For cardiovascular disease-related outcomes, the only previous Chinese cohort (n=36 948) other than CKB reported more extreme HRs of 1·56 (95% CI 1·48–1·64) for total cardiovascular disease (4428 cases), 1·52 (1·42–1·63) for hypertension (2448 cases), and 1·66 (1·49–1·87) for stroke (1044 cases) per 10 μg/m3 higher annual ambient NO2 exposure.5 Here, CKB is linked to Stroke.