Table 2. Aerosol studies on electronic cigarettes and the puff topography used.

Study	Puff Duration	Puff Volume	Time between Puffs
(1) Westenberger	Not Reported	100 mL	Not Reported
(2) Trtchounian	2.2 sec	Not Reported	1 min
(3) Trehy	2 sec	100 mL	1 min
(4) Williams	2.2 sec	NR	1 min
(5) Goniewicz	1.8 sec	70 mL	10 sec
(6) Goniewicz	1.8 sec	70 mL	10 sec
(7) Goniewicz	1.8 sec	70 mL	10 sec
(8) Kosmider	1.8 sec	70 mL	17 sec

Studies included in each row of the table include (1) Westenberger [21], (2) Trtchounian [22], (3) Trehy [23], (4) Williams [24], (5) Goniewicz [17], (6) Goniewicz [25], (7) Goniewicz [26], and (8) Kosmider [27].