Table 2.

Distribution of exposure by site and exposure averaging time period for eligible ARIC-NCS participants.

Exposure	Site	Time period	Mean	SD	Minimum	25th Percentile	75th Percentile	Maximum
${\mathrm{PM}}_{2.5}$	MN	1990–1998	9.4	0.4	7.7	9.2	9.6	11.5
${\mathrm{PM}}_{2.5}$	MN	1999–2007	13.1	0.7	9.3	12.9	13.4	16.7
${\mathrm{PM}}_{2.5}$	MN	1990–2007	11.2	0.5	9.0	11.1	11.5	13.9
${\mathrm{PM}}_{2.5}$	MD	1990–1998	15.1	1.0	11.8	14.6	15.9	18.2
${\mathrm{PM}}_{2.5}$	MD	1999–2007	19.1	1.8	9.9	18.5	20.1	22.9
${\mathrm{PM}}_{2.5}$	MD	1990–2007	17.1	1.3	11.4	16.5	17.9	20.5
${\mathrm{PM}}_{2.5}$	NC	1990–1998	15.7	0.5	13.8	15.4	16.0	17.7
${\mathrm{PM}}_{2.5}$	NC	1999–2007	11.4	0.7	8.7	11.1	11.7	18.9
${\mathrm{PM}}_{2.5}$	NC	1990–2007	13.6	0.5	11.6	13.4	13.8	16.7
${\mathrm{PM}}_{2.5}$	MS	1990–1998	12.4	0.3	11.6	12.2	12.5	13.3
${\mathrm{PM}}_{2.5}$	MS	1999–2007	10.2	0.3	8.7	10.1	10.4	11.3
${\mathrm{PM}}_{2.5}$	MS	1990–2007	11.3	0.2	10.4	11.2	11.4	12.3
${\mathrm{PM}}_{10}$	MN	1990–1998	17.0	1.2	12.1	16.6	17.6	20.0
${\mathrm{PM}}_{10}$	MN	1999–2007	16.6	1.8	10.5	16.2	17.5	21.6
${\mathrm{PM}}_{10}$	MN	1990–2007	16.8	1.4	11.5	16.3	17.5	20.6
${\mathrm{PM}}_{10}$	MD	1990–1998	23.3	2.3	16.2	22.0	25.1	30.2
${\mathrm{PM}}_{10}$	MD	1999–2007	19.4	2.1	13.5	18.0	20.9	25.5
${\mathrm{PM}}_{10}$	MD	1990–2007	21.4	2.1	15.5	20.1	22.9	27.8
${\mathrm{PM}}_{10}$	NC	1990–1998	21.9	0.9	18.6	21.3	22.3	24.8
${\mathrm{PM}}_{10}$	NC	1999–2007	18.2	0.8	14.4	17.7	18.5	20.8
${\mathrm{PM}}_{10}$	NC	1990–2007	20.0	0.8	16.9	19.5	20.4	22.7
${\mathrm{PM}}_{10}$	MS	1990–1998	18.7	0.5	17.1	18.3	18.9	20.0
${\mathrm{PM}}_{10}$	MS	1999–2007	17.4	0.5	15.9	17.1	17.6	18.9
${\mathrm{PM}}_{10}$	MS	1990–2007	18.0	0.5	16.6	17.7	18.3	19.4

Note: ARIC-NCS, Atherosclerosis Risk in Communities Neurocognitive Study; MD, Maryland; MN, Minnesota; MS, Mississippi; NC, North Carolina; PM, particulate matter; SD, standard deviation.