Table 2.

Indoor and outdoor airborne bacterial concentrations per region.

Source	Region	n	Concentration (CFU/m3)		p	Duncan Coefficient
			Mean	SD *
Indoor	Industrial area	54	118.6	113.5	>0.05	a
	Urban area	64	217.7	594.0		a
	Forested area	72	154.4	372.4		a
Outdoor	Industrial area	54	45.9	35.5	<0.05	a
	Urban area	65	74.9	59.7		b
	Forested area	72	50.1	40.6		a

* SD: Standard deviation.