In fact, most of us are likely to be experiencing more pollution inside, according to the Environmental Protection Agency^².

It says there can be two to five times the quantity of pollutants in a building than outside - and ranks indoor air pollution among the top five environmental health risks to people.

The World Health Organisation^² believes that 3.8 million premature deaths a year are the result of poor indoor air

This hazard to our health, comfort and performance is caused by:

• Materials^¹ used in construction and decoration, which can be long-term sources of air-borne chemical compounds.
• Energy efficiency and better insulation, which while a good thing, can have the side effect of trapping pollutants if ventilation is not good enough.
• Activities like cooking and cleaning, which lead to small particles, gases and chemicals escaping into the air.
• Fungal spores and bacteria.

Any of these factors can lead to Sick Building Syndrome, with symptoms such as eye, nose and throat irritation, headaches, fatigue and irritability, chest tightness and wheezing and skin irritation.

The need to improve the air quality in buildings - from schools and hospitals to offices and homes - has never been more urgent. Here’s how we can make a start:

Bringing clean air into a building replaces contaminated air and removes pollutants from the atmosphere.

The most obvious way to do this is by making sure windows are opened regularly. However, this comes with its own issues, as outdoor air often contains other pollutants, meaning you’re adding new pollutants to your environment.

Opening windows also isn’t possible during the colder months and can have a significant impact on the effectiveness of HVAC systems, leading to increased costs.

Where opening a window isn’t an option, measures that can support better ventilation include extractor fans, dehumidifiers, air conditioning, air bricks and indoor air purifiers. The last of which we’ll discuss in more detail later.

A vacuum cleaner with a HEPA filter will help to remove dust from carpets and soft furnishings, while micro-fibre cloths should be used to clean hard surfaces every day.

Prevention is always a good thing. Dust mites like warm, dark, and humid spaces, so rooms should be kept dry and well-ventilated to keep levels down.

By minimising clutter and insisting on a clean desk policy in work environments, pollutants and dust particles will be easier to remove.

As well as creating an attractive working environment, plants can play a small part in enhancing indoor air.

The use of greenery to improve our air became more popular after a study by NASA, which found two plants, peace lilies (Spatiphyllum ‘Mauna Loa’) and florist’s chrysanthemums (Chrysanthemum morifolium), could help reduce the levels of some indoor pollutants, including formaldehyde and benzene.

Although more recent research indicates we need a huge number of plants to truly get these benefits, there could still be a marginal advantage.

To know exactly how clean, and safe, the air is in your building, some air purifiers can provide information about air quality and will automatically activate when they detect pollutants in the air.

Not all air purifiers, or HEPA filters, are the same, however. Look for models with True HEPA filters that can filter 99.97% of pollutants with a particle size of 0.3 microns. Or even better, “medical grade” H13 True HEPA filters capture 99.995% of all particles down to 0.3 microns.

Air purifiers that combine True HEPA filters with carbon filters, which are designed to capture odours and volatile organic compounds, are extremely effective when it comes to improving your indoor air quality. Using them in partnership with the other measures we’ve discussed above, are the best way to help clean the air you breathe.