Wood Smoke Exposure for Healthy Subjects
(MASKOFF Trial)
Recruiting in Palo Alto (17 mi)
Age: 18 - 65
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
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
Trial Summary
What is the purpose of this trial?MASKOFF Clinical Trials 8/22/23
Brief Summary:
Purpose: The study is designed to investigate cardiovascular effects of young healthy human subjects exposed to wood smoke.
Participants: Approximately 80 young (18-35 years old) healthy subjects to complete.
Procedure (methods): After consenting to participate in the study, subjects will be exposed first to filtered air and on the next exposure day to approximately 500 µg/m\^3 wood smoke. Both exposures will be 2 hours long with alternating 15 min of exercise (cycle ergometer) and 15 min rest period. The exercise level will be adjusted to achieve approximately 20 L/min/m\^2 minute ventilation. Venous blood samples and measurements of lung, cardiac and vascular function will be made prior to and immediately following each exposure. Induced sputum samples and nasal epithelial lining fluid will be collected approximately 24 hours post each exposure.
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.
Is wood smoke exposure safe for humans?
Research indicates that exposure to wood smoke can be harmful to human health, as it is associated with various adverse effects, including respiratory infections and immune system impacts. It contains pollutants that are known to be harmful, and more studies are needed to fully understand the risks.
12345How does the treatment 'Exposure to Wood Smoke' differ from other treatments for this condition?
The 'Exposure to Wood Smoke' treatment is unique because it involves intentionally exposing healthy subjects to wood smoke, which is not a standard treatment for any condition. This approach is novel as it aims to study the effects of wood smoke exposure, unlike other treatments that typically focus on reducing or eliminating exposure to harmful smoke.
678910Eligibility Criteria
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.
+9 more
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.
+18 more
Trial Timeline
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)
Participant Groups
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.
2Treatment groups
Experimental Treatment
Placebo Group
Group I: Wood SmokeExperimental Treatment1 Intervention
Subjects will be exposed to air containing wood smoke for 2 hours with alternating 15 minutes of exercise (cycle ergometer) and rest.
Group II: Filtered airPlacebo Group1 Intervention
Subjects will be exposed once to filtered air for 2 hours with alternating 15 minutes of exercise (cycle ergometer) and rest.
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
U.S. Environmental Protection Agency Human Studies FacilityChapel Hill, NC
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Who Is Running the Clinical Trial?
University of North Carolina, Chapel HillLead Sponsor
Environmental Protection Agency (EPA)Collaborator
References
Exposure to Wood Smoke and Associated Health Effects in Sub-Saharan Africa: A Systematic Review. [2021]Observational studies suggest that exposure to wood smoke is associated with a variety of adverse health effects in humans.
The toxicology of inhaled woodsmoke. [2022]In addition to developing nations relying almost exclusively upon biomass fuels, such as wood for cooking and home heating, North Americans, particularly in Canada and the northwestern and northeastern sections of the United States, have increasingly turned to woodburning as an alternate method for domestic heating because of increasing energy costs. As a result, the number of households using woodburning devices has increased dramatically. This has resulted in an increase in public exposure to indoor and outdoor woodsmoke-associated pollutants, which has prompted widespread concern about the adverse human health consequences that may be associated with prolonged woodsmoke exposure. This mini-review article brings together many of the human and animal studies performed over the last three decades in an attempt to better define the toxicological impact of inhaled woodsmoke on exposed children and adults; particular attention is given to effects upon the immune system. General information regarding occurrence and woodsmoke chemistry is provided so as to set the stage for a better understanding of the toxicological impact. It can be concluded from this review that exposure to woodsmoke, particularly for children, represents a potential health hazard. However, despite its widespread occurrence and apparent human health risks, relatively few studies have focused upon this particular area of research. More laboratory studies aimed at understanding the effects and underlying mechanisms of woodsmoke exposure, particularly on those individuals deemed to be at greatest risk, are badly needed, so that precise human health risks can be defined, appropriate regulatory standards can be set, and accurate decisions can be made concerning the use of current and new woodburning devices.
Biomass smoke exposures: health outcomes measures and study design. [2010]Epidemiological studies of biomass smoke health effects have been conducted in a variety of settings and with a variety of study designs. The Health Effects Workgroup discussed several approaches for the investigation of health effects in communities exposed to wood smoke from nearby wildland fires, intentional agricultural burning, or residential biomass burning devices such as woodstoves or cookstoves. This presentation briefly reviews observational and intervention studies that have been conducted within these exposure settings. The review is followed by a summary of discussion points among the workgroup members with particular emphasis on study design and the use of biomarkers for assessing outcomes in biomass smoke-exposed populations.
Woodsmoke health effects: a review. [2022]The sentiment that woodsmoke, being a natural substance, must be benign to humans is still sometimes heard. It is now well established, however, that wood-burning stoves and fireplaces as well as wildland and agricultural fires emit significant quantities of known health-damaging pollutants, including several carcinogenic compounds. Two of the principal gaseous pollutants in woodsmoke, CO and NOx, add to the atmospheric levels of these regulated gases emitted by other combustion sources. Health impacts of exposures to these gases and some of the other woodsmoke constituents (e.g., benzene) are well characterized in thousands of publications. As these gases are indistinguishable no matter where they come from, there is no urgent need to examine their particular health implications in woodsmoke. With this as the backdrop, this review approaches the issue of why woodsmoke may be a special case requiring separate health evaluation through two questions. The first question we address is whether woodsmoke should be regulated and/or managed separately, even though some of its separate constituents are already regulated in many jurisdictions. The second question we address is whether woodsmoke particles pose different levels of risk than other ambient particles of similar size. To address these two key questions, we examine several topics: the chemical and physical nature of woodsmoke; the exposures and epidemiology of smoke from wildland fires and agricultural burning, and related controlled human laboratory exposures to biomass smoke; the epidemiology of outdoor and indoor woodsmoke exposures from residential woodburning in developed countries; and the toxicology of woodsmoke, based on animal exposures and laboratory tests. In addition, a short summary of the exposures and health effects of biomass smoke in developing countries is provided as an additional line of evidence. In the concluding section, we return to the two key issues above to summarize (1) what is currently known about the health effects of inhaled woodsmoke at exposure levels experienced in developed countries, and (2) whether there exists sufficient reason to believe that woodsmoke particles are sufficiently different to warrant separate treatment from other regulated particles. In addition, we provide recommendations for additional woodsmoke research.
Wood Smoke Exposure Alters Human Inflammatory Responses to Viral Infection in a Sex-Specific Manner. A Randomized, Placebo-controlled Study. [2020]Exposure to particulates from burning biomass is an increasing global health issue. Burning biomass, including wood smoke, is associated with increased lower respiratory infections.
Serum Cotinine versus Parent Reported Measures of Secondhand Smoke Exposure in Rural Appalachian Children. [2022]Secondhand smoke (SHS) exposure in Appalachian children and associated adverse effects is understudied and not well documented. This study assessed the prevalence of SHS exposure in Appalachian children by parental self-report and internal biological measure.
Exposure to second hand smoke at home and work among nonsmokers. [2022]Exposure to second hand smoke (SHS) is associated with adverse health effects. This study was undertaken to assess comparative levels of exposure to SHS at home and work among nonsmokers aged ⩾12 years. Data from National Health Examination Survey for 1999-2010 were analyzed to estimate exposure to SHS. Total number of subjects included in the study was 24,791. Those who self-reported not having used any tobacco products during the last five days were considered nonsmokers for the purpose of this study. Serum cotinine levels were used as the outcome variable to indicate the level of exposure to SHS. Adjusted serum cotinine levels for those with no exposure to SHS, exposure to SHS at work only, exposure to SHS at home only, and exposure to SHS at home and work were 0.047 (0.044-0.050)n g/mL, 0.055 (0.047-0.064) ng/mL, 0.522 (0.401-0.678) ng/mL, and 0.485 (0.280-0.0840) ng/mL respectively. Public efforts to reduce exposure to SHS at home should be strengthened.
Occupational exposure to environmental tobacco smoke and health risk assessment. [2018]This article addresses concepts of environmental tobacco smoke (ETS) exposure assessment relevant for health risk assessment based on human studies. We present issues that should be considered when selecting a method for ETS exposure assessment for the purposes of health risk assessment and review data on ETS exposure levels in the workplace and in home environments. Two types of estimates are needed for a quantitative risk assessment of the health effects resulting from occupational ETS exposure: (italic)a(/italic)) an unbiased estimate of the exposure-effect (or dose-response) relation between ETS and the health effect of interest, and (italic)b(/italic)) estimates of the distribution of ETS exposure in different workplaces. By combining the estimated exposure-effect relation with information on exposure distribution for a population of interest, we can calculate the proportions of disease cases attributable to occupational ETS exposure as well as the excess number of cases due to specified exposure conditions. Several dimensions of the exposure profile should be considered when assessing ETS exposure for estimating the exposure-effect relation, including the magnitude of exposure and the biologically relevant time specificity of exposure. The magnitude of exposure is determined by the ETS source strength, environmental factors modifying concentrations, and duration of exposure. Time specificity considerations include the latency period for each health outcome of interest, the time-exposure profile relevant for different disease mechanisms, and the sensitive age period with regard to health effects. The most appropriate indicator of ETS exposure depends on these factors and on the time period that can be assessed with different methods.
Switching from usual brand cigarettes to a tobacco-heating cigarette or snus: Part 2. Biomarkers of exposure. [2019]A randomized, multi-center study of adult cigarette smokers switched to tobacco-heating cigarettes, snus or ultra-low machine yield tobacco-burning cigarettes (50/group) was conducted, and subjects' experience with the products was followed for 24 weeks. Differences in biomarkers of tobacco exposure between smokers and never smokers at baseline and among groups relative to each other and over time were assessed. Results indicated reduced exposure to many potentially harmful constituents found in cigarette smoke following product switching. Findings support differences in exposure from the use of various tobacco products and are relevant to the understanding of a risk continuum among tobacco products (ClinicalTrials.gov Identifier: NCT02061917).
Disparities in secondhand smoke exposure--United States, 1988-1994 and 1999-2004. [2022]No level of exposure to secondhand smoke (SHS) is safe. Breathing SHS can cause heart disease and lung cancer in nonsmoking adults and increases the risk for sudden infant death syndrome, acute respiratory infections, middle-ear disease, and exacerbation of asthma in children. In the United States, exposure to SHS declined approximately 70% from the late 1980s through 2002, most likely reflecting widespread implementation of laws and policies prohibiting smoking in indoor workplaces and public places during this period. Although the major sources of SHS exposure for nonsmoking adults are the home and workplace, the primary source of SHS exposure for children is the home; therefore, eliminating smoking in workplaces and public places is less likely to reduce children's exposure to SHS. This report examines changes in the prevalence of self-reported SHS exposure at home and changes in any exposure, as measured by serum cotinine (a biologic indicator of SHS exposure), in nonsmoking children, adolescents, and adults. The analysis was conducted using data from the 1988-1994 and 1999-2004 National Health and Nutrition Examination Surveys (NHANES). The results indicated that self-reported SHS exposure at home and SHS exposure as measured by serum cotinine declined significantly (i.e., by 51.2% and 44.7%, respectively) in the U.S. population from 1988-1994 to 1999-2004; however, the decline was smaller for persons aged 4-11 years and 12-19 years. These results underscore the need to continue surveillance of SHS exposure and to focus on strategies to reduce children's SHS exposure.