Pollution; ExposureTHS04NCT04013256
Controlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke
A study testing Cigarette Smoke in people with Pollution; Exposure and Smoke Inhalation, run by University of California, San Francisco at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Pollution; Exposure, Smoke Inhalation, Exposure to Pollution
- What is being tested?
- Cigarette Smoke
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 66 participants
- Where
- 1 siteUnited States
- Study dates
- 20 Jan 2020to 31 Oct 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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.
Who cannot join
- 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 locations and contacts
1 site in 1 country.
United States1 site
Zuckerberg San Francisco General Hospital
San Francisco, California, 94110
About this study
Official title: Controlled Human Exposure and THS Generation Core
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.
Read the 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
- Being tested
- Cigarette Smoke, Clean Air and Clean Clothing/Sham exposure
- Medical subject headings
- Smoke Inhalation Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cigarette SmokeOther
Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.
Clean Air and Clean Clothing/Sham exposureOther
Clean air, created by high-efficiency particulate air (HEPA) and charcoal filtration and temperature and humidity control.
Clean cotton clothing.
| Study group | Role | What they receive |
|---|---|---|
| Dermal Exposure to Thirdhand Cigarette Smoke | Experimental | Participants will wear clothing that has been exposed to cigarette smoke, for 3 hours while breathing filtered, temperature and humidity controlled air. Receives: Other: Cigarette Smoke |
| Inhalational Exposure to Thirdhand Cigarette Smoke | Active comparator | Participants will breathe cigarette smoke aerosol that has been aged for 22 hours, for 3 hours while wearing clean clothing. Receives: Other: Cigarette Smoke |
| Inhalational Exposure to Secondhand Cigarette Smoke | Active comparator | Participants will breathe cigarette smoke aerosol that has been aged for 30 minutes, for 3 hours while wearing clean clothing. Receives: Other: Cigarette Smoke |
| Clean Air Exposure | Sham comparator | Participants will breathe filtered, temperature and humidity controlled air while wearing clean clothing for 3 hours. Receives: Other: Clean Air and Clean Clothing/Sham exposure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in flow-mediated dilation (FMD) of the brachial artery, caused by pollution exposures, measured by ultrasound
High-resolution ultrasound of right brachial artery is performed 1 cm distal to antecubital fossa with a 10 megahertz (MHz) linear array probe coupled to a General Electric (GE) Vivid 7 Imaging System. To assess endothelium-dependent dilation, after recording baseline B-mode ultrasound images of the brachial artery and spectral Doppler images of flow velocity, a forearm cuff is inflated to 250 mmHg for 5 minutes to induce reactive hyperemia. Immediately after deflation, Doppler images are obtained to measure reactive hyperemia. FMD of brachial artery will be determined every 15 seconds between 30 and 120 seconds after cuff deflation to capture maximal dilation.The % FMD will be calculated as ratio between the maximum post cuff release brachial artery diameter and baseline diameter. By comparing changes in FMD before exposure, after exposure and next day, we will be able to assess effects of exposure on endothelial function and the potential recovery from these effects.
Measured: Baseline (before exposure) 30 minutes (after 30 minutes exposure) and 3 hours.
Secondary outcomes (1)
Changes in trans-epidermal water loss caused by pollution exposures, comparing intact skin to tape-stripped skin
We will measure trans-epidermal water loss (TEWL) on the volar forearm using a dermal relative humidity monitor (model IP52, Delfin Technologies Inc.) on adjacent circles of intact skin and skin that has been tape stripped prior to exposure. By comparing changes in TEWL at these two sites, before and after exposure and at day 2 and day 5, we will be able to detect any effects of dermal cigarette smoke exposure on skin barrier function and the rate of barrier function recovery.
Measured: Baseline, 30 minutes, 3 hours, 2 days, 5 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jul 2019
- Study start20 Jan 2020
- Primary completion31 Oct 2024 (estimated)
- Study completion31 Oct 2024 (estimated)
Why it stopped: The human exposure facility was closed by the University.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pollution; ExposureStudies of the same condition, open and under way.
- More trials run by University of California, San FranciscoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Crossover assignment
- Masking
- None (open label)
- Enrolment
- 66 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, San Francisco
- Sponsor type
- University, hospital or other
- Collaborators
- Tobacco Related Disease Research Program
- Responsible party
- Sponsor
- Investigators
- Suzaynn F Schick, PhD, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04013256
- Sponsor's protocol ID
- 28PT-0081
- Acronym
- THS04
- Status last verified
- Aug 2023
- First submitted
- 25 Jun 2019
- Last updated
- 28 Aug 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: We will share the individual participant data (IPD) that underlie the results in our publications.
Study at a glance
From the registry record, last updated by the sponsor on 28 Aug 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Controlled Human Exposure and THS Generation Core
- ClinicalTrials.gov ID
- NCT04013256
- Acronym / sponsor ID
- THS04 / 28PT-0081
- Conditions
- Pollution; Exposure, Smoke Inhalation, Exposure to Pollution
- Study type
- Interventional
- Recruitment status
- SuspendedReason stopped: The human exposure facility was closed by the University.
- Enrolment
- 66 participants (estimated)
- Lead sponsor
- University of California, San FranciscoUniversity, hospital or other
- Collaborators
- Tobacco Related Disease Research Program
- Study start
- 20 Jan 2020 (actual)
- Primary completion
- 31 Oct 2024 (estimated)
- Study completion
- 31 Oct 2024 (estimated)
- First posted
- 9 Jul 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 4
- Model description
- Crossover assignment
| Arm | Type | Receives |
|---|---|---|
| Dermal Exposure to Thirdhand Cigarette Smoke | Experimental | Other: Cigarette SmokeParticipants will wear clothing that has been exposed to cigarette smoke, for 3 hours while breathing filtered, temperature and humidity controlled air. |
| Inhalational Exposure to Thirdhand Cigarette Smoke | Active comparator | Other: Cigarette SmokeParticipants will breathe cigarette smoke aerosol that has been aged for 22 hours, for 3 hours while wearing clean clothing. |
| Inhalational Exposure to Secondhand Cigarette Smoke | Active comparator | Other: Cigarette SmokeParticipants will breathe cigarette smoke aerosol that has been aged for 30 minutes, for 3 hours while wearing clean clothing. |
| Clean Air Exposure | Sham comparator | Other: Clean Air and Clean Clothing/Sham exposureParticipants will breathe filtered, temperature and humidity controlled air while wearing clean clothing for 3 hours. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- 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.
Key exclusion criteria (2 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cigarette SmokeCigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke. | Other | Dermal Exposure to Thirdhand Cigarette Smoke, Inhalational Exposure to Secondhand Cigarette Smoke, Inhalational Exposure to Thirdhand Cigarette Smoke |
| Clean Air and Clean Clothing/Sham exposureClean air, created by high-efficiency particulate air (HEPA) and charcoal filtration and temperature and humidity control. Clean cotton clothing. | Other | Clean Air Exposure |
Primary outcome
Changes in flow-mediated dilation (FMD) of the brachial artery, caused by pollution exposures, measured by ultrasound
Time frame: Baseline (before exposure) 30 minutes (after 30 minutes exposure) and 3 hours.
High-resolution ultrasound of right brachial artery is performed 1 cm distal to antecubital fossa with a 10 megahertz (MHz) linear array probe coupled to a General Electric (GE) Vivid 7 Imaging System. To assess endothelium-dependent dilation, after recording baseline B-mode ultrasound images of the brachial artery and spectral Doppler images of flow velocity, a forearm cuff is inflated to 250 mmHg for 5 minutes to induce reactive hyperemia. Immediately after deflation, Doppler images are obtained to measure reactive hyperemia. FMD of brachial artery will be determined every 15 seconds between 30 and 120 seconds after cuff deflation to capture maximal dilation.The % FMD will be calculated as ratio between the maximum post cuff release brachial artery diameter and baseline diameter. By comparing changes in FMD before exposure, after exposure and next day, we will be able to assess effects of exposure on endothelial function and the potential recovery from these effects.
1 secondary outcome
Changes in trans-epidermal water loss caused by pollution exposures, comparing intact skin to tape-stripped skin
Time frame: Baseline, 30 minutes, 3 hours, 2 days, 5 days
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Aug 2023.
- Individual participant dataSharing planned: Yes. We will share the individual participant data (IPD) that underlie the results in our publications.
Related trials for Pollution; Exposure
Not yet recruiting
Reducing Exposure With Air Cleaners and Technology
Asthma, COPD (Chronic Obstructive Pulmonary Disease)
Recruiting
Ambient Air and Noise Effect on Cardiovascular Health Risk and Lifestyle Intervention to Attenuate It (METSGREEN)
Cardiovascular Diseases (CVD), Metabolic Syndrome
Recruiting
Lungs on Fire: Wildfire Smoke, Incident Diseases, Susceptible Populations, and Community Values in Canada
Asthma, Chronic Obstructive Pulmonary Disease (COPD)
Recruiting
Voices Illuminating Solutions for Outdoor Workers' Needs and Safety
Air Pollution Exposure
Active, not recruiting
Effect of an Antioxidant Dietary Supplement on Skin Radiance
Healthy Women
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Suzaynn F Schick, PhD principal investigator
University of California, San Francisco
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Cigarette Smoke in people with Pollution; Exposure and Smoke Inhalation, run by University of California, San Francisco at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: paused, as of the sponsor's last update on 28 Aug 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in flow-mediated dilation (FMD) of the brachial artery, caused by pollution exposures, measured by ultrasound (time frame: Baseline (before exposure) 30 minutes (after 30 minutes exposure) and 3 hours.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Aug 2023.