Objective To explore the impact of short-term exposure to atmospheric nitrogen dioxide (NO₂) on cardiovascular emergency visits in Tianjin, China.

Methods Data of Tianjin from 2015 to 2022 were collected, including air quality, meteorological conditions, and emergency visits. A generalized linear model based on Poisson regression was used for the analysis of the relationship between atmospheric NO₂ exposure and cardiovascular emergency visits.

Results A total of 107 179 cardiovascular emergency visits were recorded between 2015 and 2022. Each 10 μg/m³ increase in the daily average concentration of NO₂ was associated with a 1.11% increase in cardiovascular emergency visits (95% confidence interval: 0.42%-1.82%), and there was a cumulative lag effect. Stratified analysis by sex showed that atmospheric NO₂ had a significant impact on cardiovascular emergency visits among females, also demonstrating a cumulative lag effect, but had an insignificant impact on males. Stratified analysis by age showed that atmospheric NO₂ influenced cardiovascular emergency visits in both populations under 65 years of age and those aged 65 or older, and there was a cumulative lag effect. The impact was more pronounced in the population aged 65 or older.

Conclusion The increase in atmospheric NO₂ is associated with the increase in cardiovascular emergency visits, and there is a cumulative lag effect, especially for the female and the elderly.