The global study shows air pollution could triple cases of heart disease by 2045

The global study shows air pollution could triple cases of heart disease by 2045

Despite advances in air quality, global heart disease deaths linked to particulate pollution have increased, particularly for seniors and developing countries, with women facing the steepest future increases.

Study:Global burden of cardiovascular disease attributable to particulate matter pollution, 1990-2021– Photo credit: Nadyginzburg/Shutterstock.com

A new study analyzing data from the Global Burden of Disease (GBD) 2021 study and published in the publication inBMC cardiovascular disordersMay 2025 showed a significant increase in cardiovascular disease from particle pollution from 1990 to 2021.

background

The 2021 Global Burden of Disease (GBD) Study identifies cardiovascular disease as the leading cause of death and disability, with ischemic heart disease and ischemic stroke contributing the most in years of life (DALYS) worldwide. Daly is a measure of disease burden and combines the impact of premature death and years of disability.

The burden of cardiovascular disease is significantly higher in countries with lower social, educational and medical development (sociodemographic status) compared to countries with higher sociodemographic development.

Specific risk factors, including air pollution, lack of physical activity, smoking, high blood pressure and high cholesterol, can accelerate the progression of cardiovascular disease. Exposure to ambient particulate matter (PM) is a potent risk factor for cardiovascular disease.

Among the three main PM categories, fine PM 2.5 (diameter less than 2.5 μm) is of particular concern because it can enter the bloodstream through the respiratory system and trigger systemic inflammation, oxidative stress, and endothelial dysfunction. All of these processes can contribute significantly to the development and progression of cardiovascular disease.

This study used the GBD 2021 data to analyze cardiovascular disease attributed to PM2.5 exposure across global regions over the past three decades.

Study design

The study analyzed data from the GBD 2021 study, a collaborative project involving more than 11,000 contributors from more than 160 countries and regions. All available data were reviewed and modeling techniques were applied to generate estimates. The project estimates 371 diseases and injuries in 204 countries and regions worldwide from 1990 to 2021.

In the current study, researchers used the GBD 2021 data to assess age-standardized cardiovascular disease mortality rates and DALYs from PM 2.5 from 1990 to 2021. Predicting the future burden of cardiovascular disease by 2045.

Study results

The study reported that the global number of deaths and DALys associated with PM 2.5-induced cardiovascular disease increased by 91.68% and 78.89%, respectively, between 1990 and 2021. Despite these increases, age-standardized mortality rates (adjusting for the effect of age on mortality) and Dalys decreased with age of mortality. The reduction was more pronounced in women.

These changes in the age group distribution of the global burden of cardiovascular disease may be attributed to rapid population aging and global population growth.

A disproportionate distribution of global PM-attributable cardiovascular disease was observed across age groups. Significantly greater burden was observed in older populations.

From 1990 to 2021, age-standardized mortality rates and DALYs increased while the absolute burden increased in older populations due to population aging. This trend is particularly important among older adults (80 years of age).

The proportion of deaths and Dalys due to ischemic stroke was significantly higher than that of ischemic heart disease in the elderly. This may be due to the brain's greater sensitivity to ischemia compared to the heart. In the brain, ischemia can cause irreversible damage in minutes, while ischemic heart disease can be improved with medications, stents or surgery.

Furthermore, ischemic stroke often results in severe long-term disability, increasing DALYs more in seniors.

The study observed national-level differences in the burden of cardiovascular disease. Countries with high and low sociodemographic status showed lower age-standardized mortality rates and DALYs. In contrast, countries with moderate sociodemographic status showed higher age-standardized mortality rates and DALys.

The researchers provided several explanations for careful interpretation of these observations. In countries with high sociodemographic status, a lower burden of PM-driven cardiovascular disease may be associated with better medical resources and stricter environmental management policies, such as:

In countries with moderate sociodemographic status, rapid industrialization and urbanization can lead to a significant increase in pollutant emissions without improved health systems, leading to a higher burden of disease.

The study found differences in mortality and Daly rates between the sexes over the period 1990-2021, with women experiencing a lower age-standardized burden of disease and a significant decline in these rates than men. This may be due to the protective effects of estrogen, a female reproductive hormone, on the cardiovascular system, which may have lasting benefits even after menopause due to protective effects and metabolic memory. Additionally, women have historically been less likely to be employed in construction, agriculture, or other outdoor jobs, resulting in lower exposure to ambient PM 2.5. Behavioral factors such as those in some female populations could also contribute to observed differences.

The study predicted a three-fold increase in deaths and a nearly 2.5-fold increase in DALYs from cardiovascular disease attributable to PM 2.5 exposure by 2045, with women seeing larger increases in these absolute numbers. This projected increase refers to absolute numbers, not age-standardized rates.

This increase may be associated with several factors, including a global increase in the elderly population and higher exposure to PM pollution due to industrialization and urbanization.

Investigate significance

The study reports a global increase in the absolute cardiovascular disease burden attributable to PM 2.5 exposure despite improvements in age-standardized rates.

The study observed age, gender and sociodemographic status differences in disease burden, highlighting the need to prioritize strict air pollution controls, early screening and allocation of health resources to high-risk regions and among vulnerable populations. It is also important to recognize that, as with any modeling study, these projections have uncertainties.

The original paper notes limitations such as the primary data quality in some regions, the focus on PM2.5 excluding other pollutants, and the specific CVD results examined, which could influence estimates and future projections.

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