Table 3.

Surface nicotine loading, dust nicotine loading, and dust nicotine concentration before and after cleaning for the three cleaning groups combined (N = 38)

			Percent change
	GeoMean µg/m2	95% Confidence Interval	vs. BL0	vs. BL1
Surface nicotine concentrations (µg/m 2)
Baseline 0—screening	21.58a,b	[12.90; 35.69]	Ref
Baseline 1	20.47c,d	[10.56; 38.86]	−5%	Ref
Sequential or combined dry/damp and wet cleaning
Posttest 2	11.59a,c	[6.58; 19.92]	−46%	−43%
Follow-up month 3	9.58b,d	[5.64; 15.87]	−56%	−53%
Dust nicotine loading (µg/m 2)
Baseline 1	1.23a	[0.62 2.06]		Ref
Sequential or combined dry/damp and wet cleaning
Posttest 2	0.50a	[0.22 0.83]		−60%
Follow-up month 3	0.91	[0.55 1.35]		−26%
Dust nicotine concentration (µg/g)
Baseline 1	1.47	[1.07 1.95]		Ref
Sequential or combined dry/damp and wet cleaning
Posttest 2	1.30	[0.87 1.83]		−12%
Follow-up month 3	1.64	[1.18 2.19]		+11%

Reference group for the calculation of the percent change in GeoMeans.

^a,b,c,d For each of the nicotine measures, pairs of letters indicate significant differences in GeoMeans (p < .05).