Table 3:

Importance of pathophysiological features associated with environmental exposure-related causes of chronic obstructive pulmonary disease

	Indoor pollutant exposure	Ambient air pollution or smog	Wildfire smoke	Occupational exposure
Clinical manifestations
Chronic cough	Moderately important	Moderately important	Moderately important	Very important
Sputum production	Moderately important	Moderately important	Mildly important	Moderately important
Dyspnoea	Moderately important	Mildly important	··	Moderately important
Wheezing	Mildly important	Mildly important	··	Moderately important
Exacerbations	Moderately important	Moderately important	Moderately important	Moderately important
Systemic manifestations	Moderately important	Mildly important	··	Mildly important
Airway remodelling and inflammation
Hypertrophy of airway smooth hypertrophy	Very important	··	··	Very important
Thickening of basement membrane	Moderately important	··	··	Moderately important
Eosinophilic inflammation	Moderately important	··	··	Moderately important
Neutrophilic inflammation	Mildly important	Mildly important	Mildly important	··
Pauci immune inflammation	Mildly important	··	··	··
Change in turnover of extracellular matrix	Moderately important	··	··	··
Persistent airflow limitation
FEV1/FVC <0·70	Very important	Moderately important	··	Very important
Ratio of total to effective resistance	Very important	··	··	Very important
Difference in oscillation resistance at 5 Hz and 19 Hz	Very important	Moderately important	··	Very important
Reactance area	Very important	Moderately important	··	Very important
Parenchymal destruction
CT emphysema	Mildly important	Mildly important	··	Moderately important
Decreased DLCO	Mildly important	··	··	Moderately important

FEV₁=forced expiratory volume in 1 s. FVC=forced vital capacity. DLCO=diffusing capacity of the lungs for carbon monoxide.