Table 2.
Characteristics of children from the PARIS cohort included in the study according to median level of traffic-related air pollution exposure during the first year (n = 2,015).
| Characteristicsa | NOx < 75 μg/m3 (n = 973) | NOx ≥ 75 μg/m3 (n = 1,042) | p-Value |
|---|---|---|---|
| Sex | 0.84 | ||
| Male | 496 (51.0) | 536 (51.4) | |
| Female | 477 (49.0) | 506 (48.6) | |
| Birth weight | 3.42 ± 0.39 | 3.39 ± 0.40 | 0.12 |
| Family socioeconomic status | 0.01 | ||
| Low | 69 (7.1) | 53 (5.1) | |
| Medium | 274 (28.2) | 251 (24.1) | |
| High | 630 (64.7) | 738 (70.8) | |
| Maternal education | 0.58 | ||
| High school education or less | 109 (11.2) | 109 (10.5) | |
| At least some college | 862 (88.8) | 933 (89.5) | |
| Missing (n) | 2 | 0 | |
| Maternal history of asthma, eczema, or allergic rhinitis | 0.56 | ||
| No | 600 (61.7) | 655 (62.9) | |
| Yes | 373 (38.3) | 386 (37.1) | |
| Missing (n) | 0 | 1 | |
| Paternal history of asthma, eczema, or allergic rhinitis | 0.72 | ||
| No | 606 (62.5) | 656 (63.3) | |
| Yes | 364 (37.5) | 381 (36.7) | |
| Missing (n) | 3 | 5 | |
| Maternal smoking during pregnancy | 0.04 | ||
| No | 889 (91.4) | 923 (88.6) | |
| Yes | 84 (8.6) | 119 (11.4) | |
| Visible mold in the home | 0.92 | ||
| No | 822 (84.6) | 877 (84.4) | |
| Yes | 150 (15.4) | 162 (15.6) | |
| Missing (n) | 1 | 3 | |
| Use of gas for cooking or heating in the home | 0.003 | ||
| No | 455 (48.0) | 425 (41.3) | |
| Yes | 493 (52.0) | 603 (58.7) | |
| Missing (n) | 25 | 14 | |
| Exclusive breastfeeding during the first 3 months | 0.65 | ||
| No | 678 (70.2) | 736 (71.1) | |
| Yes | 288 (29.8) | 299 (28.9) | |
| Missing (n) | 7 | 7 | |
| Day care during the first 6 months | 0.87 | ||
| No | 374 (39.8) | 379 (38.4) | |
| Yes, at home | 158 (16.8) | 174 (17.6) | |
| Yes, at a childminder’s home | 208 (22.1) | 229 (23.2) | |
| Yes, in a day care center | 200 (21.3) | 206 (20.8) | |
| Yes, but type not specified (n) | 33 | 54 | |
| Exposure to smoking at home during the first year | 0.13 | ||
| No | 717 (75.3) | 735 (72.3) | |
| Yes | 235 (24.7) | 282 (27.7) | |
| Missing (n) | 21 | 25 | |
| Stressful family events during the first 2 yearsb | 0.51 | ||
| No | 521 (54.8) | 540 (53.3) | |
| Yes | 430 (45.2) | 473 (46.7) | |
| Missing (n) | 22 | 29 | |
| Body mass index ≥ 85th percentile for age and sex at 2–3 years | 0.06 | ||
| No | 755 (79.5) | 770 (75.9) | |
| Yes | 195 (20.5) | 245 (24.1) | |
| Missing (n) | 23 | 27 | |
| Data are shown as n (%) or mean ± SD. aCharacteristics are at birth unless otherwise specified. bAmong parental separation/divorce, parental loss of job, serious health problem, or death of a family member or close relative. | |||