Evaulation of Air-borne Bacteria in Dormitories and Canteen of a Shanxi University

The air-borne bacteria amount of 105 dormitories and canteen sampled in a Shanxi university has been determined based on the method of the gravity plate. The result shows that, when with people indoors, the air-borne bacteria concentration at lower floors of male students' dormitories is prominently larger than that at higher floors (p < 0.05), and air-borne bacteria concentration at all floors of female students' dorms has no sense in statistics (p > 0.05); And the air-borne bacteria concentration in male students is obviously larger than that of female ones. The air-borne bacteria concentration at lower floors of canteen is clearly larger than that of higher ones (p < 0.05) When without people in at, the air-borne bacteria concentration in either dorms or canteen has no sense in statistics. The result also indicates that the total of bacteria when there are people in is obviously higher than that without people in, no matter within males dorms or females' dorms, or within all floors of canteen (p < 0.05). Except that the total of bacteria at the first floor of the canteen is above the standard (2.5 x 103cfu/m(3)), which can be classified as slight pollution, the bacteria concentration of the total within dorms and at all floors of canteen is lower than the national standard, with the air quality being clean, comparatively clean and the air qualities are at national first level standard and second level standard, respectively.