Fig. 4From: Altered deposition of inhaled nanoparticles in subjects with chronic obstructive pulmonary disease(a, b). Correlations for volumetric sample depth and particle size. The relation between lung particle deposition measured at different sample depths and for different particle sizes. In a (left panel), for 50 nm particles at sample depths 1300 ml and 1800 ml, and in b (right panel), for 50 nm and 100 nm particles at sample depth 1800 ml. Pearson’s correlation coefficient and p-values are indicated in the figure. Healthy = green, smokers = blue, COPD = redBack to article page