Table 1 Summary of smoke-free vs smoking places by country

Country	Smoking observed?	n	Mean active smoker density*	Geometric mean PM_2.5 (μg/m3) (95 CI for geometric mean)	PM_2.5ratio smoking/smoke-free (95 CI for ratio)
Argentina		142	0.41	26 (22 to 31)	3.5 (2.4 to 5.0)
	No	104	0.00	19 (16 to 22)
	Yes	38	1.54	65 (46 to 91)
Armenia		44	1.71	70 (42 to 119)	6.0 (1.8 to 19.6)
	No	9	0.00	17 (4 to 67)
	Yes	35	2.14	101 (60 to 171)
Belgium		68	1.67	229 (167 to 314)	14.9 (8.0 to 27.5)
	No	6	0.00	20 (4 to 92)
	Yes	62	1.72	291 (225 to 376)
Brazil		78	0.89	78 (63 to 97)	2.0 (1.3 to 3.0)
	No	43	0.00	58 (45 to 74)
	Yes	35	2.14	114 (79 to 163)
Canada		20	0.20	23 (12 to 45)	14.8 (8.0 to 27.5)
	No	13	0.00	9 (6 to 13)
	Yes	7	0.57	133 (69 to 257)
China		92	0.38	167 (137 to 203)	2.2 (1.4 to 3.4)
	No	20	0.00	91 (55 to 153)
	Yes	72	0.49	197 (161 to 241)
Faroe Islands		44	1.01	52 (30 to 90)	15.4 (7.1 to 33.2)
	No	18	0.00	10 (6 to 19)
	Yes	26	1.79	158 (96 to 258)
France		59	1.99	128 (82 to 200)	14.6 (6.7 to 31.6)
	No	14	0.00	18 (9 to 35)
	Yes	45	2.56	238 (159 to 354)
Germany		100	1.77	198 (160 to 247)	11.7 (3.6 to 38.2)
	No	3	0.00	18 (7 to 45)
	Yes	97	1.82	214 (174 to 263)
Ghana		86	6.77	299 (214 to 417)	37.0 (23.4 to 58.6)
	No	14	0.00	15 (11 to 20)
	Yes	72	8.10	537 (442 to 653)
Greece		51	2.66	205 (162 to 259)	4.1 (1.6 to 10.3)
	No	3	0.00	54 (27 to 109)
	Yes	48	2.83	223 (178 to 280)
Ireland†	No	25	0.00	22 (16 to 31)	–
Laos	Yes	51	2.74	124 (100 to 154)	–
Lebanon	Yes	9	1.46	346 (201 to 594)	–
Malaysia		50	1.58	79 (57 to 110)	3.1 (1.5 to 6.5)
	No	11	0.00	33 (18 to 58)
	Yes	39	2.02	102 (71 to 146)
Mexico	Yes	19	1.02	93 (58 to 148)	–
New Caledonia	Yes	29	1.79	153 (96 to 244)	–
New Zealand	No	44	0.00	8 (6 to 12)	–
Pakistan	Yes	27	2.75	113 (75 to 168)	–
Poland		74	0.98	98 (69 to 140)	5.2 (2.9 to 9.5)
	No	41	0.00	46 (31 to 68)
	Yes	33	2.20	241 (151 to 385)
Portugal		28	0.98	144 (102 to 204)	3.0 (1.4 to 6.2)
	No	5	0.00	56 (35 to 89)
	Yes	23	1.16	178 (123 to 256)
Romania		41	2.71	366 (292 to 460)	8.2 (2.2 to 31.3)
	No	1	0.00
	Yes	40	2.78	386 (313 to 475)
Singapore		15	1.74	131 (50 to 344)	22.6 (9.5 to 53.7)
	No	6	0.00	20 (13 to 32)
	Yes	9	2.71	456 (227 to 916)
Spain		13	0.31	89 (34 to 233)	12.5 (4.0 to 39.1)
	No	6	0.00	23 (8 to 64)
	Yes	7	0.78	287 (125 to 657)
Syria	Yes	40	6.42	372 (296 to 468)	–
Thailand		53	0.68	60 (42 to 86)	6.3 (3.7 to 10.6)
	No	29	0.00	26 (22 to 32)
	Yes	24	1.53	164 (95 to 283)
Tunisia		33	2.37	147 (94 to 230)	7.1 (3.8 to 13.3)
	No	12	0.00	43 (24 to 76)
	Yes	21	3.73	328 (242 to 445)
UK	Yes	64	2.28	193 (153 to 242)	–
USA		227	0.73	89 (74 to 107)	11.4 (8.8 to 14.9)
	No	64	0.00	15 (12 to 19)
	Yes	163	1.03	177 (153 to 203)
Uruguay		66	0.01	18 (13 to 24)	1.9 (0.8 to 4.6)
	No	63	0.00	17 (14 to 22)
	Yes	3‡	0.18	33 (10 to 103)
Venezuela		80	0.96	46 (32 to 65)	10.3 (5.7 to 18.5)
	No	24	0.00	9 (7 to 12)
	Yes	55	1.38	92 (64 to 132)
Vietnam		49	0.77	165 (121 to 224)	2.3 (0.8 to 6.9)
	No	4	0.00	77 (38 to 156)
	Yes	45	0.84	176 (127 to 244)

*Active smoker density is the average number of burning cigarettes and waterpipes per 100 m3. Waterpipes were observed in Lebanon (n 6), Pakistan (n 1), Syria (n 20) and Tunisia (n 8).
†The data for Ireland is from another study and serves as a reference group to the data in this study (Mulcahy et al, 2006).¹⁸
‡While all locations sampled in Uruguay were supposed to be smoke-free by law, smoking was observed in three venues in violation of the law.
PM_2.5, particulate matter less than 2.5 microns in diameter.