Table 1.
Characteristics of census-derived population based on distance from an oil refinery, 2010-2014
| Characteristics | Total population No. (%) |
Distance from oil refineriesa |
||
|---|---|---|---|---|
| 0-10 miles No. (%) |
11-20 miles No. (%) |
21-30 miles No. (%) |
||
| Total population | 6 302 265 (100) | 2 213 854 (100) | 2 433 988 (100) | 1 654 423 (100) |
| Age group, y | ||||
| 20-39 | 2 587 041 (41.0) | 923 875 (41.7) | 1 022 437 (42.0) | 640 729 (38.7) |
| 40-59 | 2 341 663 (37.2) | 793 942 (35.9) | 890 541 (36.6) | 657 180 (39.7) |
| ≥60 | 1 373 329 (21.8) | 496 037 (22.4) | 520 999 (21.4) | 356 293 (21.5) |
| Sex | ||||
| Male | 3 087 292 (49.0) | 1 089 118 (49.2) | 1188 656 (48.8) | 809 518 (48.9) |
| Female | 3 214 740 (51.0) | 1 124 736 (50.8) | 1 245 321 (51.2) | 844 683 (51.1) |
| Race and ethnicity | ||||
| White | 4 388 769 (69.6) | 1 512 062 (68.3) | 1 698 916 (69.8) | 1 177 791 (71.2) |
| Black | 931 189 (14.8) | 376 355 (17.0) | 348 059 (14.3) | 206 775 (12.5) |
| Other | 982 074 (15.6) | 325 437 (14.7) | 387 002 (15.9) | 269 635 (16.3) |
| Median household income (quartile) | ||||
| $0-$37 506 | 1 139 376 (18.1) | 669 563 (30.2) | 445 355 (18.3) | 24 458 (1.5) |
| $37 507-$46 911 | 1 508 694 (23.9) | 662 308 (29.9) | 554 752 (22.8) | 291 634 (17.6) |
| $46 912-$60 026 | 1 210 634 (19.2) | 324 693 (14.7) | 603 323 (24.8) | 282 618 (17.1) |
| >$60 026 | 2 443 330 (38.8) | 557 291 (25.2) | 830 548 (34.1) | 1 055 491 (63.8) |
| Smoke | 6 302 265 (100) | 323 223 (14.6) | 338 324 (13.9) | 233 274 (14.1) |
| High school diploma or higher education (quartile) | ||||
| 0-79.7 | 2 384 283 (37.8) | 1 152 421 (52.0) | 849 689 (34.9) | 382 174 (23.1) |
| 79.8-87.3 | 1 271 417 (20.2) | 498 682 (22.5) | 344 686 (14.2) | 428 049 (25.9) |
| 87.4-92.5 | 1 175 725 (18.7) | 262 468 (11.9) | 691 563 (28.4) | 221 694 (13.4) |
| >92.5 | 1 470 607 (23.3) | 300 283 (13.6) | 548 039 (22.5) | 622 285 (37.6) |
| Pollution PM2.5, mean (SD)b | 6 302 265 (100) | 9.4 (0.3) | 9.3 (0.4) | 9.3 (0.5) |
| No. of oil wells, mean (SD) | 6 302 265 (100) | 1570.0 (1421.8) | 1933.0 (1518.2) | 1424.6 (1295.9) |
a
We used ArcGIS software (ESRI, Redlands, CA) to compute the linear distance (also known as “as the crow flies”) from the center of the residence zip code of each study subject to the center of the zip code of the nearest oil refinery identified during the study period.
b
Atmospheric particulate matter (PM2.5) level measures high averages of fine particulates (particles 2.5 micrometers or less in size in micrograms per cubic meter) from the air taken as an average level in each county from 1998 when levels were first recorded to 2017.