撞击法和自然沉降法监测室内空气细菌总数捕获效果的研究

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

目的探讨自然沉降法和撞击法监测室内细菌总数的捕获效果。方法使用自然沉降法(平皿暴露10min)和撞击法(FA-1型撞击式空气微生物采样器)对课室、实验室、办公室同步采样;同时用撞击法以28.3L/min分别进行1min、10min、15min空气采样结果的监测。结果撞击法和自然沉降法测得空气细菌总数间存在显著的正的线性相关关系;与自然沉降法比较,撞击法捕获空气细菌的效率更高(F方法=147.825,P=0.000);撞击法采样15min时所采空气细菌总数下降(F=17.171,P<0.001)。结论撞击法的灵敏度更高,能客观地反映出不同清洁程度场所的室内细菌含量的差异;撞击法采样时间较长时,捕获空气细菌效率下降。

Objective To explore the effects of two air sampling methods including-precipitation method and impacting method, for detecting the bacterial count of indoor air. Methods The indoor air was sampled by using two sampling methods simultaneously. The natural precipitation method was performed for 10-minute exposure, and the impacting method was performed by FA-1 airborne bacteria sampler at flow rate of 28.3 L/min for 1 min, 10 min and 15 min. All data of the bacterial counts of air obtained from various sampling ways were statistically analyzed. Results There was a significant correlation between the bacterial counts collected by precipitation and impacting methods. Compared with precipitation, the impacting method has better efficiency in collecting bacteria in the air; （F 方法=147.825,P=0.000）;the bacterial count tended to drop when the air was sampled for 15 min （F= 17.171, P〈0.001 ）. Conclusion The impacting method is more sensitive and reflecting the difference in the clearness of the air in different indoor environment. However, the sensitivity will drop when using a longer time for collecting sample.