Instrumentation Shortcomings in Asthma Studies: Implications for Accurate Particle Measurement and Health Outcomes

DAVID WOOLSEY, Mohammadreza Khani, AirSpeQ

     Abstract Number: 699
     Working Group: Instrumentation and Methods

Abstract
Understanding the behavior of aerosol particulates is crucial in asthma research, particularly the distinction between particles above and below 300nm, characterized by inertial versus diffusive behavior. In the lungs, sub-300nm particles, dominated by diffusion, tend to deposit on less wetted structures, potentially penetrating more directly into the bloodstream. Larger particles, dominated by inertia, settle on mucous-wetted surfaces, inhibiting direct penetration. This distinction may lead to different immune responses, a novel aspect to explore in asthma research.

We reviewed asthma-related particulate matter (PM) studies published over the past 15 years, evaluating them against stringent criteria to determine their efficacy in linking sub-300nm PM to asthma episodes. Criteria included detection competence, size spectrum coverage, equipment colocation, proximity to subjects, and real-time monitoring.

Our findings reveal that no existing study meets all these criteria, rendering them unable to definitively link sub-300nm PM to asthma episodes. For instance, Ketzel et al. (2003) studied particle distribution in various environments but did not colocate all equipment. Similarly, Wu and Boor (2021) and Sipilä et al. (2021) provided valuable insights but lacked continuous monitoring close to patients.

This gap highlights the need for well-designed studies to accurately assess the impact of sub-300nm particles on asthma. Addressing these shortcomings will enhance understanding and lead to more precise health outcome assessments.

Funding: This work was partially supported by NIH grant contributions, with acknowledgments to past support from NSF and NASA.