Table 4.
Adjusteda associations of distance metrics and pubertal development
| Breast onset |
Pubic hair onset |
||||
|---|---|---|---|---|---|
| Traffic metric | N (%) | TR (95% CI) | Median age of onset | TR (95% CI) | Median age of onset |
| Distance to nearest major road (m) | |||||
| Local traffic (>150 m) | 110 (28.2) | 1.00 | 10.1 years | 1.00 | 10.7 years |
| >100 to ≤ 150 m | 83 (21.3) | 1.02 (0.98, 1.05) | 2.4 months | 0.96 (0.92, 0.99) | −5.1 months |
| >50 to ≤ 100 m | 92 (23.6) | 0.99 (0.96, 1.02) | −1.2 months | 0.95 (0.91, 0.99) | −6.4 months |
| ≤50 m | 105 (26.9) | 0.99 (0.96, 1.02) | −1.2 months | 0.97 (0.94, 1.01) | −3.8 months |
| Distance to road/wind b | |||||
| Local traffic (>150 m) | 110 (28.2) | 1.00 | 10.1 years | 1.00 | 10.7 years |
| ≤150 m upwind | 142 (36.4) | 1.01 (0.98, 1.04) | 1.2 months | 0.96 (0.93, 1.00) | −5.1 months |
| ≤150 m downwind | 138 (35.4) | 0.99 (0.97, 1.02) | −1.2 months | 0.96 (0.93, 0.99) | −5.1 months |
a
Adjusted models are adjusted for race/ethnicity, household income, and girls’ cotinine level.
b
Highways in the area run north/south, prevailing winds in the study area are from the west. Locations east of the freeways are classified as downwind and those west of the freeway are classified as upwind.