Comprehensive analysis of resilience of human airway epithelial barrier against short-term PM2.5 inorganic dust exposure using in vitro microfluidic chip and ex vivo human airway models.

BACKGROUND AND OBJECTIVE: The updated World Health Organization (WHO) air quality guideline recommends an annual mean concentration of fine particulate matter (PM2.5) not exceeding 5 or 15 µg/m3 in the short-term (24 h) for no more than 3-4 days annually. However, more than 90% of the global population is currently exposed to daily concentrations surpassing these limits, especially during extreme weather conditions and due to transboundary dust transport influenced by climate change. Herein, the effect of respirable