The composition of microbial aerosols, PM2.5, and PM10 in a duck house in Shandong province, China.

Poultry-emitted air pollutants, including microbial aerosols and particulate matter, have raised concerns due to their potential negative effects on human health and the environment. High concentrations of microbial aerosols can also significantly affect duck production performance, leading to immunosuppression and increased disease susceptibility. We determined the concentrations, distributions, and biological components of the microbial aerosols and particulate matter in a duck house environment. The concentration ranges of the bacteria, fungi, Gram-negative bacteria, Escherichia coli, and endotoxin in the duck houses were 3.3 to 5.2 × 104 CFU/m3, 3.8 to 11.9 × 103 CFU/m3, 2.1 to 3.6 × 103 CFU/m3, 1.3 to 2.7 × 102 CFU/m3, and 0.65 to 2.2 × 103 EU/m3, respectively. We also found the endotoxin levels were higher than the standard that can cause pneumonia (2,000 EU/m3). The concentration ranges of the PM2.5 and PM10 samples were 1.1 to 1.6 × 102 µg/m3 and 1.2 to 1.9 × 102 µg/m3, respectively. At the phylum level, the top 5 bacteria identified in the PM2.5 fraction were Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes, and Fusobacteria, with Actinobacteria (50.55%) as the most abundant. At the genus level, 293 bacterial groups were identified. Actinobacteria (39.01%) was the most abundant phylum, followed by Firmicutes (5.44%) and Proteobacteria (4.56%). The bacterial distributions that differed between the PM2.5 and PM10 samples were Lactobacillales, Bacilli, Firmicutes, and Bacteroidetes; the fungi that differed were Microbotryomycetes, Sporidiobolales, Agaricomycetes, and Polyporates. Microbial allergens and pathogens were also identified. Corynebacterium had a relative abundance of more than 30% in the PM2.5 and PM10 distributions. Aspergillus was the main fungal allergen and opportunistic pathogen, with a relative abundance of 10%. In conclusion, our research supports that the microbial composition in the duck house environment poses a potential threat to the health of both the ducks and the duck house workers.