CANDLE - A Study of Acute Health Effects of Exposure to Particles Generated by Candles

Inflammatory Response Clinical Trial

Official title:

CANDLE - A Study of Acute Health Effects of Exposure to Particles Generated by Candles

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04864600
• Other study ID #: 201100
• Status: Completed
• Phase: N/A
• Start date: September 1, 2020
• Est. completion date: December 31, 2020

Study information

• Verified date: April 2021
• Source: University of Aarhus
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 17
• Est. completion date: December 31, 2020
• Est. primary completion date: December 31, 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 25 Years

Eligibility

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

Related Conditions & MeSH terms

• Inflammatory Response
• Symptoms and Signs

Intervention

Other:
• Candle C
Burning candles will produce particulate air pollution being passed on an exposure chamber where the participants will be sitting for 5 hours.
• Candle 1
Burning candles will produce particulate air pollution being passed on an exposure chamber where the participants will be sitting for 5 hours.

Locations

Country	Name	City	State
Denmark	Climate Chambers, Dept. Public Health, Aarhus University	Aarhus	Central Region Denmark

Sponsors (10)

Lead Sponsor	Collaborator
University of Aarhus	ASP-HOLMBLAD A/S, COOP Denmark, Danish Technological Institute, Danwax, European Candle Association, Liljeholmens Stearinfabrik, Lund University, Promol, University of Copenhagen

Country where clinical trial is conducted

Denmark, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Particles in Exhaled Air (Surfactant Protein A & Albumin)	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	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in Lung Function (FEV1 & FVC)	Spirometry	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in Fractional exhaled nitric oxide (FENO)	NIOX VERO system; Aerocrine AB, Sweden	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in white blood cells in Blood	White blood cells	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in Endothelial Progenitor Cells (EPCs) in Blood	Endothelial progenitor cells (EPC) further divided into early and late EPCs	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in inflammatory markers in Blood	Interleukin 8, interleukin 1	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in biomarkers in Blood	Metabolomics	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in nasal volume (using Acoustic rhinometry)	Acoustic rhinometry is used to assess the nasal cross sectional area and volume. The left and right nasal cavity were studied alternatively until three reproducible measurements were obtained. The minimum cross sectional cavity area is calculated from the means of the measurements. By integration of the area-distance curve, the sum of the volume 2 to 4 (vol2-4) from the nostril is determined on both sides.	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in biomarkers in Saliva Sample	An oral svap from Salivette was placed in the mouth of the participant to collect saliva by gently chewing the swab for one minute. Afterwards the saturated swab was removed to the suspended insert and closed firmly with a lid. Then the sample was transferred to a freezer and stored for -80 C until further analysis. The sample will be analyzed for biomarkers (amylase, cortisol, substance P, lysozyme and secretory IgA. (same unit measure))	after exposure (5 hours), and the day after exposure (24 hours)
Secondary	ReCIVA	Sampling of VOCs and particles in exhaled air. Breathing through a mask for 10-15 minutes makes it possible to collect VOCs and particles into tenax air sampling tubes.	At baseline (0 hour), after exposure (5 hours), and the day after exposure (24 hours)
Secondary	Change in Subjective Symptoms	n the exposure chamber participants are asked to fill out a symptom questionnaire every 30 minute regarding their well-being and experienced symptoms in eyes, nose and throat. The participants are asked to score their evaluation / rate the strength of symptoms on a Linear Numeric Scale from 0-10, with 10 being worst. Health effects are evaluated in relation to rated changes in symptoms	Every 30 minute during 5 hours of exposure
Secondary	Heart rate using a Fitbit	Using a Fitbit watch participants' heart rate is measured.	From exposure start until the morning after exposure (in total 24 hours)
Secondary	Sleep quality using a Fitbit	Using a Fitbit watch participants' sleep quality is measured.	during 48 hours