Monitoring Airborne Levels of Outdoor and In-Vehicle Secondhand Tobacco Smoke

Neil E. Klepeis, Ph.D.Human Exposure Research Associate

Stanford University, Stanford, CAhttp://klepeis.net, http://exposurescience.org

Why Monitor Secondhand Smoke?

● Judge severity of exposure● Communicate risks● Encourage smoking restrictions and bans● Identify exposure reduction measures● Establish disease association (epidemiology)

Why Monitor Outdoors andin Cars?

● Last frontiers for smoking bans● Very few studies available● How high can outdoor levels really be?● Practical Questions

What if I open my car window or use the ventilation during smoking?

What if I smoke near my child outdoors?

Environmental Health CycleExposure Science

Epidemiology

Toxicology

Public Health

Education/Outreach

Policy

Engineering

Direct Link to Tobacco ControlExposure Science

Epidemiology

Toxicology

Public Health

Education/Outreach

Policy

Engineering

What's in this Talk?

● Introduce Air Monitoring Instruments

● New Outdoor SHS Surveys and Experiments

● New In-Vehicle SHS Experiments

● Predictive Modeling of SHS Exposure and Risk

Portable Airborne Particle Monitoring Instruments

A. Laser Counter; B. SidePak Laser Photometer; C PC/DC Monitor;D. Condensation Nucleii Counter

A. Nephelometer; B. Piezobalance;C PAH Analyzer; D. Laser Particle Counter; E. CO Sensor

Outdoor Secondhand Smoke

Monitoring in Sidewalks Cafes, Parks, Pubs, Restaurants

Visits to Sidewalk Cafes & Restaurants

● 10 Locations

● 2000 minutes of continuous measurements

● Natural Human Smokers

● Controlled Smoking

Experiments with a Real Smoker

SidePak Monitor

Air Speed Monitor

Air Speed Monitor

Elevated Levels Near the Smoker

0.5 m 252 g/m3

0.5 m 233 g/m3

0.5 m 222 g/m3

0.8 m 127 g/m3

2.0 m 41 g/m3

2.0 m 14 g/m3

3.7 m 14 g/m3

3.7 m 5 g/m3

Burning Cigarette Experiments

Elevated Downwind Levels from a Smoker

0.3 m 582 g/m3

0.6 m 130 g/m3

0.9 m 127 g/m3

0.6 m 2 g/m3

1.2 m 41 g/m3

2.7 m 13 g/m3

Controlled Patio Experiments

Air Monitor Assemblies on Either Side of a Burning Cigarette

The Proximity Effect

Summary of Outdoor Results

● Being downwind from a smoker is the critical factor

● Levels drop off dramatically beyond 2 meters from a smoker – although levels can still be detected as far away as 9 meters or more.

● Being close to and downwind from an active smoker can lead to very high transient levels

● Short-term outdoor levels can exceed secondhand smoke levels measured inside smoking cars and houses

In-Vehicle Secondhand Smoke

Monitoring in Passenger Cars and SUV's

Vehicle Air Exchange Rates● 85 Air Changes● Five Vehicles● Tracer Gas Releases

● Five Driving Speeds ● Window Positions● Ventilation Settings

Air Exchange as a Function of Car Speed

Experiments In Cars with Smokers● 3 Rented Vehicles● 2 Smokers● 14 Cigarettes● Particle/CO monitoring

● Five Speeds● Window Positions● Ventilation Settings

Levels Inside a Car with a Smoker

A. Ford Taurus, 20 mph

B. Ford Taurus, 60 mph

AA

BB

Predicting In-Vehicle Levels

Levels are well predicted using a mathematical mass balance model.

Simulation of Levels in a Car

Rapid Feedback and Flexible Educational Tool

Summary of In-Vehicle Results● Opening windows increases the air exchange

rate by a factor of 10● Air exchange rate of car increases with speed● Smoking in a closed car results in extremely

high levels that are about 10 times higher than those measured in smoking homes

● Short-term levels with windows open or active ventilation can still approach levels found in smoking homes

● Levels in cars can be characterized using mathematical models

Practical Modeling of Daily (24-h) Exposure and Risk: Fine Particles

68 g/m3

106 g/m3

65 g/m3

41 g/m3

AmbientAmbient OutdoorsOutdoors CarCar USEPAUSEPAUnhealthy 17 Cigarettes 2 Cigarettes PM-2.5Unhealthy 17 Cigarettes 2 Cigarettes PM-2.5

Sens. People Downwind Closed/Moving StandardSens. People Downwind Closed/Moving Standard

Resources

ExposureScience.OrgExposureScience.Org

Downloadable Reports, Articles, and Software Related to Secondhand Tobacco Smoke Exposure in Cars, Homes, and the Outdoors

SimSmoke.OrgSimSmoke.Org

On-line Simulation of Secondhand Smoke Exposures in Indoor and Outdoor Settings

Acknowledgments

● Wayne Ott, Stanford University (Co-Investigator)● Paul Switzer, Stanford University (Principle

Investigator)● Grant from the Flight Attendant Medical

Research Institute (FAMRI)● Grant from California Proposition 99● Past Grant from Tobacco-Related Disease

Research Program (TRDRP)