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Updated: Mar 21, 2026
Symptom Assessment of Patients with Allergic Rhinitis Using an Allergen Exposure Chamber
Published on: March 3, 2023
Time-Based Measurement of Personal Mite Allergen Bioaerosol Exposure over 24 Hour Periods
Euan R Tovey1, Damien Liu-Brennan1, Frances L Garden1,2,3
1Woolcock Institute of Medical Research, The University of Sydney, Glebe, New South Wales, Australia.
Abstract:
Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for future technical development and clinical applications.
Insights
New methods reveal house dust mite allergen exposure patterns. Contrary to popular belief, beds are not the primary source of exposure for most individuals, with indoor domestic locations showing higher concentrations.
Area of Science:
- Environmental Health
- Allergology
- Bioaerosol Science
Background:
- Allergic diseases like asthma and rhinitis are prevalent globally.
- House dust mites are a major source of allergens triggering allergic symptoms.
- Previous research lacked methods to accurately measure personal exposure to mite allergens over time.
Purpose of the Study:
- To develop and validate novel methods for assessing personal exposure to mite allergen bioaerosols.
- To investigate the time-geography of house dust mite allergen exposure in adults.
- To identify the primary locations contributing to daily mite allergen exposure.
Main Methods:
- Development of a miniature, time-based air sampler placed in the participant's breathing zone.
- Utilizing time-lapse cameras to correlate air sampling with participant location.
- Analysis of collected airborne particles for Der p 1 mite allergen using amplified ELISA after post-hoc subsampling based on location and time.
Main Results:
- Mite allergen Der p 1 was detected in 57.2% of collected subsamples.
- Exposure patterns varied significantly over 24-hour periods.
- Indoor domestic locations, particularly during the day and evening, showed higher allergen concentrations.
- In-bed exposure during sleep accounted for only 9.85% of total exposure, significantly less than other indoor domestic settings.
Conclusions:
- Novel methods enable detailed assessment of personal bioaerosol exposure patterns.
- Beds are not the predominant site for house dust mite allergen exposure.
- Findings highlight the importance of indoor domestic environments in overall mite allergen exposure and suggest new avenues for research and clinical intervention.
