Table 2 Estimated differences^a (95% confidence interval) in square-root-transformed percent mammographic density for a 10-μg/m³ PM increase

 1 year prior

n = 1624

n = 577

n = 554

n = 261

n = 232

  PM_2.5

0.04 (–0.17, 0.26)

0.06 (–0.40, 0.52)

–0.08 (–0.58, 0.43)

0 (–0.35, 0.34)

0.21 (–0.32, 0.74)

0.59

  PM_2.5–10

–0.01 (–0.16, 0.15)

–0.01 (–0.57, 0.54)

–0.07 (–0.42, 0.28)

0.08 (–0.19, 0.34)

–0.34 (–0.95, 0.27)

0.45

  PM₁₀

0.01 (–0.10, 0.12)

0.02 (–0.26, 0.30)

–0.06 (–0.33, 0.20)

0.03 (–0.14, 0.20)

–0.05 (–0.57, 0.47)

0.58

 3-year average

n = 1624

n = 582

n = 554

n = 260

n = 228

  PM_2.5

0.05 (–0.16, 0.27)

0.05 (–0.40, 0.51)

–0.05 (–0.55, 0.45)

–0.01 (–0.36, 0.35)

0.27 (–0.27, 0.81)

0.53

  PM_2.5–10

0 (–0.15, 0.16)

0.02 (–0.53, 0.57)

–0.04 (–0.40, 0.33)

0.10 (–0.18, 0.38)

–0.58 (–1.19, 0.03)

0.22

  PM₁₀

0.02 (–0.10, 0.13)

0.02 (–0.25, 0.30)

–0.03 (–0.30, 0.23)

0.04 (–0.13, 0.20)

–0.17 (–0.70, 0.36)

0.67

 1 year prior

n = 1634

n = 738

n = 360

n = 274

n = 262

  PM_2.5

–0.04 (–0.26, 0.19)

0.37 (–0.03, 0.77)

–0.24 (–0.91, 0.42)

–0.21 (–0.56, 0.13)

–0.05 (–0.70, 0.60)

0.09

  PM_2.5–10

–0.01 (–0.16, 0.14)

0.22 (–0.24, 0.69)

0.11 (–0.38, 0.60)

–0.22 (–0.47, 0.03)

0.32 (–0.32, 0.96)

0.29

  PM₁₀

–0.01 (–0.12, 0.10)

0.19 (–0.05, 0.42)

–0.01 (–0.34, 0.32)

–0.14 (–0.29, 0.02)

0.19 (–0.35, 0.74)

0.15

 3-year average

n = 1634

n = 745

n = 364

n = 272

n = 253

  PM_2.5

–0.05 (–0.27, 0.17)

0.39 (–0.02, 0.79)

–0.25 (–0.91, 0.42)

–0.27 (–0.62, 0.07)

0.06 (–0.61, 0.73)

0.06

  PM_2.5–10

–0.01 (–0.16, 0.14)

0.19 (–0.27, 0.65)

0.16 (–0.32, 0.64)

–0.23 (–0.47, 0.02)

0.39 (–0.30, 1.07)

0.24

  PM₁₀

–0.02 (–0.13, 0.09)

0.18 (–0.06, 0.41)

0.02 (–0.31, 0.34)

–0.15 (–0.31, 0.01)

0.31 (–0.26, 0.89)

0.10