Cardiovascular Effects of Aerosols in Residences Study (CLEAR)
|ClinicalTrials.gov Identifier: NCT01570062|
Recruitment Status : Completed
First Posted : April 4, 2012
Last Update Posted : April 14, 2014
This study is focused on the effects of HEPA filtration to reduce exposures to combustion-derived air pollution (CDAP). Specifically, the study will evaluate the health benefits of HEPA filters and compare the cardiovascular toxicity of two major sources of CDAP, specifically traffic and residential wood combustion.
Specifically, the purpose of this study is to evaluate the ability of portable high efficiency particle air (HEPA) filters to reduce exposures to PM2.5 and air pollution indoors and to improve subclinical indicators of microvascular function and systemic inflammation among healthy adult participants.
The investigators hypothesize that HEPA filter use will help decrease indoor concentrations of CDAP thereby helping to mitigate the associated cardiovascular risks.
|Condition or disease||Intervention/treatment||Phase|
|Endothelial Dysfunction Systemic Inflammation||Device: HEPA Filter Device: HEPA Filtration Placebo||Phase 2|
To address knowledge gaps about health risks of specific pollution sources and to provide new evidence on the health benefits of air pollution interventions, the objectives of this study are: 1) quantify the relationship between low-level exposures to combustion-derived PM air pollution and subclinical indicators of cardiovascular disease risk; and 2) compare the relative impact of HEPA filtration for two major PM sources (traffic and residential wood combustion) on these indicators.
The use of HEPA filters may help to mitigate cardiovascular risks factors caused by combustion-derived air pollution (CDAP), (specifically woodstove and traffic emissions). We hypothesize that HEPA filter use and improved woodstove technology will help decrease indoor occurrences of CDAP. This project will help address knowledge gaps in CDAP-related health risks and benefits of interventions. Specific objectives include establishing a relationship between exposure to CDAP and biomarkers of cardiovascular risk and evaluating the impact of HEPA filter use towards improved indoor air quality and health indicators.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||83 participants|
|Intervention Model:||Crossover Assignment|
|Official Title:||Subclinical Cardiovascular Health Benefits of Interventions to Reduce Exposure to Combustion-Derived Particulate Air Pollution|
|Study Start Date :||November 2011|
|Actual Primary Completion Date :||August 2012|
|Actual Study Completion Date :||August 2012|
Active Comparator: Indoor Air HEPA Filtration
HEPA filters will be placed in participant's main living area and bedroom. Actual filtration will occur during only one of the two 7-day sampling periods.
Device: HEPA Filter
Two HEPA filters will be placed in participant's homes (one in the bedroom and one in the main living area); each HEPA will run for 2 consecutive 7-day sampling sessions. During one of the 7-day sampling sessions, the HEPA filter will run without the internal filter in place (i.e., "placebo" filtration).
Placebo Comparator: HEPA Filtration Placebo
For one of two 7-day sampling sessions, HEPA filters placed in participants' homes will be run without an actual filter in the housing unit.
Device: HEPA Filtration Placebo
for one of the two 7-day sampling sessions, both HEPA filters placed in participants' homes will be run without the actual filter in the housing unit.
- Difference in reactive hyperemia measurement after HEPA filtration [ Time Frame: after 1 week of filtration ]Participants endothelial function are tested after 1 week of HEPA filtration and after 1 week of non-HEPA filtration (placebo filtration).
- Difference in C-Reactive Protein after HEPA Filtration [ Time Frame: after 1 week of filtration ]Participants CRP is measured after 1 week of HEPA filtration and after 1 week of non-HEPA filtration (placebo filtration).
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01570062
|Canada, British Columbia|
|Simon Fraser University|
|Burnaby, British Columbia, Canada, V5A 1S6|
|Principal Investigator:||Ryan Allen, PhD||Simon Fraser University, Canada|