What is house dust?
The dust in our indoor spaces is a mixture of various organic and inorganic particles. These particles can be suspended in gases, including the air, for long periods of time. On the one hand, house dust enters the room from outside - such as soot, pollen, fungal spores, rock dust, metal particles or smoke particles, bacteria and fibres. On the other hand, dust can also be produced inside a room, for example by skin flakes, burning candles or incense sticks, petting pets, or by outgassing volatile organic compounds(VOCs) from wall paints, wood preservatives or cleaning agents.
House dust can be produced by natural processes or by humans (i.e. anthropogenic) in chemical, mechanical and thermal processes or incomplete combustion. The most important anthropogenic emission sources include industry, agriculture and road traffic.
Dust is differentiated either by its size or by its type. In terms of particle size, a distinction is made between coarse dust, particulates, respirable dust and finally ultra-particulates. Ultra-fine particles include fibre dust, rock dust, pollen and, of course, house dust.
House dust also contains skin flakes, food residues, mite faeces and even microorganisms. The particles float through the air, partly combine with each other and with other pollutants, and after a while sink to the ground due to gravity. There they are visible to all inhabitants as fluff or woolly mice.
House dust: What effects do voles have on our health?
The health hazards of house dust vary according to the size and composition of the particles and the form in which they enter the body. A distinction is made between three types of ingestion:
- through breathing (inhalative)
- by swallowing, e.g. in infants (oral)
- through contact with skin and mucous membranes (dermal)
Larger particles are often stopped by the nose, mouth and upper respiratory tract, so they usually do not reach the lungs. These house dust particles mainly damage the external organs. They thus attack the skin and mucous membranes and can cause irritation or even inflammation of the eyes.
Smaller dust particles often reach the lungs. The pollutants can enter the bloodstream and eventually all organs. This leads not only to damage to the cardiovascular system, but also to effects on the internal organs that have been little researched so far. In particularly serious cases, various types of cancer can be the result. Pathogens of infectious diseases can also dock on to house dust. A possible consequence is inflammation in the body. It has been proven that even meningitis bacteria can enter the body via dust particles and thus cause the life-threatening meningitis.
Diabetes, obesity as well as thyroid diseases and even infertility are now also associated with polluted air.
However, most of the damage caused by house dust affects the respiratory tract. Particularly patients with a history of COPD (chronic obstructive pulmonary disease), for example, experience an aggravation of their symptoms due to polluted house dust. Dust can also be a trigger for tracheitis or even pneumonia.
Polluted air particularly often leads to atopic diseases. These are triggered by allergens - i.e. actually harmless substances that the body classifies as harmful and fights against accordingly. Flower pollen as well as the excrement of house dust mites or even animal hair and mould spores cause allergic reactions already within the first year of life. Over time, these reactions develop into allergic rhinitis (hay fever), allergic asthma or atopic eczema (neurodermatitis).
How do we protect our health?
The dangers of house dust and protection against it should not be taken lightly. Even in the womb, exposure to pollutants can affect the child's development. Therefore, it is important to know exactly which pollutants are in the air in order to be able to remove them effectively.
If symptoms appear or even intensify, it is essential to consult a doctor in order to recognise and treat chronic or even life-threatening diseases at an early stage.
In addition, it should be ensured that the window remains closed when the pollutant load of the outside air is high - in this case, wide-open doors or windows facing the courtyard should be used to ensure an exchange of air. Especially during the pollen season, allergy sufferers should only ventilate their rooms at certain times - in the city in the morning and in the countryside in the evening.
If the particulates pollution is high, sports and heavy physical work should be avoided. This is because faster breathing during physical exertion leads to increased absorption of pollutants.
To make indoor air healthier, you should always trust your own nose when buying furniture and home accessories. Everything that emits perceptible odours contains volatile organic compounds that outgas and attach themselves to dust particles in the living spaces.
Many material protection and cleaning agents as well as wall paints also contain these pollutants. When selecting products, it is important to ensure that they contain as few VOCs and other pollutants as possible.
Air filters and air purifiers: from ionisation, HEPA and activated carbon filters to plants
Since pollutants in the interior cannot be completely avoided even with thorough and regular dust removal, air filters or air cleaners can provide relief. However, you should pay close attention to which technology you choose. Devices that work with ionisation require little maintenance, have low power consumption and filter even the smallest particles from the air. But at the same time they emit harmful ozone.
Air purifiers with HEPA filters can filter neither all gases and odours nor the smallest particulates particles from the air. Unlike ionisation devices, however, they work with low pollutant levels.
Cleaners with activated carbon filters also do not emit any other pollutants. They can even filter odours and gases from the air. However, the filters have to be changed comparatively frequently.
Biological air filters are an alternative. At present, several innovations are entering the market that clean the air with the help of plants. Although they draw in the air specifically to achieve the greatest possible effect, they work very energy-efficiently. Some of them require no electricity at all. In addition, they are particularly low-maintenance and do not lead to undesirable side effects. However, since these are relatively new technologies, reliable conclusions about their actual filter performance can hardly be drawn so far.
(Image: Stilfehler/Wikimedia Commons)
