Thirdhand Smoke Exposure for Healthy Subjects

(THS05 Trial)

Overseen By Abel Huang, BS

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of California, San Francisco

Must not be taking: Psychiatric medications

Disqualifiers: Asthma, Heart disease, Hypertension, Diabetes, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to study how skin color affects nicotine absorption from cigarette smoke into the skin. Participants will wear clothes exposed to cigarette smoke to determine if nicotine absorption varies with different skin tones. The trial includes two groups: one for individuals with lighter skin and another for those with darker skin. It seeks healthy, non-smoking adults aged 18-50 who have not been exposed to tobacco smoke recently. As an unphased trial, this study allows participants to contribute to important research on the influence of skin tone on nicotine absorption.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it excludes those using more than two psychiatric medications or unable to hold allergy or other over-the-counter medicines.

What prior data suggests that wearing clothing exposed to cigarette smoke is safe for healthy subjects?

Research shows that thirdhand smoke can be harmful. This refers to the tobacco smoke that lingers on clothes, furniture, and other surfaces after a cigarette is extinguished. Studies have found that prolonged exposure to these smoke residues can damage cells and DNA, potentially leading to health issues like asthma and cancer. Although this study involves wearing clothes exposed to cigarette smoke for a short period, it's important to understand that no amount of tobacco smoke is completely safe. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores the impact of thirdhand smoke on people with different skin melanin levels. Unlike other studies that focus on direct smoking effects, this trial investigates how smoke residue on clothing might affect the skin, which is a less understood area. By analyzing how different skin types respond to thirdhand smoke exposure, the trial aims to uncover potential health risks and provide insights for better public health recommendations.

What evidence suggests that wearing clothing exposed to cigarette smoke is effective for studying nicotine uptake and retention?

Research has shown that thirdhand smoke, the residue from tobacco smoke on surfaces, can be harmful. Long-term exposure to these pollutants can damage human cells and DNA. This exposure links to serious health problems like asthma and cancer. The trial will compare how skin color affects the amount of nicotine from thirdhand smoke that enters and remains in the body. Participants in the "Low melanin" arm will have skin reflectance scores below 150, while those in the "High melanin" arm will have scores above 249. Early findings suggest that melanin, the pigment in skin, might influence this process. Higher melanin levels could mean less nicotine is absorbed but stays longer in the skin. ^{1 2 4 5 6}

Who Is on the Research Team?

Suzaynn F Schick, PhD

Principal Investigator

University of California, San Francisco

Are You a Good Fit for This Trial?

This trial is for healthy adults aged 18-50 with specific skin reflectance scores, normal blood pressure, cholesterol, liver and kidney function. Smokers or those exposed to smoke are excluded, as well as individuals outside the BMI range of 18-35 or with certain medical conditions.

Inclusion Criteria

You are an adult who does not smoke.

According to your medical history, you are in good health.

You have not been exposed to secondhand smoke from tobacco products.

Exclusion Criteria

You have a job where you are regularly exposed to smoke, dust, or fumes.

I do not have an unstable psychiatric condition or use more than two psychiatric medications.

Concurrent participation in another clinical trial

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Exposure

Participants are exposed to smoke-exposed clothing to study dermal uptake and retention of nicotine

1 day

1 visit (in-person)

Monitoring

Blood concentrations of nicotine are measured before and after exposure

3 hours

1 visit (in-person)

Follow-up

Participants are monitored for nicotine metabolites in urine for 10 days after exposure

10 days

What Are the Treatments Tested in This Trial?

Interventions

• Wear clothing exposed to cigarette smoke

Trial Overview The study investigates how melanin in the skin affects absorption and retention of nicotine from clothes exposed to cigarette smoke. Participants will wear these clothes for three hours to see if more melanin means less nicotine uptake and longer retention.

How Is the Trial Designed?

Group I: Low melanin Experimental Treatment 1 Intervention

Individuals with skin reflectance scores below 150 using the Mexameter 18 instrument.

Group II: High melanin Experimental Treatment 1 Intervention

Individuals with skin reflectance scores above 249 using the Mexameter 18 instrument

Who Is Running the Clinical Trial?

University of California, San Francisco

Lead Sponsor

Trials

2,636

Recruited

19,080,000+

Citations

1. mayoclinic.org mayoclinic.org/diseases-conditions/nicotine-dependence/expert-answers/third-hand-smoke/faq-20057791

What is thirdhand smoke, and why is it a concern? These can include cancer, heart disease and respiratory illness. The effects from long-term exposure to the toxins in thirdhand smoke are not ...

2. cdc.gov cdc.gov/tobacco/secondhand-smoke/health.html

Health Problems Caused by Secondhand Smoke Exposure to secondhand smoke has immediate harmful effects on the heart and blood vessels and can cause coronary heart disease and stroke.

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5501723/

Thirdhand Smoke: New Evidence, Challenges, and Future ... The long-term goals of the California Consortium on Thirdhand Smoke are to identify the health effects of exposure to THS, develop environmental indicators and ...

4. publichealthtoxicology.com publichealthtoxicology.com/Thirdhand-smoke-composition-and-consequences-A-narrative-review,151102,0,2.html

Thirdhand smoke composition and consequences The higher respiratory rate, presence of immature respiratory capacity and immune systems, and lower metabolic capacity are other factors ...

5. yalemedicine.org yalemedicine.org/news/what-is-thirdhand-smoke

What Is Thirdhand Smoke? Long-term exposure to thirdhand smoke pollutants has been shown to damage human cells and DNA and may be associated with asthma and cancer.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3784302/

Beliefs About the Health Effects of “Thirdhand” Smoke and ... There is no safe level of exposure to tobacco smoke. Thirdhand smoke is residual tobacco smoke contamination that remains after the cigarette is extinguished.