Pollen and air quality control in the Environmental Exposure Unit (EEU): A review of 20 years data for refinements, improvements, and distinction in indoor air quality assurance.
Sunday, March 4, 2018
South Hall A2 (Convention Center)
David Miller, PhD, Terry Walker, BA, Anne K. Ellis, MD FRCPC FAAAAI
RATIONALE: A variety of contaminants present in indoor and outdoor air can affect the clinical allergic response to airborne pollen. These include fine particles(PM2.5) and ground level ozone, fibres, volatile organic compounds(VOCs), mould and endotoxin. CO2concentrations above 1000 ppm are associated with significant negative cognitive effects. For the last 20 years, a systematic effort has been made to understand and limit the presence of contaminants and confounders of symptom perception in the EEU known to affect clinical responses to inhaled pollen during controlled allergen challenge.

METHODS: We have extensively analyzed the biotic and abiotic contaminants evaluated from inlet air, pollens, volatiles introduced by the building and participants in EEU studies over the past 20yrs of operations. We qualitatively analyzed changes and improvements over the EEU’s lifespan.

RESULTS: Data from the early 1990s revealed the original HVAC system and cleaning products used introduced undesirable abiotic contaminants. Third party analysis of commercially obtained pollen showed contamination with a variety of fungi and gram-negative bacteria depending on conditions of their production. Refinements to the EEU and feedback to pollen suppliers(and exclusion of batches not meeting standards) has led to remarkable improvement in all aspects of EEU quality control, with current analyses showing very low levels of fine particles, VOCs, moulds and endotoxin.

CONCLUSIONS: A sustained effort is needed to ensure that the exposure for any participant in a study using a Controlled Allergen Challenge facility is limited to only the relevant pollen allergen. The EEU has shown a high degree of success in maintaining this standard.