Table 2.

Black Carbon (μg/m³) Exposure before Lung Function Assessment for 2,410 Visits Undergone by 858 Men Participating in the Normative Aging Study, 1995–2011

Exposure Window	Statistics
	Number of Observations	Mean ± SD	5th, 95th Percentiles	Interquartile Range
1 wk	2,392	0.6 ± 0.4	0.2, 1.4	0.42
1 yr	2,410	0.7 ± 0.3	0.3, 1.2	0.39
2 yr	2,175	0.6 ± 0.3	0.3, 1.2	0.37
3 yr	1,943	0.6 ± 0.3	0.3, 1.1	0.37
4 yr	1,720	0.6 ± 0.3	0.3, 1.1	0.35
5 yr	1,508	0.6 ± 0.3	0.3, 1.1	0.34