for people ages 18-50 (full criteria)
Healthy Volunteers
healthy people welcome
at San Francisco, California
study started
completion around
Principal Investigator
by Suzaynn Schick
Headshot of Suzaynn Schick
Suzaynn Schick



This study compares the health effects of dermal and inhalational exposure to thirdhand cigarette smoke to those of inhalational exposure to secondhand cigarette smoke in healthy, adult nonsmokers. Our hypothesis is that dermal exposure increases exposure to the tobacco specific carcinogen, NNK and may affect both endothelial function and epidermal integrity.

Official Title

Controlled Human Exposure and THS Generation Core


Thirdhand cigarette smoke is the smoke chemicals that persist in the environment after smoking. Indoors, they can be found both on surfaces and in the air. Thirdhand smoke derives from secondhand smoke and contains the chemicals that stick to surfaces, are re-emitted into the air and that form by chemical reactions both on surfaces and in the air.

Thirdhand smoke can contain higher concentrations of the tobacco-specific nitrosamine and known carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) than secondhand smoke, because nicotine reacts to form NNK in the indoor environment. Dermal exposure to thirdhand smoke includes nicotine, NNK and other tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, and volatile organic compounds. Inhalational exposure to thirdhand smoke includes nicotine, ultrafine particles and volatile organic compounds. Previous studies have shown that inhalational exposure to secondhand cigarette smoke causes endothelial dysfunction, which is a risk factor for heart disease and heart attacks.


Pollution; Exposure, Smoke Inhalation, Exposure to Pollution, Smoke Inhalation Injury, Cigarette Smoke, Dermal Exposure to Thirdhand Cigarette Smoke, Inhalational Exposure to Thirdhand Cigarette Smoke, Inhalational Exposure to Secondhand Cigarette Smoke, Clean Air Exposure


You can join if…

Open to people ages 18-50

  • Healthy on the basis of medical history, blood pressure and test of C-reactive protein, lipids and blood sugar.
  • Non-smoker not exposed to second-hand smoke (SHS) as determined by saliva cotinine < 10 ng/ml and tetrahydrocannabinol (THC) < 50 ng/ml.
  • Flow mediated dilation of 4% or greater at screening visit.

You CAN'T join if...

- Age 18 < or > 50 Physician diagnosis of asthma, heart disease, hypertension, thyroid disease, diabetes, renal or liver impairment or glaucoma. Unstable psychiatric condition (such as current major depression, history of schizophrenia or bipolar disorder) or current use of more than two psychiatric medications Systolic blood pressure > 150 Diastolic blood pressure > 100 Blood glucose > 110 LDL >130 Pregnancy or breastfeeding (by urine Human Chorionic Gonadotropin (hCG) and/or history) Alcohol or illicit drug dependence within the past 5 years BMI > 35 and < 18 Current illicit drug use (by history or urine test) More than 1 pack year smoking history Ever a daily marijuana smoker Smoked anything within the last 3 months Unable to hold allergy or other over-the-counter (OTC) medicines Occupational exposure to smoke, dusts and fumes Concurrent participation in another clinical trial Unable to communicate in English No social security number


  • Zuckerberg San Francisco General Hospital
    San Francisco California 94110 United States

Lead Scientist at UCSF

  • Suzaynn Schick
    I study the health effects of air pollution in human subjects. I focus on the chemistry and toxicity of smoke and on how exposure to tobacco or cannabis smoke can cause heart and lung disease.


currently not accepting new patients, but might later
Start Date
Completion Date
University of California, San Francisco
Study Type
Expecting 66 study participants
Last Updated