Middle-term nitrogen dioxide exposure and electrocardiogram abnormalities: A nationwide longitudinal study

Ecotoxicol Environ Saf. 2023 Nov 1:266:115562. doi: 10.1016/j.ecoenv.2023.115562. Epub 2023 Oct 30.

Abstract

Background: Recently, professionals, such as those from the World Health Organization, have recommended a rigorous standard for nitrogen dioxide (NO2), a typical urban air pollutant affected by regular traffic emissions, based on its short-term and long-term cardiorespiratory effects. However, the association between middle-term NO2 exposure and cardiovascular disorders remains unknown.

Objectives: This study was conducted to examine the relationship between NO2 exposure and its middle-term cardiovascular risks indicated by electrocardiogram (ECG) abnormalities.

Method: We included 61,094 subjects (132,249 visits) with repeated ECG observations based on longitudinal data from the China National Stroke Screening Survey (CNSSS). The NO2 exposure concentration was derived from a predictive model, measured as the monthly average concentration in the 6 months of preceding the ECG measurement. We used the generalized estimation equation to assess the association between NO2 exposure and ECG abnormalities.

Result: For each 10 µg/m3 increase in monthly average NO2 concentration, the odds ratio of ECG abnormalities was 1.10 (95% confidence interval [CI] 1.09-1.12) after multiple adjustments. Stratified regression analyses of urban and rural residents showed associations between middle-term NO2 exposure and ECG abnormalities in urban (OR 1.09 [95% CI 1.08-1.11]) and rural residents (OR 1.14 [95% CI 1.10-1.19]). The association was robust within different subpopulations. Associations generally remained statistically significant (OR 1.03 [95% CI 1.02-1.05]) after extra adjustment for PM2.5. Exposure-response relationship analysis revealed a nearly linear relationship between NO2 exposure and the risk for ECG abnormalities.

Conclusion: Using the variation in ECG signals as a potentially reversible indicator for subclinical risk in cardiovascular systems, our study provides additional evidence on the increased risk posed by middle-term NO2 exposure. Our study showed that policies controlling for NO2 concentrations are beneficial to prevent cardiovascular diseases among Chinese adults.

Keywords: Air pollution; ECG abnormalities; Longitudinal study; Nitrogen dioxide.

MeSH terms

  • Adult
  • Air Pollutants* / analysis
  • Air Pollutants* / toxicity
  • Air Pollution* / analysis
  • Cardiovascular Diseases* / chemically induced
  • Electrocardiography
  • Environmental Exposure / adverse effects
  • Environmental Exposure / analysis
  • Humans
  • Longitudinal Studies
  • Nitrogen Dioxide / analysis
  • Particulate Matter / toxicity

Substances

  • Nitrogen Dioxide
  • Particulate Matter
  • Air Pollutants