Recruiting

Observational Study

Sponsor:

UCLA

Code:

NCT06020248

Conditions

Healthy

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Interventions

Wear clothing that has been exposed to cigarette smoke for 3 hours.

Study Details

Brief summary:

This is a pilot study of the effects of dermal melanin on dermal uptake and retention of nicotine. The initial hypothesis is that higher levels of dermal melanin will correlate with lower uptake and longer retention of nicotine in the skin and body.

Conditions

Healthy

Study ID

NCT06020248

Start date

Sep 1, 2023

Status verified date

Jun, 2026

Completion date

Nov, 2026

Anticipated

Primary completion date

Nov, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Adult nonsmoker
  • Aged 18-50
  • Skin reflectance scores below 150 or above 249 using the Mexameter 18 instrument
  • Healthy on the basis of medical history
  • Systolic blood pressure <150
  • Diastolic blood pressure <100
  • C-reactive protein <3.1 mg/ml
  • Liver function (AST and ALT) in normal ranges
  • kidney function (BUN) in normal ranges
  • LDL<131
  • Blood glucose <110
  • Not exposed to tobacco SHS.

Exclusion Criteria:

  • Dermal skin reflectance score between 150 and 249, as measured by the Mexameter 18 instrument.
  • Positive SARS-CoV-2 antibody test
  • 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 greater than or equal to 150
  • Diastolic blood pressure greater than or equal to 100
  • Blood glucose greater than or equal to 110
  • LDL greater than or equal to130
  • Pregnancy or breastfeeding (by urine 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 OTC medicines
  • Occupational exposure to smoke, dusts OR fumes
  • Concurrent participation in another clinical trial
  • Unable to communicate in English
  • No social security number

Study Design

Enrollment

60 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Low melanin

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

experimental: High melanin

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

Interventions

Wear clothing that has been exposed to cigarette smoke for 3 hours.

Cotton clothing is exposed to smoke from Marlboro Red (hard pack) cigarettes at 1-1.2 mg/m3 repeatedly, until total exposure equals 3 grams total particulate material. When tested after exposure, the clothing typically contained 59.15 +/- 18 µg nicotine and 42 +/- 24 ng NNK per gram. The mass of the clothing varies by size, but the average combination of pants and shirt contains 32 mgs nicotine and 23 µg NNK.

Primary outcome measure

  • Change in blood concentrations of nicotine [ Time Frame: Baseline and 3 hours ]
  • Total combined urinary concentrations of the nicotine metabolites cotinine and 3-hydroxycotinine [ Time Frame: First void, collected for 10 days ]

Central Contacts and Locations

Central contacts

Suzaynn F Schick, PhD

415-514-3535suzaynn@gmail.com

Abel Huang, BS

(415) 514-9011abel.huang@ucsf.edu

Locations

Zuckerberg San Francisco General Hospital

Recruiting

San Francisco, California, United States, 94110

Contacts

Abel Huang

Abel.Huang@ucsf.edu

Principal Investigator:

Suzyann Schick, PhD

More Information

Sponsor

University of California, San Francisco

Last update posted

Jun 16, 2026

Last verified

Jun, 2026

Keywords

  • Thirdhand tobacco smoke
  • Dermal
  • Exposure
  • Tobacco Smoke Pollution
  • Melanin
  • Nicotine

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of California, San Francisco on 2026-06-16.