At this time of year it seems like everywhere you go, people are sneezing and coughing.
What can you do to avoid catching a cold, or worse, the flu?
Some obvious ways of avoiding colds and flu
Get your annual flu vaccine
Protect your paws …
Sanitise your home …
Rhinoviruses can live on surfaces for up to 48 hours!
Be the office hygiene hero! Ensure that everything that gets touched by lots of people — microwaves, doorknobs, elevator buttons, chair armrests — is cleaned with a good disinfectant at least once a week.
And some surprising ways too!
Eat an Egg!
Use your own pen
Sleep like a baby
Sip hot tea instead …
You might think that going outside in the cold makes you more likely to ‘catch a cold’. But in fact, colds and the flu spread much more easily inside. Let us explain …
How are colds and flu spread?
Both flu and the common cold are caused by viruses, which are spread through exposure to respiratory secretions (i.e. an infected person’s sneezes or coughs). The virus can be spread through the air, personal contact (such as a handshake), or by touching contaminated objects.
How long do cold viruses remain infectious?
As you can see, cold and flu viruses can hang around indoors for up to 24 hours – and people can shed huge numbers of cold / flu viruses into the air which can in turn settle onto surfaces:
Nature’s outdoors remedy - Hydroxyls
However, outside, you’re much less likely to catch these viruses. That’s because Hydroxyl Radicals, which occur naturally and abundantly in the air outside, kill all human pathogens on contact, including cold and flu viruses.
Hydroxyl Radicals are commonly known as ‘Nature’s Detergent’, and we think they are pretty amazing!
The Environmental Protection Agency (EPA) estimates that our indoor air is nearly 5x more polluted than outdoor air. Some homes may even have 100x more pollution.
Here are thirteen common sources of indoor air pollution:
1. Chlorine bleach
2. Household cleaning chemicals, paints and solvents
3. Synthetic fragrances, perfumes and deodorizers
4. Dry cleaned clothes
5. Tobacco smoke
6. Biological pollutants
7. Pet dander
8. Carpets and upholstery
9. Building and decorating materials
11. Office and craft materials
12. Combustion pollutants
13. External pollution
Can Air Purifiers Help?
This then is the conundrum; we need air to circulate from outside to inside, but in areas with substantial external pollution that circulation continuously brings harmful outside pollution into our homes.
Outside vs Inside
Outside, Nature wages a powerful war of attrition against atmospheric pollution.
Wind disperses pollution, diluting its local effects. Natural chemical and photochemical interactions create an abundance of ‘hydroxyl radicals’ (called ‘Nature’s Detergent’ by scientists) which attack and neutralise a wide range of pollutants, and rain and snow wash pollution and its by-products out of the air.
Of course, in the urban environment, pollution can build up where it is created more quickly than nature can remove it.
Inside, the natural conditions which create hydroxyls are absent, and pollution, well, it hangs around for us to breathe it in!
What does the pollution consist of?
Before deciding on an effective strategy for reducing pollution leaking in from outside, it is necessary we understand the scope and nature of the pollution we are attempting to neutralise.
Historically, the main air pollution problem in both developed and rapidly industrialising countries has typically been high levels of smoke and sulphur dioxide emitted following the combustion of sulphur-containing fossil fuels such as coal, used for domestic and industrial purposes.
These days, the major threat to clean air is now posed by traffic emissions. Petrol and diesel powered vehicles emit a wide variety of harmful pollutants, principally carbon monoxide (CO), oxides of nitrogen (NOx), volatile organic compounds (VOCs) and particulate matter (PM2.5). Additionally, the photochemical reactions resulting from the action of sunlight on nitrogen dioxide (NO2) and VOCs create ozone.
Carbon Monoxide (CO)
CO (carbon monoxide) is a dangerous, colourless gas which reduces your blood’s ability to carry oxygen and can make you ill.
Oxides of Nitrogen (NOx)
The Committee on the Medical Effects of Air Pollution recently reviewed the evidence for the adverse health effects of NOx and concluded that:
Volatile Organic Compounds (VOCs)
VOCs include a variety of chemicals, some of which can have short- and long-term adverse health effects.
Ozone can trigger asthma attacks and cause shortness of breath, coughing, wheezing, headaches, nausea, and throat and lung irritation, even in healthy adults.
Particulate matter, also called PM or soot, consists of microscopically small solid particles or liquid droplets suspended in the air.
PM2.5 refers to what are termed “fine particles” of below 2.5 microns in diameter. The smaller the particles, the deeper they can penetrate the respiratory system and the more hazardous they are to breathe.
Ultrafine particles (UFPs) are particulate matter of nanoscale size (less than 0.1 microns in diameter). UFPs are the main constituent of airborne particulate matter. Owing to their numerous quantity and ability to penetrate deep within the lung, UFPs are a major concern for respiratory exposure and health
PM pollution can cause lung irritation, aggravates the severity of chronic lung diseases, causes inflammation of lung tissue, causes changes in blood chemistry and can increase susceptibility to viral and bacterial pathogens.
Step 1 - Reduce air leakage
Click here for a good basic guide on what can be done to both save energy (and money!) and reduce air leakage.
Simply reducing leakage won’t solve the pollution problem (reducing leakage by, say, 50%, won’t really help in pollution terms; the air inside will still be as polluted as the air outside), but the lower the leakage rate, the more effective the use of air cleaning technology will be.
Think about it this way: Sit an air cleaner, however effective, next to an open window, and it will be overwhelmed by new pollution to the point where it will have no effect. For an air cleaner to be effective, you have firstly to slow the flow of new air into a room to give it time to work.
So, reducing leakage is only the first step in mitigating the pollution problem. The second step is using an air cleaner that really works!
Step 2 – Remove or neutralise internal pollution
Having reduced air leakage, let’s look at our options for removing or neutralising polluting gasses and particulates before we breathe them in:
Can filters reliably remove or neutralise all of CO, NOx, VOCs and O3?
X No! CO, NOx, VOCs and O3 are gasses that cannot be filtered out by HEPA, Ionising (Ionic) or Electrostatic (Electronic) filters, which are all designed to filter out particulates, not gasses.
What about activated carbon filters?
These are sometimes suggested to remove these gasses from the air and can be implemented either as stand-alone filters or in combination with a HEPA filter to capture the larger particulates.
There are many problems with using this type of filter to address outside air pollution:
X So, all in all, activated carbon filters are not effective as a solution for removing gaseous pollutants.
OK, how about HEPA filters?
The ‘gold standard’ for particulate filters is the High Efficiency Particulate Air (HEPA) filter. Filters meeting the HEPA standard remove 99.97% of particles that have a size 0.3 microns or larger from the air passing through them.
However, 90% of particulates in the air, including the most harmful ones, are smaller than that, so most HEPA air purifiers only catch a fraction of all particulates, and none of the potentially most harmful ones.
X Hepa Filters will only remove 10% of the particulates.
So, filters simply aren't effective at removing industrial and traffic pollution?
Correct. And air filters don't work well in the real world anyway! Not only are there no suitable and affordable filters for the purposes we require, the unfortunate fact is that portable air filtration devices, of whatever type, are not very effective at treating any kind of pollution.
All portable air filters share the same fundamental shortcoming; even if they do filter the air passing through them effectively, they only clean that limited amount of air that passes directly through them, not all of the air in the room. You can find out more here.
Then along came Airora…
Let us return to where we started, outdoors.
Outside, Nature wages a powerful and successful war of attrition against atmospheric pollution by employing natural chemical and photochemical interactions to create an abundance of ‘hydroxyl radicals’ (known as ‘Nature’s Detergent’ by scientists) which attack and neutralise a wide range of pollutants.
Find out more about how Airora breaks down harmful gasses and vaporises key ultra-fine particulates that are too small to be trapped by HEPA filters here.
Hay fever is a type of allergic rhinitis caused by pollen or spores. Allergic rhinitis is a condition where an allergen (something that causes an allergic reaction) makes the inside of your nose inflamed (swollen).
Hay fever usually occurs in spring and summer, when there is more pollen in the air. Trees, grass and plants release pollen as part of their reproductive process. Mould and fungi also release tiny reproductive particles, called spores.
People with hay fever can experience their symptoms at different times of the year, depending on which pollens or spores they are allergic to.
Hay fever symptoms vary in severity and your symptoms may be worse some years than others, depending on the weather conditions and the pollen count (see below). Your symptoms may start at different times of the year depending on which types of pollen you are allergic to.
The symptoms of hay fever include:
Less commonly, you may experience:
Hay fever is an allergic reaction
Hay fever symptoms are caused by protein molecules in pollen grains. The immune system ‘over-reacts’ to these allergens, which it manifests in the form of an allergic reaction. Immune molecules known as Immunoglobulin E are produced and these cause the release of the inflammatory chemical called histamine from mast cells (a type of immune cell).
It is histamine that produces the characteristic symptoms of an allergic reaction.
A non-allergic person’s immune system will not produce this reaction on exposure to allergens in pollen.
Hay fever and everyday life
Research shows that students’ academic performance may be affected during exams, given that the exam season usually coincides with the height of the pollen season.
How common is hay fever?
Hay fever is a relatively new disease, first described in 1819. It took nine years to accumulate enough hay fever cases to present a paper on this new condition to a medical journal. Now hay fever is much more common, particularly in the UK, which has more cases than anywhere else in the world (followed closely by Ireland, New Zealand, Australia and Canada). Hay fever:
Hay fever and asthma
If you have asthma, your asthma symptoms may get worse when you have hay fever. Sometimes, asthma symptoms only occur when you have hay fever. These symptoms include:
Hay fever symptoms are likely to be worse if the pollen count is high. The pollen count is the number of grains of pollen in one cubic metre of air.
Air samples are collected in traps set on buildings two or three storeys high. Taking samples from this height gives a better indication of the pollen in the air from both local and distant sources. Traps on the ground would only collect pollen from nearby trees and plants.
The air is sucked into the trap and the grains of pollen are collected on either sticky tape or microscope slides (glass plates). The pollen is then counted. Samples are usually taken every two hours, and the results are averaged for a 24-hour period.
The pollen forecast is usually given as:
Hay fever symptoms usually begin when the pollen count is over 50. The pollen count is usually given as part of the weather forecast during the spring and summer months.
Which pollens are you allergic to?
Spores that cause hay fever can come from:
When is there most pollen?
Different trees and plants produce their pollen at different times of the year.
Depending on which pollen you are allergic to, you may experience your hay fever symptoms at different times. In the UK:
The effect of the weather
The amount of sunshine, rain or wind affects how much pollen plants release and how much the pollen is spread around. On humid and windy days, pollen spreads easily. On rainy days, pollen may be cleared from the air, causing pollen levels to fall
During their pollen season, plants release pollen early in the morning. As the day gets warmer and more flowers open, pollen levels rise. On sunny days, the pollen count is highest in the early evening.
Confusing hay fever with other conditions
A person who appears to be suffering hay fever symptoms may be suffering from:
Alleviating hay fever
It is very difficult to completely avoid pollen or spores. However, reducing your exposure to the substances that trigger your hay fever should ease the severity of your symptoms. Follow the advice below to avoid being exposed to excessive amounts of pollen and spores.
Finally, check the pollen count regularly to know when your efforts need to be more concentrated.
Can an air cleaner help?
While numerous manufacturers of ‘air cleaners’ / ‘air filters’ claim to be able to clear pollen from the air, they can only reduce, not eliminate, the problem, because:
Pets produce dander (microscopic skin flakes that they shed), and the protein in it can cause severe allergic reactions for some people.
Pet dander is a little like dandruff flakes, only smaller; at around 2-3 microns in size it easily becomes airborne and can be inhaled.
Dander can cause allergic reactions for a long period and may persist for many months after the pet has left the house.
The origin of the allergens is in the pet’s urine, sweat and saliva. These excretions adhere to their skin, for example when they clean themselves, and become of the dander they shed.
Cat dander is the most commonly inhaled allergen after house dust mite and pollen. Other types of pet, such as dogs, mice and guinea pigs, may similarly cause allergic reactions.
Because they are so light, pet allergens are widely distributed in the air, remaining airborne for several hours before settling, only to be easily stirred up into the air again.
Clearly, the best way of avoiding pet dander is to not have a pet! However, many of us love our pets too much to do without them! In that case, there are various measures you can take to reduce your exposure, including controlling the pet’s access to certain rooms, and using an effective air purifier to neutralise the dander.
Pet allergies and your health
Pet allergies are known to play a role in:
People with a tendency to allergy (known as atopy), should avoid owning pets if possible. Unfortunately, some people who don’t initially exhibit allergic reactions, can nevertheless develop symptoms after continued exposure.
Why pet dander causes an allergic reaction
Allergens usually enter the respiratory system through the nose. Mast cells in the airways release mediators, which trigger the allergy attack. This attack is an overreaction of the body’s immune system to the invading allergens that have bonded with antibodies. Mast cells are one of the human body’s principal defences against allergens and are found in connective tissue and mucous membranes. One of its biological functions is innate immunity including involvement in host defence mechanisms against parasitic infestations, tissue repair, etc.
Pet dander is very ‘sticky’ and can stay in your hair, clothes and other belongings for long periods of time. This is why you can still suffer symptoms when you are away from the pet causing those symptoms.
The major cat related allergens are found in the cat’s sweat and saliva and the major dog related allergen is found in its saliva.
What animals cause allergy problems?
A wide range of animals can cause allergic reactions including cats, dogs, birds, mice, rats, guinea pigs, rabbits, parrots and hamsters.
Male cats shed more allergen than females, and cats shed more allergen than dogs. Horses produce very powerful allergens and old mattresses stuffed with horsehair can produce symptoms. Snakes, lizards and other reptiles, and even insects, may shed dander-like skin particles into the air.
Perhaps the best pets for a pet allergy sufferer are fish, as they are not associated with allergy!
What about hypoallergenic dogs?
Avoiding pet allergens
Before turning to technological or other solutions, careful allergen avoidance / environmental allergen control is important. For example:
And don't forget - Are you sure pet allergen is really the cause of your allergy? It could be that house dust mite, mould or pollen is the real culprit. An allergy specialist will be able to offer an allergy test to pinpoint the true allergen.
Can an air cleaner help?
While numerous manufacturers of ‘air cleaners’ / ‘air filters’ claim to be able to clear pet dander from the air, they can only reduce, not eliminate, the problem, because:
There is a long history of disease caused by inhaled particles that stretches from observations by Agricola and Paracelsus in the 15th and 16th centuries up to the present. In the 20th Century the twin scourges of asbestos and crystalline silica (quartz) exerted a terrible toll of death and disease. The bad old days when these dust related lung diseases were common are fortunately gone but as we move into the 21st century a new particle type, the ultra-fine particle, has emerged as one with a potential role in causing disease.
What are ultra-fine particles and where do they come from?
Ultrafine particles (UFPs) are particulate matter of nanoscale size (less than 0.1 μm or 100 nm in diameter). This size class of ambient air pollution particles, which are far smaller than the regulated PM10 and PM2.5 particle classes, are believed to have several more aggressive health implications than those arising from larger particulates.
There are two main divisions that categorise types of UFPs. UFPs can either be carbon-based or metallic, and metallics can be further subdivided by their magnetic properties.
UFPs are the main constituent (by number) of airborne particulate matter. UFPs arise from a range of indoor sources that including printers and copiers, cooking, tobacco smoke, vaping, candles, chimney cracks and vacuum cleaners. Those indoor sources are often considerably supplemented by the penetration of contaminated air from outside, where vehicles and industry are the major contributors.
Unlike their larger PM10 and PM2.5 brethren, UFPs that are inhaled, because they are very small, can penetrate tissue and / or be absorbed directly into the bloodstream where effects may become apparent quickly.
Exposure to UFPs, even if the underlying materials are not very toxic, may cause oxidative stress, inflammatory mediator release, and could induce heart disease, lung disease, and other systemic effects. A robust association has been observed between fine particulate levels and both lung cancer and cardiopulmonary disease.
The exact mechanism through which UFP exposure leads to health effects remains to be fully understood, but effects on blood pressure may play a role. It has recently been reported that UFP is associated with an increase in blood pressure in schoolchildren with the smallest particles inducing the largest effect.
Reducing exposure to UFPs indoors
Standard HEPA filters as fitted to almost all air cleaners only collect particles down to around PM2.5 although specialist HEPA filters such as 'HyperHEPA clean room grade filters' can collect particles across much of the ultra-fine spectrum.
Ion generators have been found to have mediocre UFP removal performance and ultraviolet germicidal irradiation (UVGI) has demonstrated very limited or no UFP removal capabilities.
In addition, all filter-based devices, whatever the underlying technology, share the same shortcoming which limits their effectiveness. They only clean the air that passes through the device, not all the air in the room.
Then along came Airora ...
The advent of the Airora air purifier offers a new approach which promises to reduce the number of ultra-fine particles throughout a room.
In this approach, the ultra-fines are subject to in-situ oxidation by hydroxyl radicals. Oxidation by hydroxyls is known to fragment organic carbon ultra-fine particles, which typically constitute most ultra-fines indoors, changing them over time from solids to harmless gasses.
Research on this important subject continues!
Pollen allergy, commonly called hay fever, is one of the most common chronic diseases. Worldwide, airborne allergens cause the most problems for people with allergies. The respiratory symptoms of asthma, which affect approximately one in twelve people, are often provoked by airborne allergens.
Although the number of people suffering with an allergy has increased in the last few decades, there is more education and a greater understanding of the immense impact that allergies have on our lives, from allergy symptoms to causes to treatments.
There is no clear explanation for the increase in allergies; however there are two main theories. The first theory is that awareness and diagnosis have improved in recent years and the second is that the increase in general air pollution and indoor air pollution have made allergens more common.
An allergy is characterised by an overreaction of the human immune system to a foreign protein substance (“allergen”) that is eaten, breathed into the lungs, injected or touched and which otherwise does not bother most people.
This immune overreaction can results in symptoms such as coughing, sneezing, itchy eyes, runny nose and scratchy throat. In severe cases it can also result in rashes, hives, lower blood pressure, difficulty breathing, asthma attacks, and even death.
People who have allergies often are sensitive to more than one substance. Types of natural allergens that cause allergic reactions include:
Allergy is not necessarily the same as sensitivity or intolerance to a substance. This is particularly so in the area of food where, for example, lactose intolerance is not classed as a food allergy because the symptoms do not arise from the immune system.
Scientists think that some people inherit a tendency to be allergic from one or both parents. This means they are more likely to have allergies. They probably, however, do not inherit a tendency to be allergic to any specific allergen. Children are more likely to develop allergies if one or both parents have allergies. In addition, exposure to allergens at times when the body’s defences are lowered or weakened, such as after a viral infection or during pregnancy, seems to contribute to developing allergies.
Each IgE antibody is specific to one particular substance. In the case of pollen allergy, each antibody is specific for one type of pollen.
IgE is special because it is the only type of antibody that attaches tightly to the body’s mast cells, which are tissue cells, and to basophils, which are blood cells. When the allergen next encounters its specific IgE, it attaches to the antibody like a key fitting into a lock. This action signals the cell to which the IgE is attached to release powerful chemicals, including histamine, which cause the symptoms of allergy.
The symptoms of airborne allergies are familiar to most people:
In people who are not allergic, the mucus in the nasal passages simply moves foreign particles to the throat, where they are swallowed or coughed out. But something different happens in a person who is sensitive to an airborne allergen.
In sensitive people, as soon as the allergen lands on the lining inside the nose, a chain reaction occurs that leads the mast cells in these tissues to release powerful chemicals, including histamine. These powerful chemicals contract certain cells that line some small blood vessels in the nose, causing fluids to escape and the nasal passages to swell—resulting in nasal congestion. Histamine can also cause sneezing, itching, irritation, and excess mucus production, which can result in allergic rhinitis.
The shortness of breath is due to a narrowing of the airways in the lungs and to excess mucus production and inflammation. Asthma can be disabling and potentially fatal.
Genetics: The risk of having an allergy amongst the general population is around 10-20%. However, If one parent is allergic, a child’s risk rises to 50% and if both parents are allergic, to 75%.
Age, sex, and siblings: On average, children are more likely to suffer from allergy than adults (children can sometimes ‘grow out of’ allergic disease) and the onset can occur at any age. More boys than girls have atopic asthma and hay fever, although this difference reduces in adult life. Children from large families and those with older siblings are less likely to develop allergies, probably because they are more exposed to childhood infection, which makes the developing immune system less likely to over-react to an allergen.
Early-life, or extreme/sudden, allergen exposure: It has been suggested that exposure to allergens like cigarette smoke, traffic pollution, dust, pollen, mould and pet dander in early life may increase a child's risk of developing an allergy. For example breast feeding for six months or more has been shown to decrease the risk of asthma and other allergies in babies. Premature babies are also more at risk of developing allergies than full-term babies.
The most common allergic diseases
Asthma is a disease of the lungs that causes airways to become blocked or narrowed making it difficult for you to breathe. It harder to breathe in than breathe out. Asthma attacks are caused by triggers which are either allergens (like house dust mite, mould, pet dander) or irritants like cigarette smoke, traffic pollution or cold air.
Asthma attacks are usually temporary, but if an asthma episode is severe, a person may need emergency treatment to restore normal breathing. Despite the far reaching effects of asthma, much remains to be understood as to what causes it and how to prevent it.
Asthma is potentially the most serious of the allergic diseases. In the UK, for example, during 2008-9, there were nearly 80,000 hospital admissions for asthma of which nearly half were of children aged 14 and under.
Although asthma can cause severe health problems, in most cases prevention and treatment can control it and allow a person to live a normal and active life.
Hay fever (seasonal rhinitis) is characterised by itchy nose and eyes, sneezing and runny nose. In the UK it is mainly caused by exposure to grass pollen (perennial rye and timothy grass).
Perennial rhinitis persists all year round. Sometimes people with perennial rhinitis do experience worse symptoms in the pollen season. Around 50% of those with perennial rhinitis have an allergy while the rest have some other problem with their nose or sinuses.
The most common airborne allergens
The ‘Allergy Season’
If you are allergic to pollen, you will need to be aware of seasonal variations. Other allergens like house dust mite, traffic and other indoor pollution, tend to be present year-round.
The pollen season varies for different plants and, in the UK, it lasts from early Spring to late Autumn.
Then along came Airora 4-in-1 ...
The levels of allergens and lung irritants are much higher in your home than outside. Traditional air purifiers can do little to help because of their limited ability to clear the air, and keep the air clear, of all of the types of allergen and pollution which might cause you problems. Only Airora 4-in-1 treats ALL types of pollution, in a WHOLE ROOM, in seconds (no filter required!).
In the open air, 'Hydroxyl Radical Cascades' are continuously created by the complex chemical interactions that occur naturally in the atmosphere. Hydroxyls are the powerful but entirely safe and natural air cleaning agent, often referred to by scientists as 'Natures Detergent', which continuously decontaminate the air and gives 'fresh air' that clean and refreshing feel that we all love.
Indoors, the natural atmospheric ingredients that continuously create hydroxyl radicals don't exist and allergens remaining active, smells remain smelly and bacteria and viruses constantly build up in the air and on surfaces. Consequently, indoor air is generally much more polluted than outdoor air, yet until recently it has received far less public attention.
We often spend up to 90% of our time indoors (at home, work or at school), so exposure to indoor air pollution is potentially much more damaging to our health. That is why the World Health Organisation considers indoor air pollution as one of the main health threats today, and states that around 3% of the global burden of disease is directly attributable to it.
Indoor air pollution
Indoor air pollution is a complex mixture of microbes and substances in the air that are potentially harmful to health. The composition of this indoor air pollution can vary greatly depending, for example, where you live and on the contents of your home.
In a home in a non-urban setting for example, house dust mite, pollen and mould spores can be a major cause of indoor air pollution and related health problems. In a new-build home or office, fumes from paints and insulation, new carpet and furniture can significantly contribute to the pollution. Especially in industrial or built up areas, traffic and industry pollution also play an increasing part in indoor air pollution.
In our homes the build up of both bacteria and viruses in the air is much greater than outside.
Sources of pollution
Damp dusting, not just dry dusting, is needed to reliably remove dust rather than just spreading it around. Most carpets are a major reservoir for dust and for every six rooms in a house around 40 pounds of dust is generated in a single year, much of which is human skin as we regularly shed our outer layer of skin as part of a continuous renewal process.
The main components of dust which can affect your health indoors are:
Prevention of indoor air pollution
It is always better to try to prevent indoor air pollution occurring before attempting to reduce or remove it:
Where the main source of pollution is internal rather than external, it is helpful to open windows after bathing, showering or cooking so that damp and mould don't build up.
An effective air purifier can play an essential part in reducing indoor air pollution in your home or place of work. But the key word here is ‘effective’ and the unfortunate truth is that most traditional air purifiers are not very effective!
Various types of traditional air purifier focus on different pollutants, typically pollens, spores and other particles or on gaseous pollutants. Some combine technologies to address more than one type of pollutant.
But all have the same drawback, they only clean the air passing through the device and rely, to only limited effect, on a high throughput of air to draw in pollution from the ever changing air in the room. However good the filter mechanism, they will only ever clean a modest proportion of pollutants from the air in a room because constant air changes, re-contamination, re-circulation and eddy formation means that there are always significant airborne pollutants in a room which have not been drawn into the device.
Then along came Airora ...
There is now however a new generation of air purifiers of which the Airora 4-in-1 is the first (and currently only) one. These air purifiers use the naturally occurring ‘hydroxyl radical cascade’ process found in the outside atmosphere to clean internal air (and exposed surfaces) of the full range of pollutants; allergens and irritants, pollutant gasses, bacteria and viruses and smells.