2020-03-11 08:17

Microparticles affect our health and environment. They can make us ill and shorten our life expectancy. Today, 80% of the world’s population are exposed to particle levels that are higher than the limit values recommended by WHO.

Particles are one of the most common air pollutants besides gases that we are exposed to. They come from natural sources and from anthropogenic sources that we humans have created. Organic particles come from e.g. erosion, volcanoes and pollen. The most common particles created by man come from road wear, combustion engines and industrial processes.

The smallest particulates are the most harmful

Particulate matter is usually categorized by size PM 10, PM 2.5 and PM1. PM 10 refers to particles whose diameter is less than 10 micrometer (µm), in comparison a hair has a diameter of 70 µm. These particles are primarily created from road wear and have a negative impact on our breathing capacity.  Humans cannot see particles that are smaller than PM 10. 

Particulates that are smaller than 2.5 µm are known as PM 2.5 and are created by combustion engines and industrial processes. They can penetrate down into our lungs and our eyes. The smallest particles PM 1, whose diameter is less than 1 µm, are the most dangerous as they can pass through our bodily filters, such as the nose’s mucous membranes and cilia and into our bloodstream.

The supply air needs be filtered carefully

In buildings with inferior ventilation, the particles remain indoors and the humidity can be too high. A good ventilation system that is adapted to the activities in the building is important in order for the air quality to be good. The ventilation must be able to remove air pollutants continuously from the building, interior and residence.

For premises where people reside, the supply air should meet the criteria of PM2.5 ≤ 5 µg/m3, i.e. no more than 5 micrograms of PM2.5 particles per cubic meter.  A filter that has the filter class ePM1 50% is a good level for premises that are located in less polluted places. This means that 50% of particles that are less than 1 µm are filtered out. In areas with high levels of air pollution, filters of at least ePM 1 80% should be used.

The majority of the world’s population live in cities that have higher particle levels than the threshold values recommended by WHO. More stringent legislation, increased awareness and expertise about particles have meant that the quantity of dangerous particles has dropped, but it is a process that takes time. This makes it more important that we ventilate and use filters that guarantee good quality of supply air.

air quality