Table 2.

Association between air pollution and breast cancer among the 22,877 nurses from DNC

Model 1aModel 2bModel 3c
UnitHR (95% CI)HR (95% CI)HR (95% CI)
3-year mean
PM2.53.3 μg/m31.03 (0.94–1.13)1.02 (0.93–1.12)1.00 (0.91–1.09)
PM102.9 μg/m31.04 (0.95–1.14)1.03 (0.95–1.12)1.02 (0.94–1.11)
NO27.4 μg/m31.03 (0.97–1.10)1.02 (0.96–1.08)1.00 (0.94–1.07)
  • aAdjusted for age.

  • bModel 1 additionally adjusted for smoking (status and intensity), alcohol use, BMI, and physical activity.

  • cModel 3 also adjusted for parity, age at first birth, age at menarche, hormone therapy use, oral contraceptive use, and menopausal status.