CANDLE - A Study of Acute Health Effects of Exposure to Particles Generated by Candles
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Aarhus
- Enrollment
- 17
- Locations
- 1
- Primary Endpoint
- Change in Particles in Exhaled Air (Surfactant Protein A & Albumin)
Study Overview
Brief Summary
INTRODUCTION: Particle contamination is suggested to have substantial negative effects on health, with candles emitting huge amount of particles, thus being one of the largest contributors to indoor air pollution. Chronic low levels of exposure to indoor particles over time is an important risk factor for the health of the population as a whole and it becomes particularly important for vulnerable groups like people suffering from respiratory diseases such as asthma.
AIM: In a randomized controlled cross-over trial the difference in health effects between two candles I) a standard candle and II) a low emission candle modified from the standard candle is studied.
Detailed Description
INTRODUCTION; Particle contamination is suggested to have substantial negative effects on health, with candles emitting the huge amount of particles, thus being one of the largest contributors to indoor air pollution. Chronic low levels of exposure to indoor particles over time is an important risk factor for the health of the population as a whole and it becomes particularly important for vulnerable groups like children and the elderly or people already suffering from allergies and respiratory diseases such as asthma.
AIM: To study the difference in health effects between two candles I) a standard candle and II) a low emission candle modified from the standard candle. The following hypothesis will be examined: Short-term exposure to particles generated by the standard candle is associated with more objectively measurable effects in metabolomics inflammation compared to exposure to modified low-emission candle particles.
METHODS: Separated by two weeks 20 young asthmatics will be exposed in a randomized cross-over double-blind study under controlled conditions in a climate chamber to three different exposures; A) a standard (Scandinavian) stearin candle, B) a modified low emitting version of the same candle, and C) clean air from the adjacent chamber. The experiment will be carried out in groups of 3-6 participants.
MEASUREMENTS: TSI P-TRAK Ultrafine Particle Counter and SMPS will be used for particle counts. Health effects, including spirometry and fraction of exhaled nitric oxide (FeNO) will be evaluated in relation to local and systemic effects prior to, right after and 24 h. after exposure.
ANALYSIS: Mixed methods approach taking both time and exposure into account.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Prevention
- Masking
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Eligibility Criteria
- Ages
- 18 Years to 25 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Age 18-25
- •Medically treated / physician diagnosed mild seasonal asthma GINA guidelines step 1 or 2 (https://ginasthma.org/)
- •Never smoker or ex-smoker ≥ 6 months
- •Allergy > 1 common allergy
Exclusion Criteria
- •Any other disease that could influence the study parameters
- •Conditions that prevent safe access to the climate chambers (such as claustrophobia)
- •Perennial asthma
- •Need for continuous medical treatment for asthma
- •Pregnancy
Arms & Interventions
Standard Stearin Candle
Several candles will be lit. We will be using realistic burning cycles i.e. burning candles which extinguish and new ones being lit.
Intervention: Candle 1 (Other)
Modified low emission candle
Several candles will be lit. We will be using realistic burning cycles i.e. burning candles which extinguish and new ones being lit.
Intervention: Candle C (Other)
Clean Air
No candles in the chamber.
Outcomes
Primary Outcomes
Change in Particles in Exhaled Air (Surfactant Protein A & Albumin)
Time Frame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
PExA: Subjects performed repeated breath maneuvers allowing for airway closure and re-opening, and exhaled particles were optically counted and collected on a membrane using the PExA® instrument set-up
Secondary Outcomes
- Heart rate using a Fitbit(From exposure start until the morning after exposure (in total 24 hours))
- Change in Lung Function (FEV1 & FVC)(At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours))
- Change in Fractional exhaled nitric oxide (FENO)(At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours))
- Change in white blood cells in Blood(At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours))
- Change in Endothelial Progenitor Cells (EPCs) in Blood(At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours))
- Change in inflammatory markers in Blood(At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours))
- Change in biomarkers in Blood(At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours))
- Change in nasal volume (using Acoustic rhinometry)(At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours))
- Change in biomarkers in Saliva Sample(after exposure (5 hours), and the day after exposure (24 hours))
- ReCIVA(At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours))
- Change in Subjective Symptoms(Every 30 minute during 5 hours of exposure)
- Sleep quality using a Fitbit(during 48 hours)
Investigators
Torben Sigsgaard
Professor and medical doctor
University of Aarhus