For us to feel well, the air we breathe must have the right composition. The components of the air are crucial to the health of the respiratory system. Unfortunately, air pollution is one of the biggest civilisation scourges we have to contend with (see Causes of smog). Let us remember that even low concentrations of inhaled pollutants can reduce the quality and length of our lives. The composition of inhaled air is of critical importance for health.
In short: air is the mixture of gases and aerosols that make up the Earth’s atmosphere. This has changed over the centuries, but at present the concentration of air constituents remains relatively constant. In atmospheric air, we distinguish between solid particles and those whose presence varies depending on weather, environmental and civilisation factors. These include, for example, water vapour, carbon dioxide and the infamous sulphur dioxide (SO2), which is an asphyxiating and highly toxic gas. Its concentration depends on geographical location, industrial development and the time of year. It is difficult not to mention at this point that the main source of SO2 emissions into the atmosphere is the burning of fossil fuels.
Pure atmospheric air contains elements such as nitrogen, oxygen, argon and carbon dioxide. The most important of the gases is – of course – oxygen, which is involved in all physiological processes in the human body. Of course, it is not only us humans that need cellular respiration. Without oxygen, animals and plants would not survive either. In the air, we also find other chemical compounds: hydrogen, neon, helium, methane, krypton, xenon, ozone, iodine, mineral and organic suspended matter, such as plant spores, as well as poisonous gases and dust.
The matter seems clear, but let us list those components of the air that threaten our health. These are mainly industrial, household, mineral (dust, soot) and harmful oxidation products of various combustible materials. The combustion of fuels is the primary source of atmospheric pollution. As a result, we inhale:
Fine dusts are very dangerous and equally insidious. They have such a small particle size that the human eye is unable to see them (less than 2.5 micrometres in diameter). These particles penetrate unhindered into the human respiratory system, then into the bloodstream, Therefore, it is worth remembering that the average annual concentration of fine dust is 10 μg/m3 (micrograms per cubic metre). However, it must not exceed 25 μg/m3 per day (WHO).
Let us also be careful during the barbecue season! It is difficult to defend ourselves against harmful air components – after all, we are not going to hold our breath. However, it is always a good idea to invest in home dust sensors and also to check the automatic measurement data (available here). These give the current composition of the air, updated every hour. It’s good to know what you’re up against.
The percentage composition of the gases in the inhaled air looks like this: 78% nitrogen, 21% oxygen, 0.04% carbon dioxide and 1% other gases. The percentage distribution of elements in exhaled air is already slightly different, as the value of carbon dioxide increases: 78% nitrogen, 17% oxygen, as much as 4% carbon dioxide and 1% other gases.
Let us recall that the air we breathe every day is full of pathological substances, i.e. substances that should not be there. These are mainly pollutants from human activity: chimneys, car exhausts, and factories. Dust and harmful gases wreak havoc on the tissues of living organisms.
Importantly, pollutants from the outdoors are also transferred indoors, so it is virtually impossible to protect against them 100%. By breathing in smog and exhaust fumes, we damage the respiratory system (especially the lungs and bronchi), the circulatory system (heart, arteries) and the nervous system (cells, brain). Contaminated air promotes cancer, and causes hypertension, conjunctivitis, asthma and other severe ailments. It also has disastrous effects on the health of pregnant women and on foetal development (birth defects). Therefore, air quality is not a distant topic for militant environmentalists, but a matter of importance for every one of us. A matter of life and death.
For this purpose, specialised room and outdoor meters are used. The usefulness of these devices is enormous, as they provide a great deal of knowledge about what air components are entering our lungs and in what quantities.
Another interesting environmental campaign is that of the Polish Smog Alert under the slogan: See what you breathe. It is based on the fact that in selected towns and cities – the most threatened by smog – so-called artificial lungs will appear. This is a mobile two-metre installation that travels around the country. It indicates the level of air pollution in the most illustrative way – the mobile lungs change colour over time. At first, they are white, after a few days they become grey, graphite and finally pitch black. The lungs are made of a translucent material. Rear fans let air pass through them, mimicking human breathing. Through this demonstration, villagers and townspeople can see how polluted their towns and cities are. The project aims to encourage the replacement of old boilers (fossil fuels) with more environmentally friendly heat sources that will improve air composition.