Most of us have heard arguments about climate change and how increasing levels of pollution are destroying the Earth and its natural resources. Air pollution, however, has a much more direct impact on us. In particular, tiny particles in the air invisible to the naked eye are causing big problems for our hearts.

Air pollution is the combination of gases and particles found in the air we breathe. They are mainly released by motor vehicle exhaust fumes and industrial factories. When you think about pollution, you may picture a dark grey hue covering entire cities, with black smoke rising from old factories and old cars. You may think of cities far away, somewhere densely populated such as Beijing, China, or Delhi, India—or maybe the thick smog covering Los Angeles—because it is only what we see that can cause us harm, right?

Wrong. The air we breathe is full of tiny toxic particles that we can’t see, which cause direct harm to our cardiovascular system.

Air pollution and the cardiovascular system

An estimated 4.2 million premature deaths occur every year worldwide as a result of exposure to air pollution. Almost half of these are from cardiovascular diseases alone. Scientists have found that when we breathe in polluted air, tiny particles enter the blood and are carried to the heart, where they can change how the heart works. Rising levels of these particles, known as particulate matter, have been linked to higher rates of heart failure, heart attack and abnormal heart rhythms called arrhythmia.

Research in laboratories around the world has found particulate matter can damage the inside of blood vessels, alter the electrical activity of the heart to cause abnormal beat rhythms and even change the structure of the heart itself. In people who already have heart disease, these changes can increase their risk of heart attacks or stroke. Over time, both the particles and their negative effects can build up in the body, which could lead to new heart problems in healthy people.

But it’s not all doom and gloom! Pollution levels have decreased in recent years, although many countries have not yet hit the air quality standards set by the World Health Organization. Drastic change in air quality policies is needed but, in the meantime, we can all play our part to reduce pollution. During the initial lockdown due to the coronavirus pandemic in March 2020, the levels of air pollution around the world significantly decreased due to reduced vehicle use and industrial activity. One study found this resulted in 11,000 fewer air pollution-related deaths across Europe.

Our best fight against toxic particles is to reduce overall pollution. Making small changes such as walking, biking and using public transportation when possible could go a long way and save lives.