Objective

Air pollution is considered one of the most important risk factors for ischemic heart disease (IHD), which is a major public health concern. The disease burden of IHD has continued to rise in China in the past two decades. However, epidemiological studies examining the associations between air pollution and IHD have been scarce in China, and the only studies were conducted in severe air pollution areas, where air pollution levels seriously exceed the World Health Organization Air Quality Guidelines. Whether the influence of air pollution on IHD in areas with relatively low levels of air pollution differs from the influence of high pollution levels in heavily studied areas was unknown until now. Furthermore, the estimation of the disease burden of IHD related to air pollution has been very limited.

Methods

We conducted a time-series study to estimate the short-term burden of ambient air pollution on IHD using the indicator of years of life lost (YLL), based on 10 322 IHD deaths from 2011 to 2015 in Ningbo, a coastal city in South China.

Results

The mean concentrations of fine particle (PM_2.5), sulfur dioxide (SO₂) and nitrogen dioxide (NO₂) were 49.58 μg/m³, 21.34 μg/m³ and 43.41 μg/m³, respectively. A 10 μg/m³ increase in PM_2.5, SO₂ and NO₂ was associated with changes in YLL of 0.71 (95%CI: − 0.21,1.64), 3.31 (95%CI: 0.78, 5.84), and 2.27 (95%CI: 0.26, 4.28) years, respectively. Relatively stronger impacts were found for gaseous pollutants than PM_2.5. A larger increase in YLL was found in the younger population than in the older population for NO₂ exposure. In addition, estimations of the effects of SO₂ and NO₂ on YLL were higher for males than females. SO₂ exposure was positively associated with YLL in widowed group.

Conclusions

The findings highlighted the importance of stringent air pollution control, especially for gaseous pollutants. Furthermore, using the indicator of YLL, considering the occurrence of death at different ages, provided more information for resource allocation and protection of vulnerable populations.