Clearing the Air—Pollution and the Risks for Dementia

Author: Evelyn Fistler

Editor: Anita Enoma

Introduction

Air pollution has increased drastically over time, with annual fine particulate matter (PM2.5) concentrations in urban areas showing an increase from the years 2000-2019, specifically in regions like Southeast Asia, the Middle East, parts of South America, East Africa, and Eastern China. Regions such as North America and Europe have fortunately shown a reduction in air pollution (Pierre et al., 2023), however, this does not mean that all areas are guaranteed safe. Contributing factors like burning fossil fuels, deforestation, and waste disposal greatly contribute to air pollution (Air Pollution and Your Health, n.d.).

How Air Pollution Affects the Brain

PM2.5 is known to enter the lungs and circulate through the bloodstream, eventually ending up in the brain. Since these particles are so small and are emitted through power plants, vehicles, industrial facilities, and smoke from fires, research for this issue and its correlation to dementia is ongoing (Grande et al., 2021). Induced by PM2.5 exposure, oxidative stress is a factor that contributes to inflammation within the brain (Li et al., 2022), though research has shown that carriers of the APOE e4 allele tend to have a much higher risk for dementia incidents, even within a lower exposure setting to PM2.5 than those without the gene. Furthermore, declining olfactory functions are early markers for dementia, and air pollution is associated with  Alzheimer’s disease-related pathology in the olfactory bulb long before dementia onset.

The allele APOE e4 had been previously shown to be associated with poor odor identification (Andersson et al., 2023). Given this information, the association of air pollution and its impact on the olfactory system is important to research. Currently, this topic is an ongoing investigation, where vulnerability to poor odor identification due to air pollution in females and physically active individuals was studied. Biological aspects such as blood-brain barrier permeability, females being more vulnerable to olfactory damage due to their number of neurons and glial cells compared to males, and increased respiratory rates in active individuals could have an impact on the olfactory system as well (Nikolaou et al., 2025).

What Next?

Globally, this issue will require adaptation and preventive measures to ensure the health of civilians within busy areas. The use of clean energy is highly recommended to be strengthened in China by reducing fossil fuel consumption and instead utilizing advanced technologies that rely on solar, nuclear, and hydropower, while also limiting high energy consumption and emission enterprises through industrial upgrading. Air pollution control and revision of quality air standards are of high importance, as recognition of air pollution-causing health risks can help citizens. This will also help educate the public on the risks from unhealthy air quality and what steps need to be taken for health protection (Shi & Duan, 2022).

Within the United States, measures are being taken to ensure the public is informed while state-specific strategies occur in order to prevent health risks. Limiting the co-benefits of CO₂ emission is shown to be effective, and while cost is a concern, fuel switching and efficiency improvements are beneficial (Ou et al., 2020).

Conclusion

Further epidemiological investigations on PM2.5 throughout different regions of the world may help narrow down specific areas of higher risk for neurological disease development, however, change is required in order to help citizens globally. Promotion of fossil fuel reduction, implementation of stricter emissions standards, and energy conservation are some of the factors that may reduce health risks due to air pollution, but adopting cleaner technology and enforcing standards are crucial steps to help citizens also invest in cleaner energy use. Scenarios such as the Clean Air scenario help to promote strategies targeting advocacy for global emission reduction through lifestyle choices and industrial factories, while still including climate changes such as emissions through vegetation that are prevalent today (Amann et al., 2020).

Since the exact cause of neurological conditions such as dementia and Alzheimer's is unknown, researchers can instead study how society and environments affect the brain, providing information that shows the highest risks for disease development. While pollution is a difficult issue to tackle, spreading awareness of the dangers of pollution and how it affects societies globally will help researchers understand and implement ideas that can reduce health risks and instead create a better world for everyone.

References

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