I have already touched upon smog on my blog, but it struck me as useful to look into the air purification topic as well. Why? Because we happen to spend 90 per cent of our time indoors, which means that we become what we breathe.



Do you know that we breathe in and out between 15,000 and 40,000 litres of air every day? Most frequently this is indoor air, because this is unfortunately how our lives look – during the day we move from one building to another: from home to work, to a bank, nursery, shop, cinema, public offices, restaurant, school, petrol station, hotel, beautician, train station, health centre, hospital, etc.

And indoor air can be up to 5 times more polluted than outside! What exactly do we breathe in?

Below are examples of some typical indoor air pollutants and their particle sizes in µm (micrometres):

  • dust 5-100 µm;
  • moulds 2-20 µm;
  • pet hair and dander 0.5-100 µm;
  • dust mite eggs 0.5-50 µm;
  • suspended particulate matter PM 10 2.5-10 µm;
  • suspended particulate matter PM 2.5 1-2.5 µm;
  • bacteria 0.35-10 µm;

Many analyses have shown that over 88 per cent of particles found in the air are nanoparticles, that is the ultrafine particles of 0.1 µm or less. They form naturally e.g. during fires or volcano eruptions, but can also be created by humans. They are the by-products of the aviation industry, the energy sector, motor industry (especially Diesel engines), copiers, printers, the catering industry, and the cosmetics sector. They are generated during welding, soldering, vulcanisation and polishing.


The following are used in nanotechnology: e.g. silver, gold, copper, titanium oxides, zinc, copper and iron oxides. They improve the qualities or characteristics of products, materials and goods. For this reason, they are more and more frequently used e.g. in the production of paints, creams with filters, toothpastes, chewing gums, sweets, ceramics, baby care products, deodorants, antibacterial underwear, air fresheners, tattoo inks, catalytic converters, cement, disinfectants, vaccines, wound dressings, washing machines, fridges, etc.

Their widespread application is starting to raise concerns because nanoparticles can penetrate into the human body in three ways: through the airway, the digestive system, and through the skin. Some of them are able to permeate the blood-brain barrier and cumulate in the neural system, they can damage cells, the immune system, contribute to increased free radical production, cumulate in internal organs such as kidneys and liver, and cause oxidative stress.

Honestly, it sounds a bit worrying to me.



Have you heard of the “sick building syndrome”? It is the name given to a collection of symptoms affecting occupants of a certain place (e.g. an office building). It was first identified in the 1970s.

The symptoms include, among others, headache, eye, nose and throat irritation, dry cough, dry and irritated skin, feelings of dizziness and nausea, difficulty concentrating, fatigue and hypersensitivity to smells.

The sick building syndrome symptoms can have perceptible influence on work productivity, and even result in absenteeism.

What causes the SBS? Research demonstrates that SBS symptoms are attributable to poor indoor air quality, which is the resultant of:

  • internal physical factors – dust, carpet fibres, fungal spores, moulds, plant pollen, mites, bacteria, viruses and toxins;
  • external physical factors – particles brought into the building on shoes, clothing, on animal fur and paws);
  • internal chemical factors – computer equipment including peripherals, printers, copiers, which are the source of ozone, volatile organic compounds (VOC), household cleaning products, building materials, tobacco smoke);
  • external chemical factors – exhaust fumes, chimney smoke;
  • inadequate ventilation.

In 1984, the World Health Organisation informed in its special report that the SBS affects as many as 30 per cent of all new and redecorated buildings in the world.



I have read that the correct oxygen content in indoor air should be 20 per cent. In poorly ventilated rooms, e.g. in the bedroom after the night, the oxygen level can fall to meagre 17 per cent. This actually poses a health hazard.

If oxygen deficiency is further aggravated by contaminants then no wonder that people often feel tired, in poor shape, their concentration levels fall and – as a result – their work becomes less effective.

I myself was affected by it a number of times, which sparked my interest in the topic. In our company, we use air purifiers which remove even those ultrafine particles (they happen to be Genano filters). However, moving from one meeting to another, or participating in conferences, I noticed that ventilation or air-conditioning alone are not enough. Gradual fall in energy level is noticeable.

Statistics have it that this problem is prevalent in such buildings as private homes, offices, schools, universities and nurseries.

According to World Health Organisation’s data, as many as 93 per cent of children, on a global scale, live in environments where air contamination exceeds the recommended limit values.

Indoor air quality affects asthma sufferers in a particular way. The American Journal of Respiratory and Critical Care Medicine has published research results which indicate that 65 per cent of asthma cases in school-age children could be avoided by controlling their exposure to tobacco smoke and allergens present in indoor air. By controlling biological contaminants in the air (dust particles and allergens of animal origin) asthma cases could be reduced by 55-60 per cent! Quite a lot, is it not?

I have discovered that in order to achieve that effect, the air purifier ought to be efficient enough to filter the entire air volume in the building three times per hour! In addition, in the case of asthma and allergy sufferers, who are sensitive to tobacco smoke and the smallest particles, the only purifier of any use is the one equipped with a carbon filter, which can even absorb nanoparticles of 0,0010 µm (e.g. ElixAir).

The expression “healthy atmosphere” at work, school or home does take on a new meaning when confronted with all these facts, honestly.

I will be happy to hear about your experiences and feelings about air in your homes or at work.


Smart City is a place
of happy people.

Dariusz Stasik

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