Controlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke (THS04)

University of California San Francisco (UCSF)

Status

Suspended

Conditions

Pollution; Exposure

Exposure to Pollution

Smoke Inhalation

Treatments

Other: Clean Air and Clean Clothing/Sham exposure

Other: Cigarette Smoke

Study type

Interventional

Funder types

Other

Identifiers

NCT04013256

28PT-0081

Details and patient eligibility

About

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.

Full description

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.

Enrollment

66 estimated patients

Sex

All

Ages

18 to 50 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

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.

Exclusion criteria

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

Trial design

Primary purpose

Basic Science

Allocation

Randomized

Interventional model

Crossover Assignment

Masking

None (Open label)

66 participants in 4 patient groups

Dermal Exposure to Thirdhand Cigarette Smoke

Experimental group

Description:

Participants will wear clothing that has been exposed to cigarette smoke, for 3 hours while breathing filtered, temperature and humidity controlled air.

Treatment:

Other: Cigarette Smoke

Inhalational Exposure to Thirdhand Cigarette Smoke

Active Comparator group

Description:

Participants will breathe cigarette smoke aerosol that has been aged for 22 hours, for 3 hours while wearing clean clothing.

Treatment:

Other: Cigarette Smoke

Inhalational Exposure to Secondhand Cigarette Smoke

Active Comparator group

Description:

Participants will breathe cigarette smoke aerosol that has been aged for 30 minutes, for 3 hours while wearing clean clothing.