Characterizing Risk Through Particle Size Analysis of Airborne Bacteria and Fungi in a Wholesale Traditional Fish Market

Wholesale traditional markets (WTMs) have established the most comprehensive and advanced auction systems for fresh seafood, meat, and fruits. Understanding the levels of bioaerosols of different sizes in WTMs can help to develop strategies to reduce the spread of infectious diseases. This study was aimed at analyzing and comparing the size distributions of culturable airborne bacteria (AB) and airborne fungi (AF) in a typical wholesale traditional fish market (WTFM). The AB and AF concentrations in the WTFM were relatively both high during and after the operation. The average AB concentration significantly increased from 4.73 × 10³ during operation to 8.58 × 10³ CFU/m³ after operation. The highest concentration of AB was observed at the fourth stage (2.1–3.3 μm), accounting for 26.22% and 28.15% of the total AB measured during and after operation, respectively. The average AF concentration remained steady from 2.77 × 10³ during operation to 2.53 × 10³ CFU/m³ after operation. The fourth stage also showed the highest AF concentration postoperation, comprising 35.47% of the total AF measured. Particles in this size range can be easily inhaled and deposited in the bronchial tubes, posing significant health risks. This study identified four and two types of possible pathogenicity in dominant AB and dominant AF, respectively. Commonly pathogenic Flavobacterium spp. frequently found in seafood and the highly pathogenic AF species Aspergillus tamarii and Aspergillus ochraceus were also detected. These pathogens and ultrafine biological aerosols (< 1 μm) can induce respiratory conditions such as aspergillosis. Based on these findings, the WTFM management should implement targeted interventions to reduce the concentration of harmful particles.