不同如厕方式环境空气中生物气溶胶分布特征

Characterization of Bioaerosol Distribution in Ambient Air With Different Toilettoileting Practices

为阐明农村地区厕所环境中生物气溶胶的潜在健康风险,提升村民生活品质,选择西北四省(山西、陕西、青海、内蒙古)不同类型厕所,对其中生物气溶胶特性开展研究。结果表明,旱厕生物气溶胶中平均可培养细菌菌落数为21954个/m^(3),水冲厕生物气溶胶中平均可培养细菌菌落数为4488个/m^(3)。同样生物气溶胶中可培养真菌和肠杆菌菌落数也呈现旱厕大于水冲厕的现象。由于水力剪切作用,水冲厕中生物气溶胶空气动力学直径更小,其中0.65~3.30μm的生物气溶胶占比为55.61%;而旱厕中生物气溶胶则主要以大粒径为主,粒径>3.30μm的生物气溶胶占比高达54.33%。同时,旱厕和水冲厕生物气溶胶中潜在致病微生物也存在一定差异,旱厕独有致病菌为Helicobacter、Fusobacterium、Saccharomyces,水冲厕独有致病菌为Anaerococcus、Proteus、Rhizopus。暴露风险评估结果表明,旱厕暴露风险大于水冲厕暴露风险,细菌暴露风险大于真菌暴露风险。

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/m^(3),and the average culturable bacterial colonies in the bioaerosol from water flushing toilet are 4488 Colony forming units/m^(3).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 0.65-3.3μm,accounting for 55.61%,while the bioaerosols in the dry toilet are mainly dominated by large particle sizes,with bioaerosols of particle sizes>3.3μm,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.