Table 4

Ambient air particulate matter levels and hazards for COPD and other pulmonary outcomes

COPD COPD symptoms Other chronic pulmonary diseases
N=521 N=1283 N=696
PM levelsAdjusted OR*95% CIAdjusted OR95% CIAdjusted OR95% CI
 ≤35 µg/m3 1reference1reference1reference
 >35 and ≤75 µg/m3 2.4161.417 to 4.1181.4581.132 to 1.8791.8361.245 to 2.708
 >75 µg/m3 2.5301.280 to 5.0011.2850.888 to 1.8591.8701.142 to 3.062
 ≤50 µg/m3 1reference1reference1reference
 >50 and ≤150 µg/m3 2.4421.449 to 4.1171.4481.129 to 1.8581.9001.291 to 2.797
  • *OR of daily mean PM2.5/10 concentration for COPD, COPD symptoms, other chronic pulmonary diseases, and all models are adjusted for age group, sex, personal education state, smoking history, family history, biofuel and occupational exposure, history of childhood pneumonia in the hospital, mother smoking during pregnancy, maternal exposure to second-hand smoking during pregnancy, kitchen ventilation quality, second-hand smoking exposure, rural/urban distribution and clusters.

  • †PM2.5/10=particulate matter with a median aerodynamic diameter <2.5/10 µm; calculation was based on all participants (n=5993) in the seven clusters.