雾霾天气下佩戴防颗粒物口罩的微生物学评价研究

目的 对在雾霾天气下佩戴的日常自吸式防颗粒物口罩进行微生物学评价,并给出推荐的累计佩戴时间,提高公众健康防护水平。 方法 选取在雾霾天气下佩戴的自吸式防颗粒物口罩,记录口罩基本情况,分别对其外层及内层材料进行细菌总数、真菌总数、溶血菌总数的检测,利用16S rRNA基因鉴定纯化菌株的生物学分类,并将微生物指标与口罩累计佩戴时间进行相关性拟合。 结果 日常自吸式防颗粒物口罩内层材料上附着的微生物与口罩累计佩戴时间呈现正相关,模拟出两条拟合度较高的多项式预测曲线(R²_细菌总数=0.994,R²_真菌总数=0.965),而外层材料的微生物与口罩累计佩戴时间无明显相关性。在累计佩戴时间为5~7 h时,口罩内层材料中细菌总数和真菌总数呈现急速增长。在口罩内、外层材料中分离纯化的菌株主要分属厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)和变形菌门(Proteobacteria),其中以厚壁菌门芽孢杆菌目(Bacillales)细菌最多。大部分纯化菌株为环境非致病菌,仅在口罩内层材料上分离到一株金黄色葡萄球菌。 结论 随着口罩累计佩戴时间增长、累计佩戴次数增加,口罩内层材料中微生物浓度相应增加,在累计佩戴时间为5~7 h时,微生物浓度急速增加,致病菌或条件致病菌检出率增高。建议健康人群在佩戴同一防护口罩时累计时间控制在7 h以内,而免疫力低下人群累计佩戴时间应控制在5 h以内。

Microbiological assessment of wearing the particulate respirator during haze days

Objective To perform an assessment of microbiological contamination on daily self-inhaling respirator for particulate during haze days so as to provide the recommended cumulative wearing time and improve the protective level of public health. Methods The used particulate respirators during haze days were collected, and their basic information was recorded. The total bacterial count, total fungal count and hemolytic bacteria count of inner and outer materials of the respirators were detected separately. The strains were identified by 16S rRNA gene sequence analysis, and the fitting curves of microbiological indicators and cumulative wearing time were drawn. Results The amount of microorganism attached to inner materials of daily self-inhaling respirators was positively correlated with the cumulative wearing time, and the fitting curve of the total bacterial count and total fungal count was drawn (R² _{total bacterial count}=0.994, R² _{total fungal count}=0.965). There was no obvious correlation between the amount of microorganism attached to outer materials and the cumulative wearing time. The total bacterial count and the total fungal count in inner materials of the respirators both increased rapidly when the cumulative wearing time was up to 5-7 hours. The isolated bacterial strains from inner and outer materials of the respirators were mainly Firmicutes, Actinobacteria and Proteobacteria, especially Bacillales. Most of the isolated strains were non-pathogenic bacteria, and only one strain of Staphylococcus aureus was isolated from the inner materials. Conclusions The amount of microorganism attached to inner materials increases with the increment of cumulative wearing time and frequency; moreover, it rapidly increases and the detection rate of pathogenic or conditional pathogenic bacteria also increases when the cumulative wearing time is up to 5-7 hours. So the cumulative wearing time of a respirator should be controlled under 7 hours by healthy people and under 5 hours by susceptible people.