Clearing the Air to Address Pollution's Cardiovascular Health Crisis

Abstract

Air pollution is a critical global health issue that significantly impacts cardiovascular health. The air pollutant PM_2.5 (particulate matter with a diameter of 2.5 micrometres or less) has been positioned as a leading environmental risk factor for morbidity and mortality, especially from cardiovascular diseases (CVDs). Using data from the World Health Organization (WHO), Global Health Observatory, and the United Nations Environment Programme, we explored global trends in air pollution, with a focus on PM_2.5 levels, the implications for cardiovascular health, and the policy measures aimed at reducing their impact. Despite progress in reducing pollution levels in high-income countries, global trends show a limited annual reduction in PM_2.5 concentration. The analysis highlights disparities between regions, with low- and middle-income countries bearing the brunt of air pollution-related CVDs. In 2019 alone, ambient air pollution was responsible for approximately 4.2 million deaths worldwide. Of these, 70% were caused by CVDs, with approximately 1.9 million deaths from ischemic heart disease and 900,000 deaths from stroke. Policy gaps remain a challenge, with many countries lacking adequate legally binding air quality standards. We recommend the adoption of WHO air quality guidelines, enhanced monitoring of air pollution levels, and increased investment in interdisciplinary research to understand the full scope of air pollution's effects on cardiovascular health. Addressing the global cardiovascular crisis linked to air pollution will require coordinated efforts from policymakers, healthcare systems, and global health organisations.

Keywords: Ambient air pollution; CVD global data; Cardiovascular health; World Heart Observatory.

Figure 1

Mean annual PM_2.5, 2019. Source: https://www.who.int/data/gho/data/indicators/indicator-details/GHO/concentrations-of-fineparticulate-matter-(pm2-5).

Figure 2

Trends in mean annual PM_2.5 concentrations by WHO regions, 2010–2019. Note: The shaded areas show uncertainty in estimates. Source: https://www.who.int/data/gho/data/indicators/indicator-details/GHO/concentrations-of-fine-particulate-matter-(pm2-5).

Figure 3

Number of all causes deaths attributable to ambient air pollution (left panel) and age-standardised mortality rates (per 100,000 people) attributable to ambient air pollution (right panel) for both sexes and by regions.

Figure 4

Number of IHD and stroke deaths attributable to ambient air pollution (left panels) and age-standardised mortality rates (per 100,000 people) attributable to ambient air pollution (right panels) for both sexes and WHO regions.

Figure 5

Age-standardised ischemic heart disease mortality rates (per 100,000 people) attributable to ambient air pollution for both sexes, 2019. Source: https://www.who.int/data/gho/data/indicators/indicator-details/GHO/ambient-air-pollution-attributable-death-rate-(per-100-000-population-age-standardized).

Figure 6

Age-standardised stroke mortality rates (per 100,000 people) attributable to ambient air pollution for both sexes, 2019. Source: https://www.who.int/data/gho/data/indicators/indicator-details/GHO/ambient-air-pollution-attributable-death-rate-(per-100-000-population-age-standardized); https://www.who.int/data/gho/data/indicators/indicator-details/GHO/household-air-pollution-attributable-death-rate-(per-100-000-population-age-standardized).

Figure 7

Short-term exposure: Percentage increase in the risk of cardiovascular diseases (selected outcomes) by type of air pollutant. Note: Each bar represents the percentage increase in the risk of developing the condition due to short-term exposure to specific pollutants (increase unit in pollutant provided in brackets in figure). CVD – Cardiovascular disease mortality; HF – Overall risk of heart failure incidence, mortality, and hospitalization; MI – Myocardial infarction incidence; Stroke – Stroke mortality; BC – Black carbon. Source: See Appendix Table 1 and Table 2 for the full set of data.

Figure 8

Long-term exposure: Percentage increase in the risk of cardiovascular diseases (selected outcomes) by type of air pollutant. Note: Each bar represents the percentage increase in the risk of developing the condition due to long-term exposure to specific pollutants (increase unit in pollutant provided in brackets in figure). CVD – Cardiovascular disease mortality; HF – Overall risk of heart failure incidence, mortality, and hospitalization; IHD – Ischaemic heart disease mortality; Str-inc – Stroke incidence; Str-mor – Stroke mortality; BC – Black carbon. Source: See Appendix for the full set of data.

Figure 9

Age-standardised ischaemic heart disease mortality rates (deaths per 100,000 people) attributable to household air pollution for both sexes, 2019.

Figure 10

Proportion of population with primary reliance on polluting fuels and technologies for cooking (%), 2021. Source: https://www.who.int/data/gho/data/indicators/indicator-details/GHO/gho-phe-population-with-primary-reliance-on-polluting-fuels-and-technologies-for-cooking-proportion.

Figure 11

Ischaemic heart disease and stroke age-standardised mortality rates (deaths per 100,000 people) attributable to household air pollution (a) and ambient air pollution (b), by income level for both sexes, 2019. Source: https://www.who.int/data/gho/data/indicators/indicator-details/GHO/household-air-pollution-attributable-death-rate-(per-100-000-population-age-standardized).

Figure 12

Countries with legal instruments containing Ambient Air Quality Standards. Source: https://www.unep.org/resources/report/regulating-air-quality-first-global-assessment-air- pollution-legislation.