TABLE 1.

Bacteria and spore recovery from bathroom hand dryer air or environmental air^a

Location	No. and types of bathrooms	Environmentb		Hand dryersc
		Total no. of colonies/plate	No. of KSF/plate	Total no. of colonies/plated	No. of KSF/platee	% KSFf
Building 1	7 M, 7 W	0.21 ± 0.57	0	17.7 ± 10.1	0.68 ± 0.93	3.85
Building 2	7 M, 7W	0	0	23.8 ± 23.3	1.16 ± 1.07	4.87
Academic building	4 M, 4 W	1 ± 1.46	0	59.5 ± 60.2	1.5 ± 1.4	2.52

^aPlates were exposed to the bathroom environment for 2 min or for 30 s under hand dryers in men's (M) or women's (W) bathrooms on various floors in research buildings 1 and 2 and on research floors above the academic building, and total bacteria and levels of Km^r sporeformers (KSF) were quantified, all as described in Materials and Methods. Values for total colony number and number of Km^r sporeformers are averages ± standard deviations.

^bThe range of numbers of colonies per individual open plate exposed to the bathroom environment for 2 min was 0 to 3. Exposure of two open plates to bathroom environmental air for 18 h in two bathrooms yielded 2, 4, 8, and 10 colonies (average, 6 ± 3.65).

^cThe range of total colonies per individual plate exposed to a bathroom hand dryer air for 30 s was 3 to 254.

^dThe plates exposed to bathroom hand dryer air in research areas above the academic building had significantly higher numbers of total colonies than the those in research building 1 (P < 0.001) and research building 2 (P < 0.001). There was no statistical difference between the numbers of colonies recovered from bathrooms in research building 1 and those from building 2 (P = 0.235).

^eHand dryer air in research building 2 bathrooms had significantly fewer Km^r sporeformers than either bathrooms in research building 1 (P = 0.025) or bathrooms in the research area above the academic building (P = 0.016). There was no difference in numbers of Km^r sporeformer recovered from bathrooms in building 1 and those for the research areas above the academic building (P = 0.440).

^fThere was also a statistically significant difference in the percentages of Km^r sporeformers recovered from hand dryer air in bathrooms in buildings 1 and 2 (P = 0.044) and the percentages in building 1 and above the academic building (P < 0.001), but not for the percentages for building 2 and above the academic building (P = 0.306).