Table 1.
Air pollution means ± standard errors according to participant characteristics.
| Characteristic | Overall n (%) |
PM2.5 a,b | Distance to Road c | Traffic d | Black Carbon b |
|---|---|---|---|---|---|
| (n = 463) | (n = 322) | n = 461 | n = 459 | n = 455 | |
| Mother | |||||
| Household income ≤ $40,000/year | |||||
| No | 363 (78) | 12.1 ± 0.1 | 1107.7 ± 1.1 | 498.8 ± 1.1 | 0.69 ± 0.01 |
| Yes | 54 (12) | 12.3 ± 0.1 | 742.5 ± 1.2 | 1056.0 ± 1.2 | 0.80 ± 0.03 |
| Education ≤ high school | |||||
| No | 415 (90) | 12.0 ± 0.1 | 1074.9 ± 1.1 | 508.9 ± 1.1 | 0.69 ± 0.01 |
| Yes | 46 (10) | 12.1 ± 0.1 | 820.6 ± 1.3 | 1144.0 ± 1.2 | 0.81 ± 0.03 |
| Race/ethnicity | |||||
| Black | 62 (13) | 12.1 ± 0.1 | 544.6 ± 1.2 | 927.3 ± 1.1 | 0.82 ± 0.02 |
| Hispanic | 27 (6) | 12.2 ± 0.2 | 871.3 ± 1.4 | 686.9 ± 2.1 | 0.85 ± 0.03 |
| Other | 43 (9) | 12.0 ± 0.1 | 862.6 ± 1.2 | 766.8 ± 1.2 | 0.75 ± 0.03 |
| White | 329 (71) | 12.0 ± 0.1 | 1236.5 ± 1.1 | 469.8 ± 1.2 | 0.67 ± 0.01 |
| Pre-pregnancy BMI, kg/m2 | |||||
| Underweight, <18.5 | 19 (4) | 12.4 ± 0.3 | 614.0 ± 1.4 | 946.0 ± 1.2 | 0.76 ± 0.05 |
| Healthy weight, 18.5−<25 | 275 (59) | 12.1 ± 0.1 | 1053.6 ± 1.1 | 469.8 ± 1.2 | 0.69 ± 0.01 |
| Overweight, 25−<30 | 98 (21) | 11.9 ± 0.1 | 1339.4 ± 1.1 | 634.1 ± 1.2 | 0.71 ± 0.02 |
| Obese, >30 | 69 (15) | 12.2 ± 0.1 | 845.6 ± 1.2 | 766.8 ± 1.2 | 0.75 ± 0.03 |
| Age < 23 years | |||||
| No | 436 (94) | 12.0 ± 0.1 | 1074.9 ± 1.1 | 535.0 ± 1.1 | 0.70 ± 0.01 |
| Yes | 27 (6) | 12.3 ± 0.2 | 706.3 ± 1.3 | 974.8 ± 1.3 | 0.81 ± 0.04 |
| Pregnancy smoking status | |||||
| never | 322 (70) | 12.1 ± 0.1 | 1022.5 ± 1.1 | 503.8 ± 1.2 | 0.70 ± 0.01 |
| former | 82 (18) | 11.9 ± 0.1 | 1141.4 ± 1.2 | 579.5 ± 1.2 | 0.67 ± 0.02 |
| pregnancy | 54 (12) | 12.2 ± 0.1 | 1043.1 ± 1.2 | 899.9 ± 1.2 | 0.77 ± 0.04 |
| Cesarean delivery | |||||
| No | 370 (80) | 12.1 ± 0.1 | 1053.6 ± 1.1 | 573.8 ± 1.1 | 0.71 ± 0.01 |
| Yes | 87 (19) | 12.0 ± 0.1 | 1096.6 ± 1.2 | 438.0 ± 1.3 | 0.67 ± 0.02 |
| Probable depression in pregnancy | |||||
| No | 308 (67) | 12.1 ± 0.8 | 1152.9 ± 3.5 | 455.9 ± 14.6 | 0.68 ± 0.21 |
| Yes | 53 (11) | 12.0 ± 0.7 | 1074.9 ± 3.6 | 766.8 ± 4.0 | 0.76 ± 0.26 |
| Ever depressed | |||||
| No | 281 (61) | 12.1 ± 0.1 | 1152.9 ± 1.1 | 433.7 ± 1.2 | 0.68 ± 0.01 |
| Yes | 80 (17) | 12.1 ± 0.1 | 1096.6 ± 1.2 | 782.3 ± 1.2 | 0.75 ± 0.03 |
| Child | |||||
| Season of birth | |||||
| Winter | 116 (25) | 11.7 ± 0.1 | 1043.1 ± 1.1 | 420.8 ± 1.3 | 0.73 ± 0.02 |
| Spring | 118 (25) | 12.1 ± 0.1 | 1224.1 ± 1.1 | 474.5 ± 1.3 | 0.73 ± 0.02 |
| Summer | 123 (27) | 12.3 ± 0.1 | 1074.9 ± 1.1 | 615.4 ± 1.2 | 0.70 ± 0.02 |
| Fall | 106 (23) | 12.2 ± 0.1 | 862.6 ± 1.2 | 798.1 ± 1.2 | 0.65 ± 0.02 |
| Child sex | |||||
| Male | 253 (55) | 12.0 ± 0.1 | 1043.1 ± 1.1 | 603.2 ± 1.1 | 0.72 ± 0.01 |
| Female | 210 (45) | 12.1 ± 0.1 | 1053.6 ± 1.1 | 503.8 ± 1.2 | 0.69 ± 0.01 |
a PM2.5: particulate matter < 2.5 microns; b Calculated by averaging daily concentrations (pg/mL) for each individual over the prenatal period, calculated as the date of last menstrual period through the day before birth; c Measured as shortest distance in meters between the geocoded location of the mother’s reported residential address and a primary major roadway (US Census feature class A1 or A2); d Measured as the length of all roads (km) within 100 m of mother’s residence, multiplied by the traffic counts on those roads (vehicles/day); Bold: mean exposure differs by level of characteristic at p < 0.05; italics: mean exposure differs at p < 0.10 (ANOVA for categorical variables, chi-square for dichotomous variables).