Air is a fundamental component of you and your environment. It flows over you, around you and within you. The air you breathe, the water you drink and the food you eat are the most important factors for determining how healthy you, your family, and your friends are everyday.
People rarely place as much attention on air quality, even though we can only survive a few minutes without breathing. The average person breathes 7 to 8 litres (2 gallons) of air per minute which is approximately 11,000 litres (2,900 gallons) of air per day. If the quality of air you are breathing is poor, then it is going to absorbed into your body very quickly, and the immediate and long term consequences can be profound.
Physically, air is a mixture of nitrogen, oxygen, water vapour, and numerous other gases which are small by proportion, but very influential to the health and well-being of the people, animals, plants and organisms that need it.
The balance of different gasses in a given volume of air is continually fluctuating as the air flows through all the processes, organisms and objects in the environment. Air picks up new molecules, and deposits some existing molecules on all the surfaces with which it comes into contact.
Many of the good, bad and inert components of the air are absorbed in very small quantities into your lungs and fine membranes in areas such as your nose, mouth and eyes. The precise concentration of these molecules can profoundly impact how you think, feel and live on a minute to minute basis of every single day of your life.
Polluted air has relatively high concentrations of toxic chemicals. It is perhaps arguable that all air is polluted at least, in very small concentrations. Polluted air in the context of you and your immediate environment is a very definite reference to much higher levels of toxins in the air you breathe and the potential harm that it can do to you and your body.
Indoor Air Pollution
On average people in the UK spend over 90% of their time indoors. The quality of air that we breathe inside the home or in our workplace has never been more important. This issue is particularly problematic for people living in more densely populated towns and cities.
The majority of air pollution comes from synthetic materials and human activity.
Have you ever experienced the smell of a new carpet or a freshly painted bedroom? These smells are caused by a process called 'off gassing' whereby synthetic materials release chemical vapour or Volatile Organic Compounds (VOC's) into the air for a prolonged period after their manufacture or during the use of many common household cleaning products.
There is a growing body of research that links outdoor air quality with indoor air quality. Polluted outdoor air is drawn inside via ventilation systems or gaps in the building fabric.
Evidence has also highlighted that indoor air pollution can be high even when outdoor air pollution is low - this demonstrates that sources of indoor air pollution are significant.
Common Indoor Air Pollutants
Carbon Monoxide and Carbon Dioxide - from combustion within appliances such as gas hobs, heaters and boilers, and open fires.
Bacteria and Viruses - microorganisms from humans, pets and decaying materials.
Biological Allergens - house dust mites, insects, moulds, and animal dander from pets.
Formaldehyde - a very common toxin found in many building materials, furniture (composite woods), fittings and house hold cleaning products. Present in the glues and resins of composite wood furniture, fittings, fabrics, glues, urea-formaldehyde foam insulation among many others.
Polycyclic Aromatic Hydrocarbons (PAH's) - produced by the incomplete combustion of fuels such as gas or coal.
Volatile Organic Compounds (VOC's) - organic chemicals that have a high vapour pressure at usual room temperature. Examples include benzene, methylene chloride, napthalene and 'essential oils' such as terpenoids - from a wide variety of household, consumer and personal care products.
Oxides of Nitrogen (NOx) - from combustion appliances such as gas hobs, open fires or central heating boilers. The most significant is nitrogen dioxide which causes inflamation of the lining in the lungs which is particularly problematic for asthma sufferers. Children and older people are particularly vulnerable.
Particulate Matter (PM10's) and Fine Particulate Matter (PM2.5's) - Particulate Matter with a size of 10 micrometers or less can be absorbed into the deepest parts of the lungs where they can become trapped and remain for years.
Ozone (O3) - from electrical appliances. Ozone causes damage to mucous and respiratory tissues in people and animals.
Phthalates - a group of industrial chemicals used to soften PVC plastic materials and as solvents in cosmetics and consumer products. Toxic to liver, kidneys and reproductive system.
Polychlorinated Biphenyls (PCB's) - and other persistent organic compounds - from old paints, mastics and sealants, plastics and flame retardants.
Insecticides - from timber treatment and pesticide sprays
Mineral dust and fibres - from building and insulation materials
Second hand smoke - from cigarettes and tobacco (formaldehyde, benzene, ammonia, hydrogen cyanide)
Sources of Indoor Air Pollution
All indoor environments contain materials and sources which cause air pollution however, some buildings are more polluting than others.
Glues, solvents and chemical additives - glues, resins, plasticisers, fillers, solvents, stabilisers and preservatives. Commonly used to bond MDF and chipboard, treat woodwork, bond synthetic fibres in carpets and thousands of other uses.
Paint and decorative coatings - high VOC content particularly where non-water based solvents are used.
Furniture, fabrics and carpets - man made wood materials, synthetic polymer fabrics and carpets
Cooking hobs, heaters and open fires - gas cooking hobs and heater emit a range of pollutants from hydrocarbons to carbon monoxide.
Cleaning and cleaning products - many common cleaning products have very high VOC content. Vacuuming can also disturb settled dust which can contain micro particles and contaminants.
Pet hair and human skin cells - pet hair is known to cause irritation to people with allergies and human skin makes up a substantial portion of house dust. Both are sources of biological allergens.
Damp and poorly ventilated rooms - damp and poorly ventilated environments foster a variety of moulds which can produce spores and toxic substances.
Open windows, ventilation systems, poorly constructed buildings - these allow polluted air from outside into the home or workplace. This is particularly problematic in urban environments or where buildings are situated close to busy roads.