Table 1.

Characteristics of indoor allergen sampling devices

Method	Recommendations and considerations	Pros	Cons
Reservoir dust
Vacuum sampling	•Recommended for assessment of chronic exposure to all of the indoor allergens •Less representative of airway exposure compared to airborne dust •Better measure of chronic than acute exposure	•Easy to deploy •Lay people can be trained to collect own samples. •Samples can be collected from multiple surfaces. •Low costa	•Collection techniques may be variable, resulting in variability in samples collected. •Temporal scale of exposure imprecise
Settling dust	•Recommended for assessment of chronic exposure to all of the indoor allergens •Less representative of airway exposure compared to airborne dust	•Easy to deploy •Lay people can be trained to collect own samples. •Suitable for large-scale studies •Low costa	•Samplers must be left out for several days to weeks.
Airborne dust
Area volumetric air sampling	• Recommended for assessment of acute or chronic exposure to furry animal allergens •Better for furry animal allergens than cockroach and dust mite allergens, which tend to be on larger particles, so are more difficult to measure in air samples •Better representation airway exposure than reservoir dust •Can select for particle sizes that penetrate the respiratory tract	• Allows for particle size selection • Standardized equipment and methods allow for cross-study comparisons.	• Need for equipment calibration •Requires trained staff •Moderate to high costa
Furnace filter	•Recommended for assessment of chronic exposure to furry animal allergens •Better for furry animal allergens than cockroach and dust mite •Possible representation of breathable air in home during time period when filter was in place	•No extra equipment needed if home has central HVAC system •Lay people can be trained to collect own samples •Low costa	•Filters and HVAC systems vary across homes. •Some homes do not have central HVAC systems. •Vacuuming of filter may not collect representative dust sample from filter.
Ionic sampling	•May be useful for assessment of acute or chronic exposure to indoor allergens •Better collection of larger particles than smaller particles •Potentially better representation of airway exposure than reservoir dust	•Lay people can be trained to collect own samples. •More sensitive than volumetric sampling •Quieter operation than volumetric samplers •More efficient particle collection than volumetric samplers •Moderate to high costa	•Allergen concentrations measured much lower than when measured by volumetric sampling •Less efficient collection of smaller than larger particles
Personal samplers
Intra-nasal samplers	•Recommended for assessment of short-term (hours) acute exposure to allergens •Can be used for all allergens, but better for smaller particles •Better representation of airway exposure than reservoir dust sampling •Potentially better representation of acute airway exposure than other airborne dust sampling methods	•Easy to use •Captures particles entering the airway •Moderate costa	•May be cumbersome to use for longer than minutes-hours •Best when individual only breathes nasally since it does not capture exposure via mouth breathing •Assays for allergen quantification more cumbersome than assays for other sampling methods
Personal volumetric air samplers	• Recommended for assessment of acute exposure to furry animal allergens •Better representation of airway exposure than reservoir dust sampling •Better representation of personal exposure than stationary volumetric sampling since it moves with the individual •Short-term measurement could be used as surrogate for chronic exposure.	• Can estimate hourly, daily personal exposure •Allows for particle size selection •Standardized equipment and methods allow for cross-study comparisons.	• Devices are noisy and cumbersome to wear. •Need for equipment calibration •Requires trained staff •Moderate to high costa

^aEstimated cost for device only: low cost $5–100; moderate cost $100–300; high cost $300–1000