Wood Smoke Exposure for Healthy Subjects

(MASKOFF Trial)

Overseen By Patrice Ratliffe

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of North Carolina, Chapel Hill

Must not be taking: Systemic steroids, Oral anticoagulants, ß-blockers, Antihistamines

Disqualifiers: Cardiovascular disease, Diabetes, Asthma, Cancer, others

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

Compensation: Varies

Number of Visits: 6

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to study how breathing in wood smoke affects heart health in young, healthy adults. Participants will alternate between exercise and rest while exposed to both clean air and wood smoke. Researchers will collect blood samples and assess heart and lung functions before and after each exposure. This trial suits healthy individuals aged 18-35 who can exercise lightly for about an hour without heart or lung issues. As an unphased trial, it offers participants the opportunity to contribute to important research on environmental health impacts.

Will I have to stop taking my current medications?

The trial requires that you stop taking certain medications, such as systemic steroids, oral anticoagulants, ß-blockers, prebiotics, probiotics, and antihistamines. Other medications will be reviewed on a case-by-case basis by the medical staff.

What prior data suggests that this exposure method is safe for healthy subjects?

Research shows that wood smoke can affect health. One study found that short exposure to wood smoke caused only minor effects, suggesting that short-term exposure might be relatively mild for healthy people. However, wood smoke can irritate the lungs, cause inflammation, and impact the immune system, increasing the risk of lung infections.

For those with existing breathing issues like asthma or COPD (chronic obstructive pulmonary disease), wood smoke can worsen symptoms. Since this trial involves young, healthy people, the risk might be lower.

Overall, while potential risks exist, research indicates that short-term exposure to wood smoke in healthy individuals has shown limited effects. This suggests it might be well-tolerated in a controlled setting like this study. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores how controlled exposure to wood smoke might impact health, which is different from the typical focus of avoiding or reducing air pollution exposure. Unlike traditional methods that emphasize air purification or minimizing exposure to pollutants, this study aims to understand the effects of brief, controlled exposure to wood smoke combined with exercise and rest. By alternating exposure to wood smoke and filtered air, scientists hope to uncover insights into how such environmental factors can affect respiratory and overall health, potentially leading to new guidelines or interventions.

What evidence suggests that exposure to wood smoke could affect cardiovascular health?

Research shows that breathing in wood smoke can irritate the lungs and cause swelling. Studies have found that wood smoke might raise the risk of lung infections and impact the immune system. This trial will involve participants in controlled exposure to wood smoke to assess its effects. Experiments exposing healthy individuals to wood smoke in a controlled setting have shown small effects related to cell damage and inflammation. Long-term inhalation of smoke from burning wood or other plant materials links to chronic lung diseases like asthma and chronic obstructive pulmonary disease (COPD). Overall, wood smoke connects to various negative health effects, especially on lung and breathing health. ^{2 4 6 7 8}

Who Is on the Research Team?

James Samet, PhD

Principal Investigator

Environmental Protection Agency (EPA)

Are You a Good Fit for This Trial?

This trial is for healthy adults aged 18-35 with a BMI of 19-30, normal lung and heart function, up-to-date COVID vaccinations, and the ability to do mild exercise. It's not for those on long-term steroids or blood thinners, with high blood pressure or diabetes, cardiovascular risks over 10%, recent surgeries, certain medication use, pregnancy/breastfeeding status, smokers (including recent history), non-English speakers who can't consent properly.

Inclusion Criteria

My lung function is at least 80% of the expected level for someone my age, gender, ethnicity, and height.

Oxygen saturation greater than 94% at the time of physical exam

My lung function, measured by FEV1, is within the normal range for my age, gender, ethnicity, and height.

Exclusion Criteria

Individuals with a cardiovascular disease risk score greater than 10% using the ACC/AHA ASCVD risk calculator

I have had a respiratory illness in the last 6 weeks.

I am currently on long-term steroids or blood thinners.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Consenting

Participants undergo consenting process, medical review, and initial tests including spirometry and blood sampling

1 day

1 visit (in-person)

Exposure

Participants are exposed to filtered air and wood smoke on separate days with exercise and rest periods, followed by various tests

2 days

2 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after exposure, including tests and sample collection

2 days

2 visits (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Exposure to Wood Smoke

Trial Overview The MASKOFF study examines how wood smoke affects the heart and lungs in healthy young adults. Participants will breathe filtered air then wood smoke during two separate sessions involving rest and exercise intervals while their blood samples are taken along with lung and heart measurements before and after exposure.

How Is the Trial Designed?

Group I: Controlled Exposure Experimental Treatment 2 Interventions

All subjects will be exposed to both air containing wood smoke and filtered air for 2 hours with alternating 15 minutes of exercise (cycle ergometer) and rest.

Who Is Running the Clinical Trial?

University of North Carolina, Chapel Hill

Lead Sponsor

Trials

1,588

Recruited

4,364,000+

Environmental Protection Agency (EPA)

Collaborator

Trials

40

Recruited

95,500+

Published Research Related to This Trial

In Sub-Saharan Africa, personal exposure levels to wood smoke pollutants, such as PM2.5 and carbon monoxide, significantly exceed World Health Organization guidelines, with females experiencing higher exposure than males.

Strong associations were found between wood smoke exposure and various health issues, including respiratory diseases, increased blood pressure, low birth weight, and even under-five mortality, highlighting the urgent need for interventions to reduce this exposure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Exposure to Wood Smoke and Associated Health Effects in Sub-Saharan Africa: A Systematic Review. Bede-Ojimadu, O., Orisakwe, OE.[2021]

Accurate assessment of environmental tobacco smoke (ETS) exposure is crucial for health risk assessments, requiring unbiased estimates of the exposure-effect relationship and the distribution of ETS levels in various environments, such as workplaces and homes.

Key factors influencing ETS exposure assessments include the strength of the ETS source, environmental conditions, duration of exposure, and the timing of exposure relative to health outcomes, all of which must be considered to effectively estimate health risks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Occupational exposure to environmental tobacco smoke and health risk assessment. Jaakkola, MS., Samet, JM.[2018]

Epidemiological studies have explored the health effects of biomass smoke in various settings, highlighting the need for diverse study designs to accurately assess these impacts.

The Health Effects Workgroup emphasized the importance of using biomarkers and robust study designs to evaluate health outcomes in communities exposed to wood smoke from sources like wildfires and residential burning.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Biomass smoke exposures: health outcomes measures and study design. Noonan, CW., Balmes, JR.[2010]

Acute exposure to wood smoke in healthy young adults showed minimal overall impact on nasal inflammatory responses to a live attenuated influenza virus, with only IP-10 protein levels being suppressed after exposure.

However, the study revealed significant sex-specific differences in inflammatory responses, indicating that males and females react differently to wood smoke exposure and subsequent viral inoculation, which suggests the need for further research on how pollutants affect health based on sex.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Wood Smoke Exposure Alters Human Inflammatory Responses to Viral Infection in a Sex-Specific Manner. A Randomized, Placebo-controlled Study. Rebuli, ME., Speen, AM., Martin, EM., et al.[2020]

A study of 24,791 nonsmokers aged 12 and older found that exposure to secondhand smoke (SHS) at home resulted in significantly higher serum cotinine levels (0.522 ng/mL) compared to exposure at work (0.055 ng/mL), indicating that home environments pose a greater risk for SHS exposure.

The findings suggest a need for stronger public health initiatives to reduce SHS exposure at home, as it is associated with adverse health effects, particularly for nonsmokers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Exposure to second hand smoke at home and work among nonsmokers. Jain, RB.[2022]

No level of exposure to secondhand smoke (SHS) is safe, as it can lead to serious health issues like heart disease and lung cancer in adults, and increased risks of sudden infant death syndrome and respiratory problems in children.

From 1988-1994 to 1999-2004, self-reported SHS exposure at home and serum cotinine levels in the U.S. population significantly declined by 51.2% and 44.7%, respectively, but the reduction was less pronounced in children aged 4-19, highlighting the need for ongoing efforts to protect this vulnerable group.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Disparities in secondhand smoke exposure--United States, 1988-1994 and 1999-2004. [2022]

Increased use of woodburning for heating in North America has led to greater public exposure to harmful woodsmoke pollutants, raising concerns about health risks, especially for children.

The review highlights a significant gap in research on the toxicological effects of woodsmoke exposure, emphasizing the need for more studies to understand its impact on health and to inform regulatory standards.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The toxicology of inhaled woodsmoke. Zelikoff, JT., Chen, LC., Cohen, MD., et al.[2022]

Woodsmoke contains harmful pollutants, including carcinogenic compounds like carbon monoxide (CO) and nitrogen oxides (NOx), which pose significant health risks similar to those from other combustion sources, as established by extensive research.

The review questions whether woodsmoke should be regulated separately due to its unique properties and health impacts, suggesting that further research is needed to fully understand its risks compared to other ambient particles.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Woodsmoke health effects: a review. Naeher, LP., Brauer, M., Lipsett, M., et al.[2022]

About 37% of parents in rural Appalachian communities reported having at least one smoker in the household, but 50% of children aged 7-9 had detectable levels of cotinine in their serum, indicating significant secondhand smoke exposure.

The study found that 36.6% of children in Appalachian counties were exposed to secondhand smoke, which is much higher than the national average of 7.6%, highlighting the need for targeted interventions to reduce tobacco exposure in these communities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Serum Cotinine versus Parent Reported Measures of Secondhand Smoke Exposure in Rural Appalachian Children. Yeramaneni, S., Yolton, K., Kannan, K., et al.[2022]

In a 24-week study involving 150 adult smokers, switching to tobacco-heating cigarettes, snus, or ultra-low yield tobacco-burning cigarettes resulted in reduced exposure to harmful substances compared to traditional cigarette smoking.

The study highlights the differences in tobacco exposure among various products, contributing to the understanding of a risk continuum in tobacco use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Switching from usual brand cigarettes to a tobacco-heating cigarette or snus: Part 2. Biomarkers of exposure. Ogden, MW., Marano, KM., Jones, BA., et al.[2019]

Citations

1. epa.gov epa.gov/burnwise/wood-smoke-and-your-health

Wood Smoke and Your Health Wood smoke can irritate your lungs, cause inflammation, affect your immune system, and make you more prone to lung infections.

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6467301/

Wood Smoke Exposure Alters Human Inflammatory ... Epidemiologic and controlled exposure studies suggest that wood smoke and biomass exposure may contribute to increased risk of infection and reduced lung ...

3. cdc.gov cdc.gov/air-quality/media/MTbiomass_conference_health_outcomes_1.pdf

Biomass smoke exposures: Health outcomes measures ... Outcomes evaluated in studies of biomass smoke health effects in developing countries include acute lower respira- tory infection in children and chronic ...

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3369202/

Controlled human wood smoke exposure: oxidative stress ... A controlled exposure study of wood smoke particles in healthy humans showed minor effects related to oxidative stress and inflammation, including increased ...

5. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1043466620301058

Smoke exposure from chronic biomass burning induces ... Long-term exposure to biomass-burning smoke (BS) is associated with chronic obstructive pulmonary disease (COPD), asthma, and other chronic inflammatory lung ...

6. pubs.acs.org pubs.acs.org/doi/10.1021/acs.chemrestox.8b00318

Wood and Biomass Smoke: Addressing Human Health Risks ... Exposure to wood/biomass smoke PM (WBSPM) can exacerbate pre-existing respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD)

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3921260/

Systemic Effects of Wood Smoke in a Short-Term ... This experimental exposure study confirmed that only limited effects could be observed after a 3-hour wood smoke exposure in the 2 to 400 μg/m3 fine particle ...

8. who.int who.int/news-room/fact-sheets/detail/household-air-pollution-and-health

Household air pollution Household air pollution exposure leads to noncommunicable diseases including stroke, ischaemic heart disease, chronic obstructive pulmonary ...