This document summarizes approaches for measuring secondhand smoke exposure. It discusses questionnaires, biological samples like cotinine and NNAL, and environmental samples like air nicotine and particulate matter. Questionnaires are commonly used but need accuracy testing. Biological samples indicate recent or long-term exposure but have limitations. Air nicotine and particulate matter monitors provide objective measures but have costs. The best approach depends on the study objectives, subjects, and resources. Further research is still needed to improve exposure assessment methods.

1. How do we Measure Secondhand Smoke Exposure?
Dr. Erika Avila Tang
Department of Epidemiology
Institute for Global Tobacco Control

2. FAMRI Expert SHSe Assessment
 Goal:
 To catalogue the approaches for Secondhand Smoke exposure (SHSe) assessment
 Provide a set of uniform methods for future use to facilitate comparisons of findings
across studies
 Comprehensive topic assessments on:
 Questionnaires and self-reported methods
 Biological samples
 Environmental samples
 Flight Attendant Medical Research Institute (FAMRI) Centers of Excellence
 American Academy of Pediatrics Julius B. Richmond, Illinois, USA
 Johns Hopkins University, Maryland, USA
 University of California, San Francisco Bland Lane, California, USA
 More than 20 researchers on SHSe assessment involved
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3. Why would we want to measure SHSe?
 SHSe is a key element of tobacco control
research and implementation worldwide
 To estimate the SHSe overall burden of disease
 To determine the risks associated with SHSe
 To assess population trends in support of and
evaluate tobacco control policies
 To support and evaluate behavioral interventions

4. Topic assessments
 Questionnaires and self-reported methods
 Biological samples
 Environmental samples
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5. Self-reported methods of assessment
 Questionnaires
 Most commonly used
 Inexpensive and feasible for large studies
 Assessment of :
 Current and long-term exposure
 Time-activity patterns
 Recall can be an issue
 Diaries
 Recall burden is reduced but respondent’s burden is increased
 E.g. Report over the past day vs. past week/month
 Higher awareness of instances of exposure

6. Accuracy: validity and reliability
 Review of studies assessing the validity and/or
reliability of questions
 Validation of questions against a “gold
standard”:
 Air measurement
 Biomarker
 Reliability=repeatability
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7. Conclusions for questionnaires and self-
reported methods
 Reliable responses for SHSe in their lifetime, childhood,
and current among adults.
 For children, CPD from parents, in their presence, and in
places
 Research on testing the accuracy of questions are still
needed
 Current exposure for adults and children, including intensity and
duration of exposure
 Exposure at home, in transport, and in social settings
 Collaboration of FAMRI CoEs: AAP Richmond, Johns
Hopkins, and UCSF Bland Lane are testing questions in
pilot studies to continue building a set of core questions
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8. Topic assessments
 Questionnaires and self-reported methods
 Biological samples
 Environmental samples
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9. Biomarkers
 Tobacco-specific biomarkers
 Cotinine
 Reflects recent SHSe (t1/2 16 hours (average))
 Nicotine/cotinine in hair or toenails
 Reflects “longer exposure”: 1 cm of hair proximal to the
scalp ≈ last month’s exposure; 1 mm ≈ last month’s
exposure
 NNAL (4-[methylnitrosamino]-1-[3-pyridyl]-1-butanol)
 Reflects “longer exposure” (t1/2 up to 3 weeks)
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10. Biomarker- Cotinine
Matrix Cut-off Pros Cons
Urine 50 ng/ml for higher Higher Need of facilities with
Non-invasive SHSe concentrations privacy during collection
than other Difficulty for population-
matrices based or children studies
(higher Need for creatinine
sensitivity) clearance adjustment
Collect data on renal
disease and some
prescription drugs
Blood 12 ng/ml for higher No adjustment Pregnant women have
Invasive SHSe required for increased clearance rate
hydration Difficulty for infants and
3 ng/ml for lower young children
SHSe Lower sensitivity
Saliva 14 ng/ml for higher Good for Potential issues with age,
Non-invasive SHSe multiple gender, race, oral pH, type
measurements of diet, dehydration, or
over a limited drug treatment
period of time Lower sensitivity
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11. Biomarker- Nicotine/Cotinine
Matrix Cut-off Pros Cons
Hair 0.8 ng/mg Easy to collect, ship, and Scarcity of hair in infants
Non-invasive (Women) store (room temperature ≤ 5 and adults
years) Chemical hair treatments
0.2 ng/mg Less affected by daily can reduce concentrations
(Pregnant) variability (fluctuating by 9%-30%
exposure, varying Age, gender, and race may
0.2 ng/mg metabolism, and nicotine play roles in determining
(Children) elimination) hair nicotine concentrations
Represents longer exposure
Toenails Not Easy to collect, ship, and Need for further research
Non-invasive available store (room temperature ≤ and population
20 years) concentrations
Overcomes day-to-day
exposure variability
Represents longer exposure
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12. Biomarker- NNAL
Matrix Cut-off Pros Cons
Urine Not Related to a lung carcinogen Analytical expertise
available Represents longer exposure Costly equipment
than cotinine NNAL is carcinogenic and
(urine/blood/saliva) mutagenic, special lab
handling
Further research needed
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13. Topic assessments
 Questionnaires and self-reported methods
 Biological samples
 Environmental samples
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14. Environmental measurements
 Most widely used methods:
 Nicotine: passive air monitor
 Particulate matter (< 2.5µ (PM2.5)) monitor
 Correlation between nicotine and PM when
measured in the same setting using a common
sampling period
 An increase in 1 µg/m3 of nicotine concentration ≈ an
average increase of 10 µg/m3 of PM
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15. Air nicotine monitoring
 Highly specific to tobacco smoke
 Monitors (1-3) placed in each venue (hung from the
ceiling) for 5 to14 days
 Filters are soaked in a bi-sodium sulfate solution that
captures nicotine on the filter
 No expensive equipment to buy
up front and minimal operating
cost but requires lab analysis
 Per sample laboratory costs
including the filter badge are
~$40-$100 USD

16. Particulate matter monitoring
 Active, real-time monitor
 Uses light scattering to measure particulate
matter concentrations (e.g. PM2.5)
 Air quality standards makes easier
dissemination
 Other causes of indoor air particles
 High initial investment
 ~3,000 USD
 Minimal operating cost
 No per sample costs
 Potential costs in labor for data analysis

17. Overall findings
 Questionnaires are the most effective way to know if
people are exposed – but not how much they are exposed
 Research on testing the accuracy of questions are still
needed
 Choice of any SHSe assessment method depends on your
needs
 Study’s objectives, subjects, design and setting and funding
 Selection of a biomarker will dependent on:
 Issues of privacy, invasiveness, and subject’s age
 The length of SHSe may result in selecting hair or toenails over bio-
fluids
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18. Acknowledgements
Wael Al-Delaimy Melbourne Hovell
Benjamin Apelberg Andrew Hyland
David Ashley Sungroul Kim
Erika Avila-Tang Jonathan Klein
Neil Benowitz Neil Klepeis
Thomas Bernert Robert McMillen
Dana Best James Repace
Patrick Breysse Jonathan Samet
Michael Cummings Jonathan Winickoff
Geoffrey Fong Ana Navas-Acien
Lara Gundel Lisa Hepp
Kathie Hammond Jessica Elf
Stephen Hecht Camille Madsen
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