Table 2 Location-level analysis of the change in concentrations of respirable suspended particles after implementation of a smoking ban, stratified by smoking status—North Carolina, 2005–6

Prison type	Size (m³)	Average number of burning cigarettes per 100 m³		Average particulate matter (PM_2.5) less than 2.5 μg/m³		% Reduction in PM_2.5
Prison type	Size (m³)	Before tobacco ban	After tobacco ban	Before tobacco ban	After tobacco ban	% Reduction in PM_2.5
Prison areas where smoking was directly observed in 2005 (n = 14)
P1-Dorm area 1	1712	0.06	0.00	NA	NA	NA
P1-Dorm area 2	1019	0.15	0.00	110.50	10.77	0.90
P2-Dorm area 3	1557	0.08	0.00	83.25	153.45	0.46*
P2-Dorm area 4	1557	0.14	0.02†	NA	NA	NA
P4-Dorm area 5	679	0.07	0.00	24.89	26.15	0.05*
P4-Dorm area 6	679	0.24	0.00	73.13	7.78	0.89
P4-Dorm area 7	679	0.12	0.00	45.89	6.28	0.86
P6-Dorm area 8	238	0.76	0.00	117.51	8.00	0.93
P6-Dorm area 9	93	1.51	0.00	304.93	6.50	0.98
P1-Lobby/office 10	88	1.89	0.00	193.85	7.65	0.96
P6-Lobby/office 11	31	0.00	0.00	30.08	3.64	0.88
P3-Dorm area 12	219	2.01	0.00	34.65	11.78	0.66
P5-Dorm area 13‡	340	0.06	0.00	31.08	10.22	0.67
P3-Dorm area 14¶	64	6.28	0.00	67.59	9.57	0.86
Mean§	640	0.95	0.00	93.11	21.82	0.77
Prison areas where smoking was not directly observed and had a locally imposed rule banning tobacco indoors (n = 8)
P3-Dorm area 15	219	0.00	0.00	15.58	10.24	0.34
P6-Dorm area 16	238	0.00	0.00	12.04	5.63	0.53
P5-Dorm area 17	340	0.00	0.00	11.56	5.93	0.49
P5-Dorm area 18	340	0.00	0.00	16.21	6.84	0.58
P2-Lobby/office 19	28	0.00	0.00	12.19	7.79	0.36
P3-Lobby/office 20	82	0.00	0.00	10.99	8.57	0.22
P4-Lobby/office 21	170	0.00	0.00	3.70	9.79	1.65*
P5-Lobby/office 22	41	0.00	0.00	6.83	5.32	0.22
Mean§	182	0.00	0.00	11.14	7.52	0.33

NA, technical difficulties. Air monitoring not completed at these sites at baseline.
*Percentage increase in PM_2.5 rather than a percentage reduction.
†Non-compliant prison at follow-up. Directly observed smoking by study team.
‡Dorm area 13 had a non-smoking policy but directly observed smoking occurred during monitoring at baseline.
¶Dorm area 14 was an outside shelter area directly adjacent to a common dorm area door designated for smokers.
§Results represent the average of the values for the venues listed in each category.