Did you know? Tiny particles of air pollution spread throughout the human body from head to toe and affect all our organ systems, leading to things like dementia, lung and heart diseases, infertility, and mental deterioration.

Globally, air pollution kills more people than cigarette smoke, hence why the World Health Organization refers to air pollution as the “silent killer.” The human body is affected by various pollutants in the atmosphere. However, the pollutants particulate matter (PM2.5), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO) are particularly dangerous because they reach every nook and cranny of our body. Once these particles enter the body, they travel through the bloodstream and begin to affect all organ systems regardless of their concentration.

But how exactly do air pollutants reach all the human organ systems?

The Respiratory System

A person breathes in 11,000 liters of air daily through the nostrils, which pass through the trachea, bronchi, and alveoli, and then enter the blood circulation system. This means that small toxic substances in the air impair all these organs one after the other.

Our body does not have a combat mechanism against air pollution, so it responds to air pollution in the same way it responds to an infection. Thus, upon entering the body, our immune cells mistakenly identify toxic substances as bacteria and try to destroy them by releasing inflammatory substances. 

This inflammatory response can lead to complications including breathing problems, asthma, pulmonary edema, and even lung cancer. However, the minor issues that occur every day, including inflammation of the nasal cavity, facial pain, stuffy nose, runny nose, swallowing of discharge into the nose, partial loss of smell, headache, fatigue, toothache, and cough, all decrease the quality of daily life little by little. As soon as the winter season comes, the number of patients visiting respiratory specialists in public hospitals doubles due to these symptoms.

The Cardiovascular System

Did you know that air pollution also affects the heart? Oxygen-rich coronary arteries around the heart work nonstop to keep our blood pumping. However, when these blood vessels are exposed to tiny amounts of toxic substances from the air, inflammatory responses take place. Abnormal changes due to this inflammation, such as hardening and narrowing of blood vessels (atherosclerosis) and weakening of the vessel wall, result in reduced blood supply to the heart, which can subsequently cause sudden cardiac arrest. 

85% of all strokes happen to people in low and middle-income countries like Mongolia. Perhaps this is one of the prominent examples of the consequences of a failure to address air pollution in these countries. In Mongolia, it is reported that hospitalization for ischemic heart disease is strongly associated with air pollution. In the last ten years, 35 thousand years of human life have been lost due to this condition in the country (Clean air city conference report 2020, p 30). 

Not only the heart, but all the blood vessels that carry toxic substances are damaged, resulting in the hardening of arteries, stagnation of blood flow, and eventually, the shortening of life. But remember, sudden cardiac arrest is preceded by symptoms of chest pain, pressure on the chest, shallow breathing, and cold hands and feet. So pay attention to these signs!

The Nervous System

In recent years, it has been found that air pollution not only damages the respiratory and cardiovascular systems but also affects the central nervous system and is associated with stroke, Alzheimer’s disease, Parkinson’s disease, and neurodevelopmental disorders. The tiny particles of air pollutants, carried by the bloodstream, crosses the blood-brain barrier and reaches the central nervous system, leading to inflammatory responses in the brain. There is also a reported mechanism of air pollutants bypassing the blood-brain barrier to directly enter the brain from the naval cavity through the olfactory bulb. 

Children’s brain and mental development are also affected by air pollutants, causing long-term and short-term consequences. For example, in a study of 15,000 English children, PM2.5, PM10, NO2, and SO2 in the air were associated with lower language and cognitive development scores at the ages of five and seven. A study conducted in Mongolia found that PM2.5 exposure during pregnancy was associated with behavioral problems in children at four years old.In Mongolia, as of 2018, nervous system diseases are among the top 5 causes of illness among hospitalized patients (215.5 per 10,000). Also, study results are coming out one after another about air pollutants affecting mental health with links to depression, anxiety, dementia, and suicide.

The Gastrointestinal System

The digestive system is home to 100 trillion microorganisms, and the environment they create (microbiota) determines whether we stay healthy. The microorganisms form a layer on the walls of the digestive system, absorb nutrients, and play a vital role in the immune system. 

Air pollutants affect the structure and function of this microbiota: the normal functions of the microorganisms are lost, the permeability of the intestinal wall increases, and the inflammatory response is activated. This increases susceptibility to inflammatory bowel disease, appendicitis, irritable bowel syndrome, and enteric infections. Also, since the liver is responsible for detoxifying the digestive system, an increase in toxins in the air can induce liver disorders.

The Reproductive System

One of the most disturbing effects of air pollution is its effect on the reproductive system. A study involving over a thousand women living in Ulaanbaatar city showed that higher concentrations of sulfur dioxide in the air were associated with a higher chance of miscarriage. Other toxic substances such as nitrogen dioxide, carbon monoxide, PM10, and PM2.5 also reduce fetal viability.

Toxic substances such as PM2.5 in the air penetrate the barriers of reproductive organs, such as the blood-testis barrier in men, the placental barrier in women, and the epithelial barrier, causing damage at the molecular level. There are also associated incidences of hormonal imbalances and infertility.

What Can We Do?

Air pollution affects us constantly, whether asleep or awake, as long as we are breathing. According to the 2021 updated recommendations issued by the World Health Organization, there is no such thing as a healthy level of air pollution, so we should always aim to reduce our exposure from the recommended level to zero. Polluted air continually reminds us to protect ourselves by wearing a mask, running an air purifier at home, and avoiding using fossil fuels as much as possible. Most importantly, as citizens, we must continue to hold our government accountable all-year round for this public health crisis. 

To encourage you to take action in this regard, we present simple and practical ways to protect ourselves from air pollution on our website, including information such as wearing a mask regularly and using an indoor air purifier. Also, upon visiting the “Take action” section, you can pledge on your social media account and share it with others. Most importantly, applying it in your life every day is vital.

Edited by: Enkhuun Byambadorj, Azjargal Tsogtsaikhan