Effects of ozone exposure on house dust mites.

House dust mites (HDMs), particularly Dermatophagoides farinae, are commonly found in household dust and play a key role in allergic diseases such as asthma and allergic rhinitis. Beyond clinical management, allergen removal strategies are crucial for improving quality of life. Hence, this study investigated the effects of ozone exposure on D. farinae, focusing on changes in protein expression, surface bacterial composition, mortality, and mobility. Mites were exposed to ozone concentrations of 0.05, 0.5, and 1 ppm for 24, 48, and 72 h in a controlled chamber, with non-exposed mites serving as controls. Western blotting using anti-Der f 1 and anti-Blo t 5 antibodies assessed changes in allergen profiles, while 16 S rRNA sequencing characterised changes in surface bacterial communities. Mortality was evaluated using 100 mites per group under varying exposure durations. To assess behavioural responses, a three-chamber mobility assay was conducted, where mites were placed in a central compartment flanked by no-ozone and low-ozone chambers, and their distribution was recorded after 72 h. Ozone exposure resulted in a concentration- and time-dependent reduction of Der f 1 protein intensity, suggesting allergen degradation. Surface bacterial profiling revealed distinct compositional shifts following ozone exposure. Mortality increased proportionally with ozone concentration and duration. In the mobility assay, mites predominantly remained in the no-ozone chamber, indicating avoidance of ozone. Collectively, these findings demonstrate that ozone exposure affects D. farinae at molecular, microbial, and behavioural levels, highlighting ozone's potential role in modulating mite allergenicity and ecology.