Table 2. Air Quality Measures Across 2 Low-Income Subsidized Housing Settings in NYC Before vs 12 Months After SFH Policy Implementation^a.

Variable	Before SFH policy		12 mo After SFH policy
	NYCHA	Section 8	NYCHA	Section 8
Airborne nicotine
Stairwells
No.	20	19	20	21
Level, geometric mean (SD), μg/m3	0.43 (0.11)	0.24 (0.10)	0.32 (0.05)	0.17 (0.06)
Proportion above LOD, %	95.0	78.9	100	85.7
Hallways
No.	19	23	25	23
Level, geometric mean (SD), μg/m3	0.45 (0.16)	0.09 (0.03)	0.21 (0.06)	0.08 (0.02)
Proportion above LOD, %	89.5	60.9	84.0	73.9
Nonsmoking apartments
No.	153	110	124	98
Level, geometric mean (SD), μg/m3	0.023 (0.002)	0.019 (0.001)	0.024 (0.002)	0.023 (0.002)
Proportion above LOD, %	13.1	5.5	24.2	16.3
Particulate matter <2.5 μm
Nonsmoking apartments
No.	137	105	126	99
Level, mean (SD), μg/m3	22.10 (10.80)	19.48 (10.49)	20.78 (11.26)	16.71 (7.35)
Above EPA standard, %	89.8	74.3	80.9	77.8
Cigarette butt count
Stairwells
No.	10	11	10	11
Count, mean (SD)	9.85 (7.76)	10.32 (7.98)	8.85 (5.35)	4.13 (3.72)
Hallways
No.	10	11	10	11
Count, mean (SD)	4.35 (5.20)	0.95 (1.08)	2.15 (1.73)	0.45 (0.61)

Abbreviations: EPA, Environmental Protection Agency; LOD, limit of detection; NYC, New York City; NYCHA, NYC Housing Authority; SFH, smoke-free housing.

^aMeasures before the policy are from summer 2018, and measures after the policy are from summer 2019; all measures were taken from 10 NYCHA buildings and 11 Section 8 buildings.