Table 2.
Descriptive Statistics (n=65,232 Census Tracts)
| Variables | Higher density urban mean (SD) n=15,120 | Low-density urban mean (SD) n=23,480 | Suburban/small town mean (SD) n=10,680 | Rural mean (SD) n=15,952 |
|---|---|---|---|---|
|
| ||||
| Life expectancy (year) | 77.95 (4.48) | 78.67 (4.01) | 78.48 (3.79) | 77.89 (3.55) |
| Population density (/mi2) | 17,017 (21,169) | 3,443 (1,884) | 1,070 (1,121) | 145 (215) |
| Blacka | 0.22 (0.29) | 0.14 (0.21) | 0.09 (0.16) | 0.07 (0.14) |
| Hispanica | 0.28 (0.27) | 0.17 (0.20) | 0.12 (0.17) | 0.07 (0.14) |
| Bachelor’s degree or abovea | 0.29 (0.21) | 0.33 (0.19) | 0.30 (0.17) | 0.19 (0.10) |
| Annual income ($) | 51,755 (27,149) | 64,293 (32,309) | 63,648 (30,258) | 49,702 (17,026) |
| Age under 18 yearsa | 0.23 (0.08) | 0.23 (0.06) | 0.24 (0.06) | 0.23 (0.05) |
| Age 18 to 34 yearsa | 0.27 (0.09) | 0.23 (0.08) | 0.21 (0.07) | 0.19 (0.05) |
| Age 35 to 64 yearsa | 0.38 (0.06) | 0.40 (0.06) | 0.40 (0.06) | 0.41 (0.05) |
| Age over 65 yearsa | 0.12 (0.06) | 0.14 (0.07) | 0.15 (0.07) | 0.17 (0.05) |
| Presence of childrena | 0.33 (0.13) | 0.33 (0.10) | 0.34 (0.10) | 0.30 (0.07) |
| Unemploymenta | 0.12 (0.07) | 0.09 (0.06) | 0.09 (0.05) | 0.09 (0.05) |
| No vehicle availablea | 0.21 (0.19) | 0.07 (0.07) | 0.06 (0.06) | 0.05 (0.04) |
| Foreign borna | 0.24 (0.18) | 0.13 (0.11) | 0.08 (0.08) | 0.04 (0.05) |
| Limited healthy foodb | 0.39 (0.37) | 0.27 (0.31) | 0.58 (0.34) | 0.10 (0.22) |
| Liquor store/1,000 people | 0.19 (0.33) | 0.16 (0.30) | 0.14 (0.27) | 0.13 (0.27) |
| Tobacco store/1,000 people | 0.04 (0.14) | 0.04 (0.12) | 0.03 (0.10) | 0.02 (0.12) |
| Convenience store/1,000 people | 0.22 (0.35) | 0.25 (0.35) | 0.29 (0.38) | 0.36 (0.39) |
| Gas station/1,000 people | 0.00 (0.01) | 0.00 (0.01) | 0.00 (0.02) | 0.00 (0.02) |
| Fast food/1,000 people | 0.44 (0.74) | 0.59 (0.84) | 0.49 (0.71) | 0.32 (0.48) |
| Bar/1,000 people | 0.35 (0.73) | 0.28 (0.62) | 0.25 (0.47) | 0.27 (0.44) |
| Intersection density (/mi2) | 119.9 (122.5) | 60.6 (80.6) | 17.5 (44.1) | 39.8 (76.9) |
| Transit stop coveragea | 0.23 (0.38) | 0.03 (0.11) | 0 (0.01) | 0 (0.03) |
| Count of Open park | 1.56 (1.89) | 2.60 (3.01) | 3.18 (4.43) | 1.34 (2.29) |
| Green spacec | 0.09 (0.12) | 0.32 (0.19) | 0.46 (0.24) | 0.52 (0.29) |
| CO (ppm) | 0.37 (0.07) | 0.32 (0.04) | 0.29 (0.05) | 0.27 (0.06) |
| NO2 (ppb) | 14.58 (5.48) | 9.04 (3.39) | 5.70 (1.90) | 4.06 (1.37) |
| O3 (ppb) | 46.32 (5.87) | 45.57 (6.89) | 45.79 (5.94) | 45.61 (5.09) |
| PM 10 (μ/ma) | 20.68 (3.87) | 19.05 (4.06) | 17.19 (4.23) | 16.19 (4.59) |
| PM2.5 (μ/m3) | 10.21 (1.87) | 9.59 (2.10) | 9.02 (2.13) | 8.43 (2.18) |
| SO2 (ppb) | 1.83 (0.73) | 1.53 (0.63) | 1.58 (0.66) | 1.59 (0.59) |
| Rentera | 0.54 (0.23) | 0.35 (0.20) | 0.28 (0.17) | 0.23 (0.11) |
| House pre 1979a | 0.80 (0.21) | 0.59 (0.29) | 0.47 (0.26) | 0.53 (0.18) |
| Crowdinga | 0.07 (0.08) | 0.03 (0.04) | 0.02 (0.03) | 0.02 (0.03) |
| Excessive housing costa | 0.45 (0.12) | 0.36 (0.10) | 0.31 (0.09) | 0.27 (0.08) |
CO, carbon monoxide; NO2, nitrogen dioxide; O3, ozone; PM10, particulate matter smaller than 10 μm; PM2.5, particulate matter smaller than 2.5 μm; ppb, parts per billion; ppm, parts per million; SO2, sulfur dioxide.
a
Proportion per total population.
b
Half mile buffer for high-density urban areas, 1 mile for low-density urban and suburban/small-town areas, and 10 miles for rural areas.
c
Proportion per total land area.