คุณภาพอากาศทางด้านจุลชีววิทยาภายในโรงอาหารที่มีการระบายอากาศโดยวิธีกลและวิธีธรรมชาติ กรณีศึกษา หน่วยงานรัฐวิสาหกิจแห่งหนึ่ง

Abstract

The objectives of this research were to study and compared a number of airborne microorganisms in cafeterias that are ventilated by mechanical ventilation and natural ventilation located at a state enterprise. The amounts of total viable fungi, total viable bacteria, and hemolytic bacteria were enumerated at 3 seasons, including winter (January), summer (April) and rainy season (July). The results showed that the amount of total viable bacteria in the mechanical ventilation cafeteria was a significant difference among three seasons (P<0.05), while the amount of total viable fungi and hemolytic bacteria were no significant difference between three seasons. The natural ventilation cafeteria found that the amount of total viable fungi was a significant difference among three seasons (P<0.05), while the amount of total viable bacteria and hemolytic bacteria were no significant difference among three seasons. In comparison between the mechanical ventilation and the natural ventilation cafeterias in each season, it was found that the amount of total viable fungi between the two types of cafeterias was no significant difference in all seasons. In the winter, the amount of total viable bacteria in the mechanical ventilation cafeteria was significantly higher than that of the natural ventilation cafeteria (P<0.05). On the other hand, the amount of total viable bacteria in the natural ventilation cafeteria was significantly higher than that of the mechanical ventilation cafeteria in rainy season (P<0.05) that was similar to the amount of hemolytic bacteria in the natural ventilation cafeteria which was significantly higher than that of the mechanical ventilation cafeteria in rainy season (P<0.05). It could be concluded that the amount of airborne microorganisms in cafeterias depended on various factors including ventilation systems, temperature, relative humidity, air movement, and season.