Fig. 2
Percentage increase in cardiovascular disease, coronary heart disease, ischemic stroke, and hypertension hospital admissions per 10-μg/m3 increase in short-term ambient nitrogen dioxide exposure for overall (a) rural and urban counties (b). Note: The results were controlled for risk factors, including daily mean temperature, relative humidity, calendar time, public holidays, and day of the week. A distributed lag model was applied to estimate the county-specific associations, while random effects meta-analyses were used to pool the county-specific associations. Lag 0 corresponded to the present day, lag 1 to the previous day, lag 2 to the day before lag 1, lag 3 to the day before lag 2, and lag 0–1 represented the two-day moving average of the present and previous day