Clinical trial NCT04864600: CANDLE - A Study of Acute Health Effects of Exposure to Particles Generated by Candles
Official title: CANDLE - A Study of Acute Health Effects of Exposure to Particles Generated by Candles
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Inflammatory Response
Symptoms and Signs
Keywords: Stearin candle
Health effects
Inflammation
Asthmatics
Particle contamination
Indoor air
Pollutant
Lead sponsor: University of Aarhus
Sponsor class: OTHER
Collaborators: name: Lund University
name: University of Copenhagen
name: Danish Technological Institute
name: ASP-HOLMBLAD A/S
name: COOP Denmark
name: Danwax
name: Liljeholmens Stearinfabrik
name: Promol
name: European Candle Association
First posted: 2021-04-29
Enrollment: 17
Sex: ALL
Minimum age (years): 18
Maximum age (years): 25
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: A randomized cross-over double-blind study under controlled conditions in a climate chamber having three different exposures; A) a standard (Scandinavian) stearin candle, B) a modified low emitting version of the same candle, and C) clean air
Primary purpose: PREVENTION

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.

Eligibility criteria: 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

Primary outcomes:
measure: Change in Particles in Exhaled Air (Surfactant Protein A & Albumin)
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary outcomes:
measure: Change in Lung Function (FEV1 & FVC)
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
measure: Change in Fractional exhaled nitric oxide (FENO)
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
measure: Change in white blood cells in Blood
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
measure: Change in Endothelial Progenitor Cells (EPCs) in Blood
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
measure: Change in inflammatory markers in Blood
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
measure: Change in biomarkers in Blood
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
measure: Change in nasal volume (using Acoustic rhinometry)
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
measure: Change in biomarkers in Saliva Sample
timeFrame: after exposure (5 hours), and the day after exposure (24 hours)
measure: ReCIVA
timeFrame: At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
measure: Change in Subjective Symptoms
timeFrame: Every 30 minute during 5 hours of exposure
measure: Heart rate using a Fitbit
timeFrame: From exposure start until the morning after exposure (in total 24 hours)
measure: Sleep quality using a Fitbit
timeFrame: during 48 hours
Other outcomes:
Locations:
city: Aarhus
country: Denmark
facility: Climate Chambers, Dept. Public Health, Aarhus University
state: Central Region Denmark
Study officials:
affiliation: University of Aarhus
name: Torben Sigsgaard, Prof.
role: PRINCIPAL_INVESTIGATOR
References: