Carbon via DualSpot Corrections to MicroAeth Data: Results from Chamber Experiments
ABDERAHIM SALHI, James Ross, Beizhan Yan, Qiang Yang, Jeanine D’Armiento, Jarrod Sonnett, Matthew Perzanowski, Steven Chillrud, Hudson County Community College; LDEO of Columbia University
Abstract Number: 913 Working Group: Instrumentation and Methods
Abstract Second hand tobacco smoke (SHS) is associated with an array of adverse health effects making it an important exposure to measure. However, significant shortcomings exist for current methods such as self-reported questionnaires, cotinine/nicotine biomarkers, and airborne tracers such as nicotine. Multi-wavelength absorption methods of integrative filters collected over days to weeks have been promoted but are significantly impacted when moderate to elevated black carbon (BC) loadings are present, which suppress the ultraviolet (UV) signature of the biomass particulate matter (PM). The multi-wavelength microAeth MA350 (AethLabs) includes the option for carrying out DualSpotTM loading corrections on each wavelength-based absorption on highly time resolved data. DualSpot corrections for black carbon have been evaluated through comparison to in situ BC methods such as photoacoustic extinctiometers. As far as we are aware, no-one has evaluated DualSpot corrections under controlled conditions for biomass smoke sources such as SHS. Our chamber experiments mixed SHS from a cigarette machine with ethylene-based BC soot from an inverted flame source to characterize the loadings necessary to suppress the uncorrected UV signature. Then DualSpot corrected data are compared to uncorrected data to evaluate the correction under controlled conditions of near-constant inputs of SHS and BC over time. Black carbon loading significantly suppresses the uncorrected SHS signal starting at around 2 IR ATN units, reaching a suppression of ~40% by 8 IR ATN units. DualSpot correction appears to completely remove the loading effect of BC on the optical signature of SHS as long as the unit has good flow control, with flow on spot 1 (100 ml/min) needing to be 2.0 times that of the flow on spot 2 (i.e. 50 ml/min). Future work should focus on gravimetric calibration of the ∆UVPM signature of SHS through collection of filters.