According to the World Health Organization (WHO)[1], air pollution is one of the greatest global health risks.
This article uses the definition of "Particulate Matter" to describe how great the risk is and how airwalls can prevent it.
"Particulate Matter" from the U.S. EPA
The U.S. Environmental Protection Agency EPA[3] was a pioneer in the consideration of air pollution. As early as 1987, it introduced the "National Air Quality Standard for Particulate Matter", which set global standards.
It attempted to reproduce the separation behavior of the upper respiratory tract and defined the aerodynamic diameter[4]. Initially, it concentrated on particles of the size PM 10 µm. Within a few years it became clear that the definition of PM 10 was not sufficient because the health risk appeared to be even greater for smaller particles.
In 1997, PM 2.5 was added to the American directive - particles with an aerodynamic diameter which is a quarter of PM 10.
Finally, Ultra Fine Particles (UFP), particles with an aerodynamic diameter of less than 0.1 µm[5], followed. This puts UFP in the size range of viruses, bacteria and large molecules.
At the time of the introduction of UFP, the World Health Organization (WHO) was probably already involved, adopting the EPA's definitions.
Sources of Particles
Particles occur in nature, but are also man-made.
Natural causes include forest fires, volcanic lava, sea spray and smoke. Pollen, bacteria and viruses can also be of that size.
Many particles are by-products of the combustion of gas, coal or hydrocarbons (such as petrol or diesel) or biomass. Certain processes generate solid particles, such as the loading of bulk goods, waste disposal, working with concrete or demolition work. Wear plays an important role. This is easy to see from the abrasion of tires or (gym) shoes.
There are a variety of sources indoors, including cooking, printer toner or vacuuming dust! The biggest cause is humans, because skin flakes or fiber particles are also particles.
UFPs can be specifically produced as fine particles to enable a wide range of applications in medicine and technology.
Health risk due to air pollution
The WHO has declared air pollution to be one of the greatest environmental risks to health worldwide.
The burden of disease attributable to air pollution is now considered to be on a par with other major global health risks such as unhealthy diets and tobacco consumption. Since 2015[6], air pollution has been recognized as a risk factor for non-communicable diseases such as heart disease, stroke, chronic lung disease, asthma and cancer.
And it is not a "third world" problem: In 2019, 99% of the world's population lived in places where WHO air quality guidelines were not met. Air pollution is linked to 6.7 million premature deaths every year.
In Germany and many countries in the EU and around the world[7], the WHO limits are only met on mountain tops.
While it was originally assumed that ultrafine particles UFP posed the greatest danger, PM 2.5 now appears to be the main culprit. These particles can even cause lung cancer.
Indoor air pollution
For many years, the bureaucrats only looked at car exhaust fumes. The realization that we are dealing with a comprehensive problem is slowly gaining ground.
When we hear the word air pollution, we think of outdoor air. But we spend about 90% of our lives indoors and the air inside buildings is between two times worse[8] and five times worse[9] than the air outside[10].
The European Commission writes that particles released in buildings are considered to be the main cause of the increase in cancer in the European population."
Limit values: AQG
The WHO publishes the AQG "Air Quality Guidelines", a huge, professional document to which many doctors around the world have contributed.
They were published in 2005. In 2021, they were significantly tightened because the health risk is even higher than assumed almost 20 years ago.
The "Ambient Air Quality Directives" of the European Community have been trying to enforce looser limit values than the AQG since 2005. The argument was that these were not economically feasible and not binding. Since 2021, the European limit values have been obsolete and will probably come closer to the AQG.
That is why we are already aligning ourselves with them today.
Improving air quality
Here, too, we are confronted with a jungle of regulations and laws.
We therefore present the most important norms and standards that (can) be used in LWT airwalls to improve air quality.
Indoor air according to VDI 6022
This standard regulates the hygienic requirements for room air technology. It must be in perfect hygienic condition, create a safe indoor air quality and correspond to the current state of the art.
The Federal Office for Radiation Protection (BfS) states that air hygiene has a proven positive effect on the health of employees.
Filters in accordance with with DIN ISO 16890-1
LWT can use all commercially available filters.
Based on WHO guidelines, we recommend PM 2.5 filters with a high degree of separation.
These are very rare, so PM1.0 60% filters can also be used. We do not need larger fans for this, but specially adapted fans. These should always be ordered, even if no filters are used on the air walls, as filters can then be retrofitted.
HEPA filters according to EN 1822 and ISO 29463[11]
HEPA filters separate particles with an aerodynamic diameter of 1 µm.
ISO 29463 from 2011 is intended to provide clarity in the jungle of standards and is based on the EN 1822 filter standard from 1998, which includes the familiar EPA, HEPA and ULPA filter classes.
Recent studies in hospitals and schools have shown that HEPA filters in combination with UV light can effectively trap viruses and bacteria, including the coronavirus COVID-19.
Disinfection with UV-C radiation
UV-C radiation is generally able to kill bacteria and viruses.
However, viruses and bacteria must be irradiated long enough, the radiation must be encapsulated to protect people and the correct wavelength must be used. Wavelengths around 254 nm are usually used. Far-UV-C with a wavelength of 222 nm does not always work.
Ionization of the air
Natural air contains ions that can purify the air. The proportion of ions is highest near waterfalls, the sea or rivers.
In ventilated or air-conditioned rooms, the number of ions (10-100 ions/cm³") is significantly lower. This increases indoor air pollution.
LWT works with companies that can ionize and purify air in a natural way[12].
Airwall maintenance is important
Every air handling unit (AHU) must be regularly maintained and cleaned to improve air quality. Filters must be replaced and UVV and hygiene inspections must be carried out.
Only systems that are regularly maintained and adjusted will work correctly. We recommend doing this at least once a year and whenever necessary.
Sources:
[1] WHO: World Health Organization ist Teil der Vereinten Nationen (UN) mit Sitz in Genf
[2] Die Definition des Feinstaubs basierte auf der Johannesburger Konvention von 1959 und nutzte 5 Mikrometer (µm)
[3] U.S. Environmental Protection Agency
[4] Partikel von weniger als der unteren Grenze werden vollständig einbezogen, bei größeren wird ein gewisser Prozentsatz gewertet
[5] Diese Grenze ist nicht zufällig gewählt. 0,1 µm sind 100 Nanometer, dem Beginn der Nanowissenschaft
[6] Im Jahr 2015 verabschiedete die Weltgesundheitsversammlung eine bahnbrechende Resolution zu Luftverschmutzung
[7] Österreich folgt in vielen Fragen Deutschland. Die Schweiz orientiert sich an der UN, also der WHO
