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

University of Aarhus

Status: Completed

Conditions: Symptoms and Signs; Inflammatory Response

Treatments: Other: Candle C; Other: Candle 1

Study type: Interventional

Funder types: Other

Identifiers

NCT04864600

201100

Details and patient eligibility

About

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.

Full 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.

Enrollment: 17 patients

Sex: All

Ages: 18 to 25 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Quadruple Blind

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17 participants in 3 patient groups

Standard Stearin Candle

Active Comparator group

Description:

Several candles will be lit. We will be using realistic burning cycles i.e. burning candles which extinguish and new ones being lit.

Treatment:

Other: Candle 1

Modified low emission candle

Experimental group

Description:

Several candles will be lit. We will be using realistic burning cycles i.e. burning candles which extinguish and new ones being lit.

Treatment:

Other: Candle C

Clean Air

No Intervention group

Description:

No candles in the chamber.