Table 2.
Main characteristics of preschool children with different BLLs.
| Characteristics | BLLs (μg/L) | F (p value) | BLL group |
χ
2 (p value) |
|||
|---|---|---|---|---|---|---|---|
| <50 (μg/L) | 50–<100 (μg/L) | ≥100 (μg/L) | |||||
| Mean ± SD | Geometric mean | N (%) | N (%) | N (%) | |||
| Sex | |||||||
| Male | 59.7 ± 41.2 | 51.5 | 25.94 (<0.0001) |
571 (52.5) | 396 (36.4) | 120 (11.1) | 19.71 (<0.0001) |
| Female | 52.6 ± 34.6 | 46.0 | 561 (60.3) | 312 (33.5) | 58 (6.2) | ||
| Age (years) | |||||||
| <3 | 54.8 ± 57.2 | 44.7 | 2.88 (0.0215) |
41 (62.1) | 21 (31.8) | 4 (6.1) | 20.80 (0.0077) |
| 3 to <4 | 62.8 ± 51.1 | 51.8 | 157 (53.4) | 97 (33.0) | 40 (13.6) | ||
| 4 to <5 | 56.9 ± 32.9 | 50.3 | 312 (51.7) | 244 (40.4) | 48 (7.9) | ||
| 5 to <6 | 54.3 ± 36.7 | 47.2 | 397 (59.3) | 218 (32.5) | 55 (8.2) | ||
| ≥6 | 54.8 ± 33.5 | 48.1 | 225 (58.6) | 128 (33.3) | 31 (8.1) | ||
| Residence | |||||||
| Outlander | 57.7 ± 32.9 | 50.9 | 8.06 (0.0046) |
387 (50.6) | 310 (40.5) | 68 (8.9) | 17.05 (0.0002) |
| Native | 55.7 ± 41.4 | 47.7 | 745 (59.5) | 398 (31.8) | 110 (8.7) | ||
| Town | |||||||
| Fengjiang | 54.8 ± 30.4 | 48.6 | 0.53 (0.4653) |
692 (54.8) | 471 (37.3) | 101 (7.9) | 8.32 (0.0156) |
| Pengjie | 59.2 ± 48.9 | 49.4 | 440 (58.4) | 237 (31.4) | 77 (10.2) | ||
| Father's education | |||||||
| Primary school | 60.0 ± 35.0 | 53.0∗ | 19.45 (0.0005) |
286 (48.9) | 237 (40.5) | 62 (10.6) | 26.58 (<0.0001) |
| Middle and high school | 55.75 ± 40.27 | 48.0∗ | 774 (58.0) | 449 (33.6) | 112 (8.4) | ||
| College or higher | 44.4 ± 28.2 | 38.8∗ | 72 (73.5) | 22 (22.5) | 4 (4.0) | ||
| Father's occupation | |||||||
| Lead related | 59.0 ± 40.7 | 50.9 | 14.04 (0.0002) |
545 (52.8) | 387 (37.5) | 101 (9.7) | 9.81 (0.0074) |
| Not lead-related | 53.8 ± 35.6 | 46.8 | 587 (59.6) | 321 (32.6) | 77 (7.8) | ||
| Mother's education | |||||||
| Primary school | 60.3 ± 36.7 | 52.6∗ | 22.35 (<0.0001) |
346 (48.8) | 281 (39.6) | 82 (11.6) | 40.13 (<0.0001) |
| Middle and high school | 55.3 ± 39.9 | 47.9∗ | 700 (58.5) | 406 (33.9) | 91 (7.6) | ||
| College or higher | 44.1 ± 29.5 | 38.2∗ | 86 (76.8) | 21 (18.8) | 5 (4.4) | ||
| Mother's occupation | |||||||
| Lead-related | 59.5 ± 43.4 | 51.1 | 13.24 (0.0003) |
486 (52.5) | 347 (37.5) | 93 (10.0) | 9.66 (0.0080) |
| Not lead-related | 53.8 ± 33.4 | 47.1 | 646 (59.2) | 361 (33.2) | 85 (7.6) | ||
| Care giver's education | |||||||
| Primary school | 57.8 ± 34.4 | 50.8# | 8.77 (0.0002) |
452 (51.5) | 341 (38.9) | 84 (9.6) | 21.46 (0.0003) |
| Middle and high school | 56.0 ± 41.8 | 48.1∗ | 616 (58.4) | 350 (33.2) | 89 (8.4) | ||
| College or higher | 47.4 ± 32.8 | 40.8∗# | 64 (74.4) | 17 (19.8) | 5 (5.8) | ||
| Yearly household income (RMB) | |||||||
| <10000 | 58.5 ± 43.0 | 50.2 | 2.74 (0.0649) |
365 (53.8) | 255 (37.6) | 59 (8.7) | 8.19 (0.0847) |
| 10000–15000 | 55.8 ± 35.4 | 48.9 | 542 (55.5) | 348 (35.6) | 87 (8.9) | ||
| >15000 | 54.3 ± 37.1 | 46.5 | 225 (62.2) | 105 (29.0) | 32 (8.8) | ||
| Residential floor | |||||||
| 1st floor | 60.5 ± 35.9 | 53.1∗ | 13.2 (<0.0001) |
300 (47.8) | 258 (41.1) | 70 (11.1) | 35.12 (<0.0001) |
| 2nd to 3rd floor | 56.4 ± 42.1 | 48.2∗ | 641 (58.3) | 362 (32.9) | 96 (8.7) | ||
| 4th to 6th floor | 48.3 ± 25.9 | 43.1∗ | 181 (65.6) | 83 (30.1) | 12 (4.3) | ||
| >6th floor | 39.3 ± 11.1 | 37.7∗ | 10 (71.4) | 4 (28.6) | 0 (0) | ||
| Family-style small factory | |||||||
| No | 56.6 ± 37.9 | 49.2 | 0.57 (0.4512) |
749 (54.9) | 493 (36.2) | 121 (8.9) | 1.19 (0.2334) |
| Yes | 56.2 ± 39.5 | 48.3 | 383 (58.5) | 215 (32.8) | 57 (8.7) | ||
| Passive smoking | |||||||
| Never | 58.9 ± 42.7 | 50.1 | 2.14 (0.0927) |
416 (54.0) | 277 (36.0) | 77 (10.0) | 5.872 (0.4376) |
| Once in a while | 54.2 ± 36.1 | 47.4 | 522 (58.7) | 299 (33.6) | 68 (7.7) | ||
| Often | 57.2 ± 34.3 | 50.3 | 172 (53.6) | 119 (37.1) | 30 (9.4) | ||
| Always | 53.3 ± 27.8 | 47.3 | 22 (57.9) | 13 (34.2) | 3 (7.9) | ||
| Use of decorative tableware | |||||||
| Never | 50.3 ± 30.5 | 50.6∗ | 4.47 (0.0039) |
97 (63.4) | 48 (31.4) | 8 (5.2) | 17.36 (0.0081) |
| Sometimes | 52.9 ± 37.2 | 49.0 | 236 (58.4) | 146 (36.1) | 22 (5.5) | ||
| Half of the time | 55.7 ± 33.4 | 46.4∗ | 304 (55.6) | 198 (36.2) | 45 (8.2) | ||
| Always | 59.5 ± 42.5 | 44.9∗ | 495 (54.2) | 316 (34.6) | 103 (11.2) | ||
| Drinking water | |||||||
| Tap water | 56.7 ± 39.3 | 48.9 | 0.70 (0.5529) |
1047 (56.3) | 648 (34.9) | 164 (8.8) | 2.38 (0.8815) |
| Ground water | 55.0 ± 24.5 | 50.9 | 18 (54.5) | 13 (39.4) | 2 (6.1) | ||
| Surface water | 59.5 ± 31.3 | 53.7 | 13 (44.8) | 12 (41.4) | 4 (13.8) | ||
| Pure water | 51.5 ± 24.9 | 46.6 | 54 (55.7) | 35 (36.1) | 8 (8.2) | ||
| Factory around the house or residential building | |||||||
| Yes | 58.4 ± 42.1 | 50.1 | 7.25 (0.0071) |
670 (54.7) | 435 (35.5) | 121 (9.8) | 5.20 (0.0742) |
| No | 53.4 ± 31.6 | 47.1 | 462 (58.3) | 273 (34.5) | 57 (7.2) | ||
∗, # p < 0.05 tested by Bonferroni for multiple comparison between any two groups in a variable.