Table 1.
Descriptive Statistics for Study Variables: Tracts & Counties.
| Tract-Level Descriptive Statistics (N = 64,524) | Mean | Std. Dev. | Percentiles | ||||
|---|---|---|---|---|---|---|---|
| 5th | 25th | 50th | 75th | 99th | |||
| Population Size of Tracts’ Host County [000s] | 1,049.71 | 1,906.97 | 16.87 | 95.79 | 401.61 | 1,003.16 | 9,937.74 |
| Density per Sq Mile Census Tract | 5,215.51 | 11,997.51 | 17.04 | 234.18 | 1,981.92 | 5,204.29 | 61,564.29 |
| Townsend Index-Tract | (0.00) | 3.08 | (3.06) | (2.11) | (0.99) | 1.14 | 10.90 |
| Number Employed in County, 2005 [000s] | 436.19 | 763.05 | 3.78 | 32.03 | 163.77 | 473.59 | 3,805.77 |
| Aggregate Wage Payroll (2005) [$000] | 19,016 | 34,796 | 97 | 955 | 5,861 | 18,893 | 162,202 |
| Avg. Wages per Employee in County 2005 [$000] | 36.05 | 9.42 | 23.51 | 29.26 | 34.97 | 40.81 | 66.37 |
| County-Level Descriptive Statistics (N = 3,138) | Mean | Std. Dev. | 5th | 25th | 50th | 75th | 99th |
| Population Size of Tracts’ Host County [000s] | 934.99 | 3,047.51 | 29.95 | 112.28 | 251.11 | 636.22 | 11,745.13 |
| Number Employed in County, 2005 [000s] | 364.03 | 1,330.98 | 4.77 | 21.69 | 65.36 | 195.73 | 5,507.85 |
| Aggregate Wage Payroll (2005) [$000] | 14,063 | 64,340 | 104 | 524 | 1,728 | 5,784 | 233,483 |
| Avg. Wages per Employee in County, 2005 [$000] | 27.71 | 6.90 | 19.26 | 23.44 | 26.64 | 30.63 | 50.26 |
| Tract-Level Outcomes: | Mean | Std. Dev. | 5th | 25th | 50th | 75th | 99th |
| Respiratory Health Hazard (2005) | 2.30 | 1.96 | 0.44 | 0.96 | 1.80 | 2.99 | 9.87 |
| Neurological Health Hazard (2005) | 0.07 | 0.10 | 0.02 | 0.03 | 0.05 | 0.08 | 0.32 |
| Cancer Risks per MM Population (2005) | 50.11 | 24.38 | 21.32 | 33.89 | 45.39 | 59.56 | 135.79 |