广州市部分菜市场空气的微生物污染状况

Investigation of Air Bacteria Pollution of Markets in Guangzhou

目的调查广州市菜市场空气微生物的污染状况和传播规律,为公共场所空气致病微生物的防治和预警提供参考。方法于2003年11月—2005年6月在不同的气象条件下,采用自然沉降法,对广州市8个菜市场活禽区、肉类区、蔬菜区进行空气微生物污染的现场采样研究;检测空气中细菌总数和金黄色葡萄球菌菌落数并进行模拟实验。结果广州市菜市场活禽区、肉类区、蔬菜区空气中细菌总数和金黄色葡萄球菌菌落数分别为95～15000、2～12000cfu/皿;52～6700、11～930cfu/皿;2～710、4～250cfu/皿,在17:00—19:00出现日峰值;在静风条件下,市场内的空气微生物以活禽区为中心,按二次方程扩散模式向外传播,数量随扩散距离增大而减少,临界距离约为24～26m。结论菜市场空气细菌总数普遍高于GB9670—1996《商场(店)、书店卫生标准》中的规定限值(细菌总数≤75cfu/皿)。活禽是菜市场中主要的带菌生物,是菜市场空气微生物传播的主要污染源。

Objective To investigate air bacteria pollution and the rule of microbes spread in some markets in Guangzhou, aiming at prevention and forecast airborne pathogenic microbes. Bacteria and Staphylococcus aureus were collected to provide reference on evaluation and of the spread of through the air in public. Methods Gravity exposure of microbial media plates was used to sample the airborne bacteria in eight different markets in Guangzhou on a given day, from 2003 to 2005. The simulated experiment in the laboratory was conducted based on the results of natural sampling stations. Results Samples taken at different times showed wide variations with quantities of airborne bacteria （total count） and Staphylococcus aureus ranged from 95 to 1.5×10^4 cfu per petri dish and from 2 to 1.2×10^4 cfu per petri dish respectively. Movement of airborne bacteria in the market obeyed quadratic equation pattern. The spread distance of airborne bacteria was among 24 to 26 meters. Maximum airborne bacteria were detected from 17：00 o＇clock to 19：00 o＇clock in a day. Conclusion The count of market airborne bacteria is markedly more than the limits stipulated in the related national standard GB 9670-1996. Live fowls sold in the markets are the main carriers of bacteria and the potential pollution resource of pathogenic bacteria.