NCT04013256

Controlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke

Controlled Human Exposure and THS Generation Core

• Status: Suspended
• Phase: N/A
• Study type: Interventional
• Enrollment: 66 (estimated)
• Sponsor: University of California, San Francisco · Academic / Other
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

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

Interventions

Type	Name	Description
OTHER	Cigarette Smoke	Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.
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.

Timeline

• Start date: 2020-01-20
• Primary completion: 2024-10-31
• Completion: 2024-10-31
• First posted: 2019-07-09
• Last updated: 2023-08-28

Locations

1 site across 1 country: United States