Table 2.
Odds ratios (ORs) and 95% confidence intervals of term low birthweight by the quartile groups of residential radon levels and exposure windows (n = 68,159).
| OR (95% CI) | |||||||
|---|---|---|---|---|---|---|---|
| Model without adjustment for the correlation across trimesters | Model adjusted for the correlation across trimesters | ||||||
| Pregnancy | Trimester 1 | Trimester 2 | Trimester 3 | Trimester 1 | Trimester 2 | Trimester 3 | |
| Basement radon levels (pCi/L) a | |||||||
| Q1 (<0.81) | Reference | Reference | Reference | Reference | Reference | Reference | Reference |
| Q2 (0.81–0.99) | 1.01 (0.85, 1.21) | 1.07 (0.91, 1.27) | 1.07 (0.91, 1.26) | 1.02 (0.87, 1.21) | 1.13 (0.96, 1.34) | 1.17 (0.99, 1.38) | 0.89 (0.76, 1.05) |
| Q3 (1.00–1.31) | 1.19 (0.99, 1.43) | 1.22 (1.02, 1.45) | 1.21 (1.02, 1.45) | 1.15 (0.96, 1.37) | 1.22 (1.03, 1.44) | 1.12 (0.95, 1.33) | 1.00 (0.85, 1.18) |
| Q4 (≥1.32) | 1.16 (0.97, 1.39) | 1.26 (1.05, 1.50) | 1.16 (0.97, 1.39) | 1.08 (0.90, 1.30) | 1.30 (1.08, 1.55) | 1.02 (0.85, 1.22) | 0.98 (0.82, 1.18) |
| Ground-level radon levels (pCi/L) a | |||||||
| Q1 (<0.46) | Reference | Reference | Reference | Reference | Reference | Reference | Reference |
| Q2 (0.46–0.67) | 1.00 (0.83, 1.20) | 1.03 (0.87, 1.22) | 0.97 (0.81, 1.15) | 1.05 (0.88, 1.25) | 1.07 (0.92, 1.25) | 1.06 (0.90, 1.24) | 1.02 (0.87, 1.19) |
| Q3 (0.68–0.87) | 1.14 (0.95, 1.36) | 1.09 (0.91, 1.30) | 1.03 (0.86, 1.23) | 1.08 (0.90, 1.29) | 0.98 (0.83, 1.15) | 1.02 (0.86, 1.20) | 0.92 (0.78, 1.08) |
| Q4 (≥0.88) | 0.99 (0.81, 1.21) | 1.05 (0.87, 1.27) | 1.07 (0.88, 1.29) | 1.03 (0.85, 1.25) | 1.06 (0.89, 1.27) | 1.01 (0.84, 1.21) | 1.00 (0.83, 1.19) |
Note. Models adjusted for mother’s age, sex of infant, race/ethnicity of infant, Apgar five score, marital status, smoking during pregnancy, alcohol consumption during pregnancy, parity, the season of birth, insurance type, maternal education level, average ambient temperature exposure during pregnancy, gestational diabetes, gestational hypertension, eclampsia, prenatal care, community-level percent Black population, percent of the single-family houses, percent population in poverty, community-level median household income, and urbanicity.
radon exposure levels throughout pregnancy for exposure quartile groups.