Figure 1.

Lifelines and UK Biobank study population flow diagram. Note: ${\text{NO}}_2$, nitrogen dioxide; PM, particulate matter. ¹By the time of this study, home addresses of 82,959 participants had not yet been geocoded by Lifelines data managers ²Residential addresses of 33,934 UK Biobank participants were excluded for all PM measures because they were farther than $400\mathrm{km}$ away from the original European Study of Cohorts for Air Pollution Effects (ESCAPE) monitoring area in southeast England. ³Only 35% of UK Biobank subjects had data for shortness of breath because it was added to the baseline survey late in the recruitment phase (i.e., as of 2009).