自然沉降法和撞击法在空气细菌总数测定中的应用和比较  

Application and Comparation Study of Natural Precipitation Method and Impacting Method for Measurement of Bacterial Count of Air

作　　者：钟嶷[1] 郭重山[1] 李小晖[1] 李锦光[1] 冯文如[1] 杨惠贤[1] 

机构地区：[1]广州市疾病预防控制中心,广东广州510080

出　　处：《环境与健康杂志》2004年第3期149-152,共4页Journal of Environment and Health

基　　金：广东省重点科技项目(2KM06402S)

摘　　要：目的探讨自然沉降法和撞击法进行空气采样对化妆品生产车间空气细菌总数测定结果的影响。方法测量了44只实验用玻璃平皿的直径;用自然沉降法(平皿暴露5min)和撞击法穴MAS鄄100空气微生物采样器雪在化妆品生产车间同步采样;同时用撞击法以100L/min进行30s、2min、8min的空气采样,对不同采样方法所测定的空气细菌总数进行分析,并探讨了实验过程中的质量控制。结果44只玻璃平皿直径为8.39～8.70cm,均小于标准直径(9.00cm)。与撞击法比较,同一环境的空气经沉降法采样所测定的空气细菌总数变异系数较大,中位数较高,合格率较低。撞击法采样8min时(800L)所测定的空气细菌总数下降。结论撞击法受环境因素影响小,精确度较好,一般情况下可优先采用,但采样时间较长(空气采样体积较大)时,捕获空气细菌效率下降。沉降法测定结果精确度较差,适宜在空气流速小且稳定、空气洁净度高、需要较长采样时间(8～30min)的环境采用。当沉降法采用的玻璃平皿直径不等于9cm时,测定结果需要校正。Objective To explore the effects of two air sampling methods including natural precipitation method and impacting method for detecting the bacterial count of indoor air of workplace of cosmetic plants. Methods The diameters of 44 glass bacteria-culture plates for those two sampling methods were measured. The indoor air of workplace of cosmetic plants were sampled by those two sampling methods simultaneously. The natural precipitation method was performed for 5- minute exposure ,the impacting method was performed by MAS-100 airborned bacteria sampler at flow rate of 100 L/min for 30 s,2 min,8 min respectively.All of the data on the bacterial counts of air obtained from various sampling ways were statistically analyzed.The measures for quality control of air sampling progress were put forward also. Results The diameters of 44 glass bacteria-culture plates were 8.39-8.70 cm,which were lower than the standard(9 cm?雪. The bacterial counts of air samples collected by natural precipitation method at the same location showed higher coefficient of variation,higher median,lower qualified rate compared with those by impacting method. The bacterial counts of air decreased,when the impacting sampling method was performed for 8 min continuously with sampling volume of 800 L. Conclusion The impacting method with advantages including mere influence from external environment and better precision could be primarily applied for air sampling in general condition,but it might show lower efficiency of collecting the airborne bacteria during the longer sampling period with higher sampling volume. The natural precipitation method with poor precision was suitable for longer term (8-30 min)air sampling in the relatively static environment with lower air flow and highly cleaned air. The bacterial counts of air obtained from natural precipitation method should be corrected if the diameters of glass bacteria-culture plates weren't meet the requirement of the national standard (9 cm?雪.

关 键 词：菌落计数 微生物 空气 采样方法 自然沉降法 撞击法 

分 类 号：R122.1[医药卫生—环境卫生学]