How air pollution increases the risk of cardiovascular diseases

The Bundes-Immissionsschutzgesetz (Federal Immission Control Act) regulates air pollution in Germany, specifically “changes to the natural composition of the air, especially as a result of smoke, soot, dust, gases, aerosols, vapors or odors”.

Numerous air pollutants can become harmful to human and animal health if their concentrations in the air exceed certain levels. The main air pollutants that have been proven to pose health risks include particulate matter, ozone, nitrogen dioxide and sulfur dioxide.

These air pollutants are primarily caused by humans through energy production, energy consumption, road traffic, agriculture and the production of goods, especially in the area of industrial production. There are also natural causes such as forest fires.

Of the air pollutants mentioned, particulate matter is the main one that causes changes to the arterial vessel walls (arteriosclerosis) and thus also leads to cardiovascular diseases.

Particulate matter is created by a wide range of both natural and man-made sources, especially:

• exhaust gases produced by internal-combustion engines
• abrasion from car tires, brakes and road surfaces
• emissions from heating systems and power plants
• gases from agriculture that contribute to the formation of particulate matter

Particulate matter falls within the air components described as “airborne particles”. Specifically, the term refers to all airborne particles with a diameter of less than 10 micrometers. Finer particles with a diameter of less than 2.5 micrometers are known as the “fine fraction” of the particulate matter. These particles are about the size of a red blood cell in the human blood and are invisible to the naked eye. There are also ultrafine particles, which have a diameter of less than 0.1 micrometers (one hundred billionths of a meter).

Particulate matter, especially ultrafine particles are considered to be particularly harmful to health compared to other air pollutants. This is because they can penetrate very deeply into the airways with the result that they remain in the body rather than being exhaled with the airflow like other air pollutants.

Air flows between the lungs and the cardiovascular system via the pulmonary alveoli (air sacs). Inhaled particulate matter can penetrate to this point and enter the bloodstream via the alveoli.

The processes that then follow have not yet been fully researched but experts believe that the particulate matter can trigger inflammation in the vessel walls. This increases the risk of arteriosclerosis – a vascular disease also known as “atherosclerosis” or “vascular calcification”.

Arteriosclerosis is associated with progressive damage to the arterial blood vessels: the vessel walls harden and deposits form in them that constrict the blood vessels.

Due to these vascular changes, arteriosclerosis can cause a number of cardiovascular diseases.

These include:

• coronary heart disease (ischemic heart disease)
• stroke
• heart attack
• high blood pressure

To reduce the health effects of particulate matter, the following limit values for particulate matter apply in Germany and Europe as a whole:

• The annual mean value must not exceed 40 micrograms per cubic meter of air.
• The daily mean value must not exceed 50 micrograms per cubic meter of air on more than 35 days per calendar year.

Although the level of particulate matter in Germany has been significantly reduced since the 1990s, in many places the levels are often still high enough to be damaging to health, especially in urban areas.

The National Air Pollution Control Programme established in 2019 aims to further improve air quality in Germany by 2030. For example, it establishes emission limits for various industrial sectors. The main objective of the program is to significantly reduce the levels of particulate matter as well as substances such as ammonia that promote its formation.

The latest information about the air quality in your region and Germany as a whole can be found on the Federal Environmental Agency (Umweltbundesamt) website.