Controlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke

NCT ID: NCT04013256

Last Updated: 2023-08-28

Basic Information

• Recruitment Status: SUSPENDED
• Clinical Phase: NA
• Total Enrollment: 66 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-01-20
• Study Completion Date: 2024-10-31

Brief Summary

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.

Detailed 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.

Conditions

Pollution; Exposure; Smoke Inhalation; Exposure to Pollution

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Dermal Exposure to Thirdhand Cigarette Smoke

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

Group Type: EXPERIMENTAL

Cigarette Smoke

Intervention Type: OTHER

Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.

Inhalational Exposure to Thirdhand Cigarette Smoke

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

Group Type: ACTIVE_COMPARATOR

Cigarette Smoke

Intervention Type: OTHER

Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.

Inhalational Exposure to Secondhand Cigarette Smoke

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

Group Type: ACTIVE_COMPARATOR

Cigarette Smoke

Intervention Type: OTHER

Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.

Clean Air Exposure

Participants will breathe filtered, temperature and humidity controlled air while wearing clean clothing for 3 hours.

Group Type: SHAM_COMPARATOR

Clean Air and Clean Clothing/Sham exposure

Intervention Type: OTHER

Clean air, created by high-efficiency particulate air (HEPA) and charcoal filtration and temperature and humidity control.

Clean cotton clothing.

Interventions

Cigarette Smoke

Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.

Intervention Type: OTHER

Clean Air and Clean Clothing/Sham exposure

Clean air, created by high-efficiency particulate air (HEPA) and charcoal filtration and temperature and humidity control.

Clean cotton clothing.

Intervention Type: OTHER

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Tobacco Related Disease Research Program

OTHER

Sponsor Role: collaborator

University of California, San Francisco

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Suzaynn F Schick, PhD

Role: PRINCIPAL_INVESTIGATOR

University of California, San Francisco

Locations

Zuckerberg San Francisco General Hospital

San Francisco, California, United States

Countries

United States

Other Identifiers

28PT-0081

Identifier Type: -

Identifier Source: org_study_id