TABLE 4.
Linear associations of childhood exposures to regional and traffic-related air pollutants with diet food patterns identified by principal components analysis of 131 food items included in the food-frequency questionnaires1
| “Fast food” factor score2 | “Sweet food” factor score3 | |||
|---|---|---|---|---|
| β (SE) | P | β (SE) | P | |
| Regional air pollutants | ||||
| NO2 (2 SDs = 12.2 ppb) | 0.16 (0.07) | 0.023 | 0.004 (0.05) | 0.94 |
| NO (2 SDs = 12.4 ppb) | 0.16 (0.06) | 0.012 | −0.03 (0.05) | 0.57 |
| 8-h O3 (2 SDs = 12.1 ppb) | −0.01 (0.07) | 0.93 | 0.03 (0.05) | 0.50 |
| Acid vapor (2 SDs = 3.5 ppb) | 0.15 (0.07) | 0.025 | 0.02 (0.05) | 0.65 |
| PM10 (2 SDs = 14.2 μg/m3) | 0.18 (0.06) | 0.003 | 0.04 (0.05) | 0.34 |
| PM2.5 (2 SDs = 9.6 μg/m3) | 0.20 (0.05) | <0.001 | 0.05 (0.05) | 0.34 |
| EC (2 SDs = 0.45 μg/m3) | 0.17 (0.07) | 0.009 | 0.02 (0.05) | 0.75 |
| OC (2 SDs = 2.7 μg/m3) | 0.17 (0.07) | 0.010 | 0.03 (0.05) | 0.52 |
| Traffic-related air pollutants | ||||
| Freeway NOx (2 SDs = 18.9 ppb) | 0.06 (0.05) | 0.22 | 0.09 (0.05) | 0.09 |
| Non-freeway NOx (2 SDs = 8.8 ppb) | 0.02 (0.06) | 0.77 | 0.08 (0.05) | 0.10 |
| Local street NOx (2 SDs = 8.2 ppb) | 0.05 (0.06) | 0.34 | 0.09 (0.05) | 0.09 |
| Total NOx (2 SDs = 24.2 ppb) | 0.06 (0.05) | 0.24 | 0.11 (0.05) | 0.03 |
Mixed-effects models were used to assess the associations of childhood exposures to regional and traffic-related air pollutants with factor scores of diet food patterns. A random intercept for communities was used to adjust for the design clusters of communities. In addition, age, sex, ethnicity, parental educational levels, household income, number of team sports attended in the last 12 mo, in utero exposure to maternal smoking, second-hand smoke and personal smoking, indoor use of a gas stove at home, frequencies of having dinner prepared away from home, seasons of dietary assessments, and the indicator variable for study cohorts were adjusted for as potential confounders. Wald's test was used to estimate P values for significance based on regression coefficients and SEs. Association effect sizes are presented as regression coefficients: β (SE). Regression coefficients were scaled to 2-SD ranges of each air pollutant exposure. EC, elemental carbon; NO, nitrogen oxide; Non-freeway NOx, the sum of local street NOx and highway-related NOx; NOx, nitrogen oxides; NO2, nitrogen dioxide; OC, organic carbon; O3, ozone; PM2.5, particulate matter with aerodynamic diameter <2.5 µm; PM10, particulate matter with aerodynamic diameter <10 µm; ppb, parts per billion; Total NOx, the sum of non-freeway NOx and freeway NOx.
The “Fast food” factor is represented by frequent consumption of soda, cheeseburger, hamburger, pizza, tacos and burritos, chicken nuggets, and hotdogs.
The “Sweet food” factor is represented by frequent consumption of cakes, snack cakes, sweet rolls, pastries, donuts, cookies, brownies, pies, chocolate, and candy bars.