Air Pollution Raises Heart, Cognitive Risks

International studies reveal that prolonged exposure to air pollutants negatively affects physical health, increasing the risk of heart attacks and accelerating cognitive decline in the elderly population.

Researchers from the Spanish Society of Cardiology (SEC) and the Spanish Heart Foundation (FEC) found that when PM₂.₅ particle concentrations exceed 10µg/m3, there are 22 additional heart attacks per 1,000 hospitalizations in the three days following exposure. Moreover, when concentrations reach 25µg/m3, the risk of dying during hospitalization due to a heart attack rises by 14%.

PM₂.₅ particles are extremely small airborne particles with a diameter of 2.5μm or less. They can be composed of a mixture of organic chemicals, dust, soot, and metals and originate from cars, trucks, factories, wood burning, and other activities. These particles are so small that they are invisible to the naked eye and can be inhaled, posing a significant health risk.

The Spanish study explains that when these particles enter the bloodstream, they trigger inflammation, oxidative stress, and endothelial dysfunction, a malfunction of the inner layer of blood vessels, which can lead to cardiovascular problems. “These mechanisms contribute to atherosclerosis and the rupture of arterial plaques, which can trigger a heart attack,” explained Jordi Bañeras, Researcher, SEC.

The work is pioneering because it is the first time this data has been analyzed across an entire country. To conduct the study, researchers collaborated with 122 hospitals in the National Health System (SNS), using environmental monitoring stations located within a 10km radius through geographic coordinates. The study included 115,071 patients over 18 years old diagnosed with acute myocardial infarction between 2016 and 2021.

Similarly, a study published in The Lancet Healthy Longevity evaluated the exposure of a group of middle-aged adults (45 to 64 years old) to pollutants such as nitrogen dioxide, nitrogen oxides, and suspended particles. Later, when participants were between 69 and 71 years old, their cognitive performance and brain structure were analyzed through memory tests, processing speed assessments, and MRI scans.

The results showed that higher exposure to nitrogen dioxide and suspended particles during middle age is associated with slower mental processing and cognitive decline in later life. Additionally, elevated levels of nitrogen oxides were linked to a reduction in hippocampal volume, while exposure to nitrogen dioxide and suspended particles was associated with enlarged brain ventricles, indicators commonly associated with cerebral atrophy.

This research provides new evidence that air pollution has lasting effects on the human brain, beyond its consequences for physical health. The authors highlighted that these findings reinforce the need to advance emission reduction policies as an essential public health strategy to protect long-term brain function.

In Mexico, large urban centers such as Mexico City, Guadalajara, and Monterrey frequently face pollution levels that exceed the limits recommended by the World Health Organization (WHO). According to data from the Mexico City Ministry of the Environment (SEDEMA), during the 2025 ozone season, concentrations reached up to 166ppb, while average PM₂.₅ levels in the metropolitan areas of Monterrey and Guadalajara often exceed 20µg/m3, doubling the recommended limits for protecting public health.