Effect of a novel temperature-controlled laminar airflow device on personal breathing zone aeroallergen exposure

Abstract

Temperature-controlled laminar airflow improves symptoms in atopic asthmatics, but its effects on personal allergen exposure are unknown. We aimed to evaluate its effects on personal cat allergen and particulate exposures in a simulated bedroom environment. Five healthy volunteers lay under an active and an inactive temperature-controlled laminar airflow device for 175 min, in a simulated bedroom containing bedding from a cat owner. Total airborne particles (≥0.5 - ≥10 μm diameter) were quantified with a laser particle counter. Airborne allergen was sampled with Institute of Occupational Medicine filters. Inhaled exposure was sampled with nasal air samplers. Allergen-containing particles were quantified by immunoassay. Treatment reduced total airborne particles (>0.5 μm diameter) by >99% (P < 0.001) and reduced airborne allergen concentration within the breathing zone (ratio of median counts = 30, P = 0.043). Treatment reduced inhaled allergen (ratio of median counts = 7, P = 0.043). Treatment was not associated with a change in airborne allergen concentration outside of the breathing zone (P = 0.160). Temperature-controlled laminar airflow treatment of individuals in an allergen-rich experimental environment results in significant reductions in breathing zone allergenic and non-allergenic particle exposure, and in inhaled cat allergen exposure. These findings may explain the clinical benefits of temperature-controlled laminar airflow.

A Comparison between Temperature-Controlled Laminar Airflow Device and a Room Air-Cleaner in Reducing Exposure to Particles While Asleep

“…The room air cleaner behaves as a displacement or centralized HVAC system, which has been shown as ineffective in delivering clean air into the BZ. With the TLA treatment, there were reductions of similar magnitude to study of [22]. As in [22] study our measurement showed a rapid decrease of large particles in the breathing zone almost immediately after each duvet movement.…”

“…With the TLA treatment, there were reductions of similar magnitude to study of [22]. As in [22] study our measurement showed a rapid decrease of large particles in the breathing zone almost immediately after each duvet movement. On the other hand, reduction of small particles was less efficient than for large particles.…”

“…Similar values of reduction rate in the rest of the measurement period means the TLA device reaches low concentration (99.9% of initial particles removed) within a short period of time and is able to protect the BZ from further transport of particles from peripheral zone. Similar results were observed by [22] comparing real-person exposure to small and large positioned in bed under two conditions: the TLA device operating and not operating.…”

“…Recently, a new environmental control method–temperature-controlled laminar air flow (TLA)–has been introduced [22]. This method is based on local downward laminar air delivery of cleaned, air-conditioned air of low speed from overhead supply nozzle.…”

“…Four studies have already tested the performance of TLA device. [22] investigated the effect of TLA treatment on reduction of particle and cat allergen exposure. The clinical effectiveness of TLA treatment in patients suffering from persistent allergic asthma has been investigated in three clinical studies [23, 24, 25].…”