Characterization of Bioaerosol Distribution in Ambient Air With Different Toilettoileting Practices

To clarify the potential health risks of bioaerosols in the toilet environment in rural areas and improve the quality of life of villagers, different types of toilets in four northwestern provinces (Shanxi, Shaanxi, Qinghai, and Inner Mongolia) were selected, and the bioaerosol characteristics there were studied. Results show that the average number of culturable bacterial colonies in the bioaerosol from dry toilet is 21954 Colony forming units/m³, and the average culturable bacterial colonies in the bioaerosol from water flushing toilet are 4488 Colony forming units/m³. Similarly, the number of culturable fungi and enterobacter colonies in bioaerosol in the dry toilet is larger than that in the water flushing toilet. Due to hydraulic shear, the aerodynamic diameter of the bioaerosols in the water flushing toilet is smaller, with bioaerosols of 0.65-3.3 μm, accounting for 55.61%, while the bioaerosols in the dry toilet are mainly dominated by large particle sizes, with bioaerosols of particle sizes >3.3 μm, accounting for 54.33%. At the same time, there are some differences in the potential pathogenic microorganisms in the bioaerosols of dry toilet and water flushing toilet, with Helicobacter, Fusobacterium, and Saccharomyces as the unique pathogenic bacteria in dry toilet, and Anaerococcus, Proteus, and Rhizopus in water flushing toilet. The results of the exposure risk assessment show that the health risk of dry toilet > water flushing toilet, and the health risk of bacteria > fungi.