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Comparing Methods for the Real- Time Measurement of Secondhand Tobacco Smoke Particles Neil E. Klepeis Visiting Scholar, Stanford University, Department of Statistics http://Klepeis.Nethttp://ExposureScience.Orgneil@klepeis.net
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Background Issues: Real-Time Particle Instruments n Can these instruments be used to characterize secondhand smoke? n Are they sensitive? n Are they convertible to standard measures? n Are they reliable and consistent?
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Addressing the Issues n Field Studies of Secondhand Smoke Exposures n Controlled Studies of Exposure Factors n Controlled QA Studies Systematically Comparing and Evaluating Instruments
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The Instruments
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Real-Time Particle Monitoring Instruments, Part I A. Nephelometer (Radiance) B. Piezobalance (TSI/Kanomax) C. PAH (Ecochem) D. Laser Counter (GRIMM) E. CO (Langan)
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Real-Time Particle Monitoring Instruments, Part II A. Laser Counter (Met-One) B. SidePak (TSI) C. PC/DC (Ecochem & Siegmann) D. Ultrafine 3007 CPC (TSI)
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Reference Measure: Piezobalance Versus Filter Mass for Cigarettes and Incense
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Evolution of the Secondhand Smoke Aerosol Size Distribution
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Field Exposure Studies
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Outdoor Restaurants and Pubs with Smokers
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A Cigar
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Outdoor Hookah Restaurant
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Blowing Hookah Smoke Into Monitors Cigarette Smoke
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Controlled Exposure Studies
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Outdoor Proximity Experiments
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Indoor-Outdoor Comparison
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3D Monitoring Array to Study Outdoor Proximity and Wind Effects
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Automobile Monitoring
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QA Studies
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Consistency and Correspondence n Do different monitors of the same type match each other? n Does the same monitor react the same on different days when using the same source and the same or different environmental conditions? n Can readings from one type of monitor be used to predict those of another? n Is the relationship between monitors of different types the same under different conditions, time scales, etc?
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Four Suites of Side-by-Side QA Experiments (1). 31 Cigarette & Incense Experiments: Commercial Location; Grimm, Ecochem, Filters, Piezobalance (2). 7 Cigarette Experiments: Residential 44 m 3 Bedroom; MIE DataRam, Ecochem, Piezobalance, Humidity, Temperature (3). 5 Cigarette Experiments: Residential 44 m 3 Bedroom; Grimm, Ecochem, Piezobalance, Nephelometers. (4). 15 Cigarette Experiments: Residential 44 m 3 Bedroom; Grimm, Ecochem, PC/DC, Piezobalance, Nephelometers, SidePak, Humidity, Temperature
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Suite 4 Bedroom Experiments
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Are Two Instruments of the Same Type Consistent?
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Two Matched Piezobalances
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Consistency Between Two Light Scattering Instruments
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Are Measurements Consistent Across Experiments on Different Days?
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Can Measurements be Reliably Converted to Respirable Particle Mass (Piezobalance)?
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SidePak Factory Calibration Certificate
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Piezobalances and SidePak (Factory-Calibrated) Elapsed Minutes
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Piezobalance Versus SidePak Regression
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Piezobalance and SidePak (Custom-Calibrated)
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Non-Linear Effects
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Summary and Conclusions
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Summary and Conclusions: Instrument Evaluation n Real-time instrument measurements can be related to standard methods and are generally sensitive, consistent, dependable, and quantitative indicators of tobacco smoke concentrations. n Matched instruments are very comparable, e.g., for use in studies of relative exposures n Factory calibrations of aerosol monitors cannot be assumed to be reliable for application to SHS n Two instruments analyzing different aerosol components and sizes may have a nonlinear relationship when including both fresh and aged aerosol n Light scattering instruments have a linear relationship to respirable mass, with an associated conversion factor n Instrument responses and relationships vary by composition and size of particle emissions n Relative humidity appears to have a small effect (50 to 75%)
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Future Work on Real-Time Particle Monitoring n Formalize Central Tendency and Variability in Instrument Interconversion Factors n More Side-by-Side Comparison of Instrument Responses in the Field n Consider Mixture of Cigarette Types n Use Real Smokers
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Upcoming Report on Instrument Evaluation n Detailed description of all experiments n Results of all instrument comparisons n Best estimates of instrument conversion factors n Contact: neil@klepeis.net n Web: http://ExposureScience.Org
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Last Words n Real Time Methods Allow us to Identify the Impact of Specific Minute-by- Minute Changes in Environmental Conditions and Human Behavior on Exposure n Unique Tool to Judge the Effectiveness of Exposure Reduction Measures n Immediate and Dramatic Feedback for Interventions n Development of Educational Materials
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Acknowledgements n Wayne Ott, Stanford University n James Repace, Repace Associates n Paul Switzer, Stanford University n Lynn Hildemann, Stanford University n California Proposition 99, UCSF n Tobacco-Related Disease Research Program of California (TRDRP) n Flight Attendant Medical Research Institute (FAMRI) in Miami, FL n U.S. Environmental Protection Agency
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