Presentation on theme: "Comparing Methods for the Real- Time Measurement of Secondhand Tobacco Smoke Particles Neil E. Klepeis Visiting Scholar, Stanford University, Department."— Presentation transcript:
Comparing Methods for the Real- Time Measurement of Secondhand Tobacco Smoke Particles Neil E. Klepeis Visiting Scholar, Stanford University, Department of Statistics
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?
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
Real-Time Particle Monitoring Instruments, Part I A. Nephelometer (Radiance) B. Piezobalance (TSI/Kanomax) C. PAH (Ecochem) D. Laser Counter (GRIMM) E. CO (Langan)
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)
Reference Measure: Piezobalance Versus Filter Mass for Cigarettes and Incense
Evolution of the Secondhand Smoke Aerosol Size Distribution
Field Exposure Studies
Outdoor Restaurants and Pubs with Smokers
Outdoor Hookah Restaurant
Blowing Hookah Smoke Into Monitors Cigarette Smoke
Controlled Exposure Studies
Outdoor Proximity Experiments
3D Monitoring Array to Study Outdoor Proximity and Wind Effects
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?
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
Suite 4 Bedroom Experiments
Are Two Instruments of the Same Type Consistent?
Two Matched Piezobalances
Consistency Between Two Light Scattering Instruments
Are Measurements Consistent Across Experiments on Different Days?
Can Measurements be Reliably Converted to Respirable Particle Mass (Piezobalance)?
SidePak Factory Calibration Certificate
Piezobalances and SidePak (Factory-Calibrated) Elapsed Minutes
Piezobalance Versus SidePak Regression
Piezobalance and SidePak (Custom-Calibrated)
Summary and Conclusions
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%)
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
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: n Web:
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
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