. 2013 Dec 11;16(6):655–662. doi: 10.1093/ntr/ntt203

Table 1.

Changes in Nicotine, Aerosol Particles (PM_2.5), and Carbon Monoxide (CO) Air Concentration Inside Exposure Chamber After Use of E-Cigarette

Experiment	Exposure level	Ventilation	E-cigarette brand	Nicotine (µg/m³)		PM_2.5 (µg/m³)		CO (ppm vol/vol)
Experiment	Exposure level	Ventilation	E-cigarette brand	Baseline	E-cigarette	Baseline	E-cigarette	Baseline	E-cigarette
Experiments with smoking- machine (Study 1)
1	Low	High	EC1	BLD	0.82	12.7	33.0	1	1
2	Low	High	EC2	BLD	1.13	85.0	80.0	1	1
3	Low	High	EC3	BLD	3.42	25.3	29.0	1	1
4	Low	Low	EC1	BLD	0.88	33.0	43.7	1	1
5	Low	Low	EC2	BLD	2.52	59.7	63.0	2	2
6	Low	Low	EC3	BLD	2.38	12.0	15.0	2	2
7	High	High	EC1	BLD	0.92	11.3	15.3	2	2
8	High	High	EC2	BLD	2.45	71.3	85.0	2	2
9	High	High	EC3	BLD	4.52	50.7	64.3	2	2
10	High	Low	EC1	BLD	0.95	12.0	15.0	1	1
11	High	Low	EC2	BLD	4.15	17.3	23.3	2	2
12	High	Low	EC3	BLD	6.23	6.6	69.7	1	1
Average (Experiments 1–12)				BLD	2.53±1.75^a	33.1±26.9	44.7±26.4^a	1.50±0.52	1.50±0.52
		Nicotine (µg/m³)			PM_2.5 (µg/m³)			CO (ppm vol/vol)
		Baseline	E-cigarette	Tobacco cigarette	Baseline	E-cigarette	Tobacco cigarette	Baseline	E-cigarette	Tobacco cigarette
Experiments with dual product users (Study 2)
13	Smoker 1	BLD	0.65	26.9	80.0	63.3	690.0	1	1	3
14	Smoker 2	BLD	0.85	38.1	8.0	123.0	726.0	2	2	5
15	Smoker 3	BLD	5.02	25.6	13.3	91.3	661.3	2	2	3
16	Smoker 4	BLD	3.87	25.6	44.0	208.3	802.0	1	1	4
17	Smoker 5	BLD	6.23	41.8	16.7	272.7	1217.3	1	1	4
Average (Experiments 13–17)		BLD	3.32±2.49^a,b	31.6±7.8	32.4±30.0	151.7±86.8^a,b	819.3±228.6	1.40±0.55	1.40±0.55^b	3.80±0.84

Note. BLD = below limit of detection (0.22 µg/m³).

^aSignificant difference with baseline (p < .05).

^bSignificant difference with tobacco cigarette (p < .05).