Distributed lag non-linear model analysis on influence of meteorological factors and air pollutants on death from circulatory system diseases in Ningbo, China

Objective  To analyze the impact of meteorological factors and air pollutants on the mortality of circulatory system diseases in Ningbo, China.

Methods  Descriptive statistics were used to describe the data of meteorological factors and air pollutants, and the daily death toll of circulatory system diseases in Ningbo from 2014 to 2018. A distributed lag nonlinear model was used to explore the relationship between meteorological factors and air pollutants and the average daily death toll from circulatory system diseases.

Results  Both temperature and air pollutants could affect the mortality of circulatory system diseases in the population. The maximum increase of mortality risk was 21.22% (95%CI: 3.84%, 41.52%) at a lag of 0-4 days(lag0-4) at extremely high temperature. The increase of mortality risk of circulatory system diseases was the highest at the extremely low temperature lag2-7 days, with the largest cumulative increase mortality risk of 13.02% (95%CI: 0.99%, 26.48%). The increases of PM₁₀, PM_2.5, and SO₂ concentrations would raise the mortality risk of circulatory system diseases.

Conclusion  Meteorological factors and air pollutants can affect the mortality of circulatory system diseases in residents in Ningbo. Protection awareness should be raised in the case of extreme weather and severe air pollution days. When the daily average temperature is at low or high, it is suggested that the residents should reduce outdoor activities, and take protective measures.