Particulates is a mixture of solid and liquid suspended particles with a very small diameter.Depending on the particle size and composition, particulates can have a lasting effect on the respiratory tract and the cardiovascular system. The air-Q air analyser can measure particulates of different particle sizes (PM₁₀, PM₂,₅, PM₁).
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The term "dust" describes a complex physical-chemical mixture of airborne, liquid or solid particles. These are also referred to as PM (English: particulate matter) and generally as particles in German.
Particles with a very small diameter that can reach the bronchial tubes are called "particulates" or even ultra-particulates. There are very large differences in the composition of different particulatess. particulates can contain both organic and inorganic material.
Different particle sizes that can be measured by the air-Q air analyser, for example, are referred to as PM₁₀, PM₂,₅ or PM₁.
particulates has a high absorption potential for gaseous trace substances. As a result, particularly pollutants with comparatively high boiling points (e.g. pesticides and plasticisers) accumulate very easily on particulates and increase the health risk by breathing air contaminated with particulates.
Since the harmfulness of particulates depends on the size of the particles, different limit values have also been determined. In general, the smaller the particulates particles are, the deeper they can penetrate into the lungs and bloodstream. This increases their danger to humans.
For particulates PM₁₀ (whose particles are smaller than 10 µm), the Federal Environment Agency sets a daily limit of 50 μg/m³ and an annual mean of 40 μg/m³ for outdoor air. The daily limit value may only be exceeded on 35 days a year.
particulates with smaller particles can penetrate even deeper into the respiratory tract. Therefore, since 2015, the annual limit value of 25 μg/m³ in outdoor air set by the World Health Organisation (WHO) has also applied to particulates PM₂,₅ (particles with a diameter of less than 2.5 μm) in living spaces as an assessment value.
So far, there are no standardised measurement methods for even smaller particulates particles of the PM₁ category, which is why there is still no legal limit value for these particularly dangerous particles - because 100 % of them reach the alveoli. Particles this small are also referred to as ultra-particulates .
The exact assessment of the health effects of particulate matter is difficult due to its inconsistent composition. However, it is generally assumed that particulates is harmful to health. In contrast to other pollutants, there are no real threshold values for the concentration of particulates below which no health effects would be expected - any amount, no matter how small, is considered harmful.
Regardless of the type of particulates, the particles irritate the respiratory tract and can lead to inflammatory changes there. Depending on their composition, pollutants bound in particulates can cause allergic reactions or, as in the case of coal dust, destroy the alveoli in the lungs.
The smaller particles in particular can also enter the bloodstream via the pulmonary alveoli and thus have a lasting effect on the cardiovascular system. Certain substances can also increase the risk of heart attack (e.g. sulphurous particulates) or have a carcinogenic effect (e.g. asbestos).
In addition, irritation of the mucous membranes of the eyes, nose and throat may occur. Damage to the central nervous system cannot be ruled out either.
Natural emissions (e.g. from soil erosion, oceans, volcanoes, forest and bush fires) and biogenic particles (e.g. viruses, spores of fungi and bacteria, pollen drift, excretions of house dust mites) are considered to be particularly frequent particulates sources. However, man-made air pollution is without doubt the main cause of particulates.
In the outdoor air, particulate matter originates mainly from emissions from industrial plants, power stations and road traffic. Likewise, agricultural animal husbandry produces a considerable amount of ammonia, which forms particulates in the atmosphere after chemical reactions. Wood fires in residential areas contribute to air pollution by particulate matter on cold days.
Through open windows and via shoes and clothing, these pollutants can also get into indoor spaces and thus into the indoor air and impair the air quality. Furthermore, candles, tobacco smoke, open fireplaces and cooking and frying also contribute to particulates pollution.
In addition, allergens from pets and chemicals from carpets and furniture can cling to the particulates particles. particulates particles can also enter the indoor air when vacuuming and through office equipment such as printers, copiers and computers.
particulates is measured by means of optical scattering. An infrared LED and a detector are separated by a wall and never "see" each other directly. Only when a particulates particle appears in the light of the LED does the detector see a flash. The sensor counts these flashes and depending on how bright they are, it detects whether it is a large particle (bright, PM₁₀) or a very small particle (dark, PM₁).
The advantage of the sensor used is the particularly good measuring accuracy compared to very expensive particle counters. The disadvantage of the measuring principle is a cross-sensitivity to water vapour or mist. These fine water droplets also flash at very high relative humidity (> 90 %) and are counted as particulates.
To get to the bottom of the causes of dangerously high concentrations of particulates in indoor air, it helps to use an indoor air measuring device such as the air-Q, which can measure all three different sizes PM₁, PM₂,₅ and PM₁₀ via sensors. You can order the air analyser in the online shop.