Urban communities, especially in large cities with densely populated areas, use cars and other vehicles for convenient transportation, and have a large number of industrial factories, resulting in both direct and indirect impacts on the environment. Yet, who would think about the consequences of air pollution that would come back to harm the human body itself in many systems? It’s not only the respiratory system that’s affected but also includes vital organs such as the “brain.”

Getting to Know PM 2.5

In the current era, there’s hardly anyone who doesn’t know about the tiny dust called PM 2.5 (particles smaller than 2.5 μM), which are about 20-30 times smaller than a strand of human hair. PM 2.5 isn’t the only type of air pollution that poses a health hazard, but there are also several toxic gases such as carbon monoxide (CO), sulfur dioxide (SO2), ozone (O3), and nitrogen dioxide (NO2), and it’s also found that heavy metals contaminate the air we breathe.

Over 90% of the world’s population is exposed to air pollution levels above the standard, and the problem of air pollution is not only found in Thailand but also in major cities around the world, leading to widespread health problems.

Data from the World Health Organization or WHO shows that every year, up to 7 million people die prematurely due to air pollution exposure, leading to diseases such as lung cancer, emphysema, heart disease, and brain diseases (World Health Organization).

The Dangers of PM 2.5

The pollution we breathe in doesn’t only cause issues at the lungs or the respiratory system, but PM 2.5 can also penetrate into the bloodstream, as well as through the olfactory nerves in the nasal cavity directly into the brain. Once these tiny particles enter the brain, it can trigger inflammatory processes in the brain, releasing various inflammatory substances causing brain cells to be damaged, leading to an earlier onset of cognitive decline. It’s also found to cause the formation of abnormal protein clusters in the brain (β-amyloid, α-synuclein, tau protein) that resemble those found in Alzheimer’s or Parkinson’s disease (Calderón-Garcidueñas, 2015) (Calderón-Garcidueñas L., 2016) and that the brain’s white matter (White Matter) seems to degenerate more than in healthy individuals (Chen J.-C., 2015).

A large study in 13 European countries involving over 300,000 people over an average of 14 years (ESCAPE Project) found that in groups exposed to more than 15 μg/m³ of PM 2.5, there was a significant increase in death rates by about 7% for every 5 μg/m³ increase in PM 2.5 (Beelen, 2013).

PM 2.5 and the Brain

In children, numerous studies have confirmed the relationship between PM 2.5 levels and abnormalities in intellectual development, such as reduced intelligence quotient (IQ), slower developmental progress (both Cognitive and Psychomotor Development), hearing and speech problems, and an increase in Attention Deficit and Autism rates by up to 68% (Suades-González, 2015) (Fu, 2019).

In adults, exposure to PM 2.5 has been found to triple the risk of Alzheimer’s disease and increase the risk of Parkinson’s disease by up to 34% (Fu, 2019), as well as significantly increase the risk of stroke. Every 10 μg/m3 increase in PM2.5 levels increases the risk of stroke by about 13%. Higher concentrations of these tiny dust particles increase the risk even more, even raising the death rate among those already suffering from stroke (Lin, 2017).

People exercising in locations with a high concentration of PM2.5 are at risk of brain health issues and an increased rate of strokes. Eating vegetables and fruits (more than 3.5 servings per day) can help reduce the impact of these tiny particles on the body due to the antioxidants found in vegetables and fruits (Lin, 2017) (Runhua, 2018).

In people suffering from migraine headaches, who are more sensitive to stimuli than the average person, PM2.5 dust and other types of air pollution can cause severe headache symptoms. It’s observed that during periods of high PM2.5 levels, such as in winter, there is a significant increase in migraine sufferers experiencing severe headaches requiring emergency room visits for injections, about 4 – 13% more than during normal periods (Chen C.-C., 2015).

From the medical information above, it’s found that PM 2.5 and other types of air pollution affect the body in several systems. Avoiding places with high levels of tiny dust, using appropriate protection, consuming enough vegetables and fruits with antioxidants, and being aware of helping to reduce air pollution are crucial for our own health and for those we love.

References

(2019, February 8). Retrieved from World Health Organization: https://www.who.int/airpollution/en/ 

Beelen, R. a.-N. (2013, 12). Effects of long-term exposure to air pollution on natural-cause mortality: An analysis of 22 European cohorts within the multicentre ESCAPE project. Lancet, 383. doi:10.1016/S0140-6736(13)62158-3

Calderón-Garcidueñas. (2015). Air pollution and your brain: What do you need to know right now. Primary Health Care Research & Development, 329-345. doi:10.1017/S146342361400036X

Calderón-Garcidueñas, L. (2016). Cerebrospinal Fluid Biomarkers in Highly Exposed PM2.5 Urbanites: The Risk of Alzheimer’s and Parkinson’s Diseases in Young Mexico City Residents. J Alzheimers Dis., 597-613. doi:10.3233/JAD-160472

Chen, C.-C. (2015). Association between Fine Particulate Air Pollution and Daily Clinic Visits for Migraine in a Subtropical City: Taipei, Taiwan. Int J Environ Res Public Health, 4697–4708. doi:10.3390/ijerph120504697

Chen, J.-C. (2015). Ambient Air Pollution and Neurotoxicity on Brain Structure: Evidence from Women’s Health Initiative Memory Study. Ann Neurol, 466–476. doi:10.1002/ana.24460

Fu, P. (2019). The association between PM2.5 exposure and neurological disorders: A systematic review and meta-analysis. Sci Total Environ, 1240-1248. doi:10.1016/j.scitotenv.2018.11.218

Lin, H. (2017). Ambient PM2.5 and Stroke: Effect Modifiers and Population Attributable Risk in Six Low- and Middle-Income Countries. Stroke, 1191-1197. doi:10.1161/STROKEAHA.116.015739.

Runhua, Z. (2018). Acute Effects of Particulate Air Pollution on Ischemic Stroke and Hemorrhagic Stroke Mortality. Front Neurol. doi:10.3389/fneur.2018.00827

Suades-González, E. (2015). Air Pollution and Neuropsychological Development: A Review of the Latest Evidence. Endocrinology, 3473-3482. doi:10.1210/en.2015-1403