We breathe in around 12,000 liters of air each day. Most of us know the basics about its composition from our school days: it's predominantly nitrogen (78%) and oxygen (21%). But what about the remaining 1%?
The air we breathe is never completely pure. It's constantly affected by various pollutants, originating from both human activities and natural processes like erosion, wind, pollen, and volcanic eruptions...
Often, unless there's a noticeable odour or visible pollution, we do not spare much thought for the air around us. However, according to a report by the European Environment Agency 1,air pollution in Europe still significantly exceeds the levels recommended by the World Health Organisation, This pollution is not just an environmental concern; it's a health hazard too, linked to the exacerbation of respiratory diseases, asthma, and even lung cancer, as well as cardiovascular diseases. Alarmingly, allergy cases have doubled in the last 20 years 2.
In 2021, across the European Union1, the following impacts were observed:
These figures prompt us to question: What exactly are we breathing, and how does air composition affect our everyday lives?
After exploring how indoor air quality can impact cognitive performance and productivity at work, the effects of indoor air quality on cognitive performance and productivity at work, our latest article broadens the scope to examine the overall effects of air composition on health.
Water is typically the third most abundant molecule in air, following nitrogen and oxygen. Its concentration varies depending on climate, location, and external environmental factors. In some cases, air can contain up to 7 grams of water per kilogram.
Humidity levels significantly influence our daily comfort. Humans generally find air with about 50% humidity most comfortable..In temperate regions, where temperatures usually range from 17 to 27°C, the optimal humidity level for our well-being is considered to be between 40% and 60%.
UDry air can be uncomfortable and even harmful to our health. It can irritate our eyes, dry out our airways, and may trigger asthma attacks. Often, the air conditioning in our offices contributes to this problem by condensing water vapor and circulating overly dry air. When the humidity drops below 30%3 it can lead to electrostatic discomfort. This means the air becomes too insulating, enhancing our perception of odours and dust.
The notorious effects of dry winds, like France's Mistral or Autan wind, are more than just folklore. We've previously discussed the health benefits of negative ions on this blog. . Conversely, positive ions can have adverse effects on the human body, including increased irritability. The phenomenon of the 'wind that drives you crazy' is attributed to an atmospheric imbalance where the wind carries high concentrations of positive ions. This, combined with the adrenaline stimulation from wind gusts and the physical effort to counteract the wind, can lead to a rise in illnesses and accidents4.
On the flip side, moisture in the air helps settle airborne particles and bacteria, thereby naturally purifying the air.
While some level of humidity is essential, too much can lead to various health problems. Overly humid air fosters the growth of microbes and encourages condensation on cooler surfaces. This often results in mould formation in our homes, leading to subsequent allergies.
Additionally, high humidity levels can cause discomfort, particularly when combined with high temperatures.
Carbon dioxide (CO2) is a fundamental component for plant life, used in photosynthesis to create organic carbon compounds (like sugars and cellulose) and oxygen. Conversely, humans and animals convert oxygen back into CO2 through respiration..
A small concentration of CO2 in air, typically less than one molecule per 1000 (0.1%), is natural and essential for life on Earth.
However, since the Industrial Revolution, human activities have significantly increased CO2 emissions. From levels below 300 parts per million (ppm) pre-industrial revolution, they have now risen to 420 ppm. Most of these emissions since 1990 have come from burning fossil fuels (70-90%) and from agriculture and forestry (about 12%)5.
These increased levels of carbon in the air have profound implications for our future and health. They contribute to global warming, with well-documented and tangible consequences. These include more frequent and severe weather events (like droughts, fires, and floods) and indirect effects such as changes in flora and fauna, longer pollination periods, and respiratory issues in vulnerable individuals, leading to a rise in allergic rhinitis and asthma cases.
When CO2 levels in the air we breathe rise, they can affect respiratory rhythms in sensitive individuals and impair psychomotor performance.
Short-term exposure to CO2 levels starting at 1000 ppm can impair cognitive functions, such as decision-making and problem-solving. Epidemiological studies have also found a link between CO2 levels starting at 700 ppm and building-related symptoms, with respiratory issues observed in children at indoor CO2 concentrations over 1000 ppm. These levels are much higher than those found in the atmosphere but they are unfortunately common in indoor environments, especially those that are densely occupied or poorly ventilated.
The following table, excerpted from an article in Environment International, outlines the health effects associated with different levels of CO2 in the air6.
Ozone levels in the atmosphere vary depending on climatic and meteorological conditions. It's notably present in higher quantities during summer pollution peaks.
Ozone, a potent oxidant, forms through various reactions energised by solar radiation and heat. It reacts with most molecules, enabling it to disinfect air and surfaces by effectively killing microbes. Additionally, ozone neutralizes unpleasant odours. Its own distinct smell, often noticed after a thunderstorm (since lightning generates large quantities of ozone), is perceived as refreshing and clean by many people, akin to the scent of bleach on the ground. In nature, ozone can be found at levels of several tens of parts per billion (ppb) during summer. Moreover, the ozone layer in the upper atmosphere plays a crucial role in protecting us from certain harmful solar rays.
Ozone acts as a powerful agent capable of breaking down cellular membranes, impacting a wide range of cellular organisms including viruses, bacteria, and human tissue, particularly within the respiratory system. It is now classified as one of the primary air pollutants. The production of ozone in the atmosphere is accelerated by a combination of air pollutants, heat, and sunlight, leading to an increase in both the frequency and intensity of ozone peaks.
Negative Ions in Air Composition
Naturally, air is filled with negative ions, ranging from a few hundred to several thousand per cubic centimeter. These 'small ions', either atomic or molecular, include the negative oxygen ion O2-, hydrogen ion H+, and hydroxyl ion OH-. In typical air, water molecules outnumber these ions, forming molecular clusters that reduce the ions' mobility and chemical reactivity. The constant production of atmospheric ions is attributed to cosmic and solar radiation, natural radioactivity, the Lenard effect7 (occurring when a water droplet bursts), and mechanical friction.
Recent studies by Australian researchers have found that forest air contains approximately twice as many ions as rural air. High concentrations of ions are also observed during intense rainfall or near waterfalls (due to the Lenard effect), as well as in mountain regions where increased exposure to cosmic and solar radiation enhances ionisation.
While the number of these ions is very small compared to the total number of molecules in a cubic centimeter of air, their presence is significant. These ions slightly increase the air's conductivity, enabling the transfer of large electrical charges not only between the ground and the upper atmosphere but also among objects and living organisms 8.
Recent studies highlight the health advantages associated with negative ions in the air9 : These benefits include enhanced circadian rhythms, reduced levels of anxiety and aggression, and a positive impact on the metabolic system.
Moreover, negative ions act as natural air purifiers. They charge airborne particles and pollutants – such as fine dust, bacterial germs, and toxic vapors – electrically, causing them to move within the Earth's electric field and gravitate towards the ground. This ionisation process effectively reduces the particle concentration in the air.
In nature, we live in:
The composition of indoor air is largely devoid of this "softly electric" environment: the quantity of ions is very low. The electric field is totally different. If the floor itself is insulated (a carpet, for example), or the soles of your shoes are (which is the case with many polymer soles), then your body is electrically insulated in a way that it never is in a natural state. In short, there's nothing electrically "natural" about the indoor environment.
In essence, the electrical aspects of an indoor environment are far from what we experience in nature.
Argon, an inert gas, is colourless, odourless, and tasteless. It has very specific applications: in fine chemicals, lighting, as a shield gas in electric arc welding methods, and even in dating groundwater. Remarkably, no known chemical compound contains argon.
While argon is harmless in low concentrations, inhaling it in large quantities can lead to dizziness, nausea, vomiting, loss of consciousness, and in extreme cases, asphyxiation, especially in confined spaces.
Radon is found in areas with radioactive soil. It breaks down into other radioactive gases that cling to particles. Despite its low radioactivity, radon poses a risk if it accumulates inside the body, such as when fine radioactive dust, carried by air currents from these soils, is inhaled into our lungs. Radon is a significant air pollutant in regions like Brittany and Switzerland.
It is challenging to list all the components of air exhaustively. In addition to hydrogen and methane, rare gases like helium, neon, and krypton also contribute. However, gases are not the only components of air.
While bacteria and viruses require water and nutrients to survive, they are also abundantly and diversely present in the air. Research in this area advanced significantly in the 2000s, driven by new measurement technologies.
Recent research from the United States reveals that atmospheric air (outside of buildings) contains over 1,800 different types of microbes. Astonishingly, each cubic metre of air comprises several hundred thousand bacteria and roughly the same number of viruses.
Many of these microorganisms mirror those found in soil, an environment more favourable for their growth. Interestingly, it seems that weather has the most significant impact on the types of microbes present in the air. Thus, air is not merely a mixture of gases; it's a living environment teeming with microscopic life.
More so than other airborne particles, the primary impact of viruses and bacteria is often associated with the spread of diseases. However, it is important to note that certain bacteria can actually be beneficial. They play a role in supporting the antimicrobial defence mechanisms of our mucous membranes10, 11,12.
Pollen, an essential component of plant life, is seemingly as natural as it gets. Yet, why do so many people develop pollen allergies? The pollen season varies by species and typically spans from spring to autumn, but it's becoming longer due to climate change. Moreover, climate change is altering the very nature of vegetation; new species are spreading into different areas, introducing unfamiliar pollen types into the air.
A recent discovery indicates that urban pollution can alter the nature of pollen, weakening its membranes and releasing smaller particles capable of penetrating deeper into our respiratory system. As highlighted in our article The Rise of Allergies: Air Pollution to Blame , respiratory allergy cases have seen a significant rise over the past 30 years. The World Health Organisation estimates that by 2050, half of the global population could be affected by allergies. This turns pollen into a significant pollutant.
Animals contribute to air composition by releasing proteins, often carried by hair and dander particles, which include allergens.Additionally, both animals and plants emit pheromones and phytohormones – hormone-like molecules that facilitate communication within the same species.
The familiar scents of plants and animal odoursoriginate from these hormones and the natural volatile organic compounds they release. These compounds are now widely used in the production of essential oils for room fragrances. However, caution is advised as excessive concentrations of essential oils can be detrimental to health.
It is rich in negative ions, particularly due to the Lenard effect, where electrons are stripped from water droplets as they burst (as previously mentioned). Sea air is also abundant in mineral salts, including microparticles of sea salt. These particles often contain trace elements like iodine, varying with their composition and water content13.
Forest air composition is naturally influenced by the trees inhabiting it. This includes ions, pollens, aromatic compounds, soil bacteria, and plant microfibres.
In dry regions, the air can be heavily loaded with mineral particles from wind erosion of the soil. The exact implications of these particles, and in what concentrations they become harmful, are not yet fully understood. In urban areas, these particles often carry chemical pollutants from combustion processes, such as hydrocarbons and heavy metals.
In essence, air composition is incredibly diverse, varying in a thousand different ways.
Firstly, let's consider acoustic waves.
The air is a medium that carries the melodies of birdsong, the soothing rhythm of waves, the harmonies of music, as well as the more disruptive sounds of urban life, like street noise and the footsteps of an upstairs neighbour. Ultrasound, typically quiet and innocuous, has been associated with reports of migraines, nausea, and dizziness following prolonged exposure to intense levels 14.
As previously discussed, the Earth's electromagnetic field interacts with the natural electrical charges in the air while cosmic electromagnetic waves ionise it. Both the field and these waves form an integral part of our environment. There are theories suggesting that our bodies might emit their own electromagnetic field 15. ndeed, ions play a crucial role in many of our physiological processes, and our bodies are electrically conductive. Although the topic of electro-sensitivity often arises in discussions about pollution, the interaction between our electromagnetic environment and our bodies remains under-researched.
Traditional Indian, Chinese, and Japanese medicine speak of an energy (though 'energy' may not be the precise term) known as Qi, Ki, or Prana. This energy is believed to flow both within our bodies and through the air. This 'invisible energy', sometimes referred to as 'bioenergy', has yet to be fully explained by science. However, some Western laboratories have managed to measure the manifestation of Qi during Qigong masters' practices (a Chinese health exercise designed to enhance Qi circulation within the body) 16.
Idéogramme chinois du Qi
Prana en Sanskrit
The air's rich and complex composition, constantly changing, encompasses numerous elements, some elusive, that can interact with our bodies and potentially impact our health.
An increasing portion of humanity resides in urban areas where the air is often polluted by various human activities. This includes emissions from industry, transportation, and heating systems. We have previously discussed trends in pollen and the influence of the inner city on our electrical environment. Additionally, there are other pollutants that are particularly characteristic of contemporary urban living.
Volatile Organic Compounds (VOCs) encompass much more than just the fragrance of flowers. They form a vast family of gases, many of which are present in our indoor air, emitted by items like wall paints, flooring, furniture, various objects, and household products. Some VOCs are classified as known or probable carcinogens. The emission rates of VOCs from materials and furniture can vary significantly over time, decreasing rapidly in the initial weeks before diminishing to trace levels. However, accurately determining the health impact of these residual traces of numerous organic compounds remains challenging. Additionally, these gases can react with other air pollutants, such as ozone, to form new gases or nanoparticles.
These organic compounds can also be semi-volatile. This means they can exist as micro-droplets suspended in the air. These droplets, along with other air particles, act like sponges, attracting and accumulating various chemical compounds and potentially increasing their harmful effects on our health.
Micro-organisms are prevalent in indoor environments. Conditions such as high temperatures, humidity, and elevated levels of CO2 promote their growth. Ventilation in modern buildings is often inadequate as the emphasis has been on energy efficiency through reduced heat loss, neglecting the effects on indoor air quality.
Recent studies indicate that “dampness and indoor mould indicators affect up to 21% of European homes, up to 27% of homes in Northern Europe, up to 47% of American homes and 12–78% of New Zealand homes”17. Mould is a significant source of indoor pollution and a key contributor to respiratory diseases.
Similar to the plants mentioned earlier, moulds release spores into the air for reproduction, and these spores are allergenic. Furthermore, the air indoors also contains bacteria and viruses from human respiration. Sampling above door and window frames in homes reveals that indoor air carries various unhygienic germs. Although natural air is rich in micro-organisms, the type found indoors differs significantly: indoor air is laden with germs that are generally best avoided.
The term 'particulate matter' encompasses a wide array of components found in the air. This includes micro-organisms, micro-droplets of semi-volatile organic compounds, combustion particles from engines and heaters, agricultural spray particles, and more.
These particles, most of which are submicron in size, infiltrate buildings through both natural and mechanical ventilation systems. They add to the array of particles generated by indoor activities like cooking, burning candles, wearing clothes, using various furniture and coatings, as well as from human and animal bodies, dust mites, and so on.
In conclusion, our predominantly urban lifestyle, often confined to enclosed spaces, significantly alters the air we breathe. Regrettably, in these spaces where we spend around 90% of our time, we encounter higher levels of CO2, volatile organic compounds, particles, and micro-organisms such as mould spores than we do in natural air.
Air is a rich and complex environment, an amalgam of chemical, biological, and physical elements. Our bodies not only react to it but also interact with it in myriad ways. In the realm of air filtration and purification, the focus often lies on stripping away anything that isn't part of the basic 'nitrogen + oxygen + argon' mixture we learned about in chemistry. While this might be healthy, one wonders if it is sufficient for our overall well-being and health.
In laboratories, when concocting a blend that represents an urban air profile, scientists often refer to it as a 'soup'. Intriguingly, each of us inhales around 12 kg of this 'soup' daily. We aspire to inhale kilos of good soup – healthy and fresh, with the perfect balance of moisture, a pinch of salt, gently ionised, perhaps even iodised or infused with the scent of lime blossom. A soup that is both light and nourishing, calming and energising.
Natural environments are rich in negative ions. This is precisely the principle on which the air ionizer is based on. However, do you know how this technology manages to capture the pollution particles contained in the indoor air to purify your home?
In December 2019, a respiratory virus of the Coronavirus family appeared in the Wuhan region of China and has now spread to all continents.
Purifying indoor air while protecting your health and the planet is possible! Say goodbye to filters and make way for negative ions: choose an eco-responsible air purifier that will easily reduce energy and resource consumption.