How to improve indoor air quality

If you thought you could hide from smoke and smog indoors, you've got another thing coming. Laura Sevier takes a look at the problem of in-house pollution, and offers advice on what you can do to clear the air

So much for home sweet home. When it comes to indoor air quality, the chances are you’re better off wandering the fume-filled streets of London than sitting at home in front of the telly.

Take your favourite sofa, for instance. Did you know that particles of the fabric can abrade and be taken up by your nose, mouth and lungs? According to German chemist Michael Braungart, co-founder of Cradle to Cradle design, the fabric is likely to contain ‘mutagenic materials, heavy metals, dangerous chemicals, and dyes that are often labelled as hazardous by regulators – except when they are presented and sold to a customer’. Braungart has carried out ‘off-gassing experiments’ on everyday products such as carpets, plastic toys and electric shavers to analyse their toxic gaseous emissions. Some of the worst offenders include vinyl wallpaper and flooring, laser printers and photocopy machines (the toner dust can be easily inhaled), glues, paints and household appliances such as TVs and washing machines. His verdict? ‘Indoor air is much worse than outdoor London air,’ he says. ‘Inside, you have chemicals in a sealed building.’

It’s a view supported by a growing body of scientific evidence. The US Environmental Protection Agency (EPA) first blew the whistle on poor indoor air quality in 1986; the UK’s Building Research Establishment (BRE) published devastating findings in 1996. And yet, while there are European mandatory standards for some pollutants in ambient (outdoor) air, still there is none for indoor air.

We spend much of our lives in buildings, be they homes, offices, schools or shops. Studies from Europe and the US show we spend an average 90 per cent of our time indoors. We are what we breathe. Whatever is in the air ends up in your body, so good quality air is of vital importance.

Most indoor air pollution comes from sources inside the building. As Braungart’s studies show, nearly everything we use sheds particles or gives off a range of gases, particularly when new. The stuff and staples of daily life – carpets, upholstery, manufactured wood products, electronic devices and cleaning products – emit volatile organic compounds (VOCs) including formaldehyde. VOCs are liquid or solid substances that turn into or emit gases at room temperature (a process known as off-gassing). They are the most common type of gases found indoors, and they are bad news. Adverse health effects can include eye, nose and throat irritation, headaches, loss of coordination, nausea, and damage to the liver, kidneys and central nervous system. Some are known to cause or are suspected of causing cancer in humans.

Dr Derrick Crump, a BRE specialist in indoor air quality, says indoor concentrations of VOCs are typically 10 times higher than outdoors. To make matters worse, the gases get trapped indoors. Thanks to the airtight and energy efficient nature of many modern buildings, there is less ventilation in the form of drafts. Also trapped can be chemical contaminants from the outside (such as pollutants from exhaust fumes), which can seep through windows or poorly located air intake vents.

At worst, high levels of contamination can cause ‘sick-building syndrome’. Headaches, dizziness, disorientation, fatigue, difficulty concentrating, eye, nose and throat irritations are all symptoms. Newly built or remodelled buildings, in particular, tend to off-gas a higher level of chemicals than older ones.

What you can do...

  • Freshen the air - naturally

Unless you live next to the M25, the cheapest and most effective way to allow fresh air in and toxic air out is to open a window. Ban air ‘fresheners’, a source of VOCs, and use natural odour-eaters such as a bowl of baking soda or naturally fragranced alternatives (see Avoid using perfumes, deodorants or products containing ‘parfum’, a word which hides the identities of as many as 100 potentially persistent or allergenic chemicals.

  • Clear out cleaning chemicals

Recent studies have linked cleaning sprays with a new onset of asthma in adults and linked cleaning products, when used by pregnant women, to persistent wheezing in their offspring in early childhood. Use a range based on natural plant ingredients or experiment with simple cleaning solutions made from lemons, vinegar and baking soda.

  • Breathable particles?

Dust is just dust, right? Wrong. A 2002 Greenpeace analysis of house-dust samples vacuumed from 100 UK homes showed that hazardous chemicals such as phthalates, brominated flame retardants, alkylphenols and organotins were widespread contaminants. Regular cleaning can help keep levels of breathable particles down along with dust mites, pollen and other allergy-causing agents. Keep humidity to a minimum to discourage the growth of mould which has the potential to cause allergic reactions when inhaled.

  • Plant power

Living, green plants can remove toxic chemicals including formaldehyde, benzene and carbon monoxide from the air, according to a two-year study by NASA scientists. The following plants are particularly effective: areca palm, lady palm, rubber plant, dragon plant, English ivy, peace lily, gerbera daisy, snake plant, spider plant, weeping fig.

  • Contaminated carpet

Carpets act as a reservoir for dust, which leads to a build-up of dust-mite allergen, an important trigger for asthma and other allergies. They also trap toxic pollutants. A 2001 Greenpeace UK report, ‘Poisons Underfoot’, found that new carpets contain significant levels of hormone-disrupting, brominated flame retardant BDE-209, the pesticides permethrin and tributyltin (an immune- and reproductive-system toxin) and formaldehyde. Vinyl (PVC) floors, made with phthalates, a hormone-disrupting chemical also linked to asthma and allergies in children, are no better. As a general rule, choose natural fibre carpets and rugs made from organic wool or cotton, coir or jute, instead of synthetic carpets (typically made of nylon or polyester), though check they haven’t been treated with unnecessary chemicals or glues (see for suppliers). FSC-certified wood flooring is another option. If you do have a carpet, avoid toxic carpet cleaners – use a steam cleaner instead. Take off your shoes to keep dirt and bacteria from the streets at bay.

  • What not to paint with

Conventional paints can include acrylic, polyurethanes, PVC and VOCs. When they off-gas, the fumes are likely to include the emissions from VOC solvents. Choose natural and non-toxic water-based or clay-based paints instead. Check that it is ‘solvent-free’.

  • Electronics

Ban electrical appliances from the bedroom. A computer, for instance, contains toxic gases, toxic metals (such as cadmium, lead and mercury), acids, plastics, chlorinated and brominated substances. The dust from some printer toner cartridges has been found to contain harmful substances such as nickel and mercury. Greenpeace has an online ‘Guide to Greener Electronics’ which ranks the top manufacturers.

  • Protect babies and children

Expecting a child? Go easy when creating a nursery. Often people paint walls and put in new carpets and curtains – so when the baby arrives it ends up in a room full of off-gassing. Myriad Toys ( sells handcrafted natural wooden toys in waterbased colours, finished with natural oil blends.

  • Bedding

Cut down on off-gassing in the bedroom – Greenfibres ( sells chemical-free natural latex, coir and wool mattresses and organic cotton bedding. See for more suppliers.


Tips from an eco-builder

For better indoor air quality, Stroud-based eco builder Nick Skinner recommends:

  • Painting with water-based or clay-based paints, such as earthclay.
  • Using real, unprocessed wood, instead of MDF and laminated wood.
  • Finding second-hand furniture (in order to minimise off-gassing).
  • Use old vintage fabrics to make curtains.
  • Older buildings are in many ways better than new - the materials used are often locally-sourced, such as limestone and decent wood. 'There are no weird finishes and they're naturally ventilated as they tend to have a few draughts,' Nick says.


For more information

What's in this Stuff? (Rodale, £11.99) and Living Dangerously (Newleaf, £12.99) by Pat Thomas

Squeaky Green: The Method Guide to Detoxing Your Home (Chronicle, £9.99) by Eric Ryan and Adam Lowry.

This article first appeared in the Ecologist November 2008

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