| Overall population | PM2.5 < 35 μg/m3 | PM2.5 ≥ 35 μg/m3 | P |
---|---|---|---|---|
N, n (%)a | 19,236 (100) | 10,010 (52.0) | 9226 (48.0) | Â |
Age, mean ± SDb | 42.8 ± 16.1 | 41.8 ± 15.1 | 43.9 ± 17.1 | < 0.001 |
Age ≥ 65 years old, n (%)a | 2102 (10.9) | 848 (8.5) | 1254 (13.6) | < 0.001 |
Sex (Male), n (%)a | 9041 (47.0) | 4530 (45.3) | 4511 (48.9) | < 0.001 |
Education, n (%)a |  |  |  | < 0.001 |
 Preliminary school or below | 4263 (22.2) | 3098 (31.0) | 1165 (12.6) |  |
 Middle school | 3709 (19.3) | 2032 (20.3) | 1677 (18.2) |  |
 High School | 4245 (22.1) | 1975 (19.7) | 2270 (24.6) |  |
 College or above | 7019 (36.5) | 2905 (29.0) | 4114 (44.6) |  |
Ethnicity, n (%)a |  |  |  | < 0.001 |
 Han | 12,108 (62.9) | 5419 (54.1) | 6689 (72.5) |  |
 Yi | 1981 (10.3) | 1972 (19.7) | 9 (0.1) |  |
 Hui | 1492 (7.8) | 139 (1.4) | 1353 (14.7) |  |
 Mongolian | 1065 (5.5) | 1051 (10.5) | 14 (0.2) |  |
 Tibetan | 664 (3.5) | 657 (6.6) | 7 (0.1) |  |
 Korean | 643 (3.3) | 554 (5.5) | 89 (1.0) |  |
 Tujia | 616 (3.2) | 5 (0.0) | 611 (6.6) |  |
 Miao | 377 (2.0) | 11 (0.1) | 366 (4.0) |  |
 Others | 290 (1.5) | 202 (2.0) | 88 (1.0) |  |
Current smoker, n (%)a | 4064 (21.1) | 2243 (22.4) | 1821 (19.7) | < 0.001 |
Current drinker, n (%)a | 4443 (23.1) | 2399 (24.0) | 2044 (22.2) | 0.003 |
Physical activity, n (%)a |  |  |  | < 0.001 |
 Low | 2679 (13.9) | 1322 (13.2) | 1357 (14.7) |  |
 Moderate | 10,350 (53.8) | 5230 (52.2) | 5120 (55.5) |  |
 High | 6207 (32.3) | 3458 (34.5) | 2749 (29.8) |  |
Sugar-rich diet, n (%)a | 2498 (13.0) | 1411 (14.1) | 1087 (11.8) | < 0.001 |
Salt-rich diet, n (%)a | 2059 (10.7) | 1100 (11.0) | 959 (10.4) | 0.183 |
Spicy diet, n (%)a | 4226 (22.0) | 2073 (20.7) | 2153 (23.3) | < 0.001 |
Fat-rich diet, n (%)a | 1735 (9.0) | 987 (9.9) | 748 (8.1) | < 0.001 |
Light diet, n (%)a | 3594 (18.7) | 1616 (16.1) | 1978 (21.4) | < 0.001 |
Residence (urban), n (%)a | 9777 (50.8) | 4369 (43.6) | 5408 (58.6) | < 0.001 |
Region (south), n (%)a | 10,224 (53.2) | 4942 (49.4) | 5282 (57.3) | < 0.001 |
PM2.5, median (IQR), μg/m3 c | 33.4 (14.8–53.4) | 14.8 (13.8–21.8) | 53.4 (48.9–62.8) | < 0.001 |
Diabetes, n (%)a | 755 (3.9) | 329 (3.3) | 426 (4.6) | < 0.001 |
Hypertension, n (%)a | 4383 (22.8) | 2204 (22.0) | 2179 (23.6) | 0.008 |
Hyperlipidemia, n (%)a | 5391 (28.0) | 3193 (31.9) | 2198 (23.8) | < 0.001 |
Overweight, n (%)a | 7727 (40.2) | 4030 (40.3) | 3697 (40.1) | 0.790 |