But there is another way that potentially dangerous chemicals spread through our homes - in the air we breathe.

What's in our indoor air?

Although taking a gulp of fresh, clean air is one of the simple pleasures of life, many Australians spend 80 to 90 per cent of their time indoors, including the workplace and home. It makes sense, then, to ensure the air we breathe at home and work is fresh and clean.

What is in the air we breathe inside our homes depends on:

• how well we ventilate our houses
• the furniture and floor coverings we have inside them
• how clean we keep them
• the paints and wood treatments we use on walls, furniture and floors
• what we use to control insect pests and to clean our homes.

Here are some common pollutants of household air:

Formeldehyde

Some materials, such as the particle board that modern kitchens and some furniture is made of, emit chemicals. The chemical formaldehyde escapes from particleboard, for example.

Formaldehyde contributes to allergic reactions, sore and watery eyes, nose irritation and inflammation. At high concentrations, or with repeated exposure, formaldehyde causes headaches and chronic respiratory complaints similar to the common cold. It has also been known to cause nausea, allergies and dermatitis.

Volatile Organic Compounds (VOC)

VOCs are commonly found in the air inside our homes.

They are released from:

• the paints, varnishes, lacquers, adhesives and finishes we use on our furniture, floors and walls unless they are the newer environmentally safer paints and finishes which have lower or no concentrations of VOCs
• many cleaning products, including detergents
• some personal care products and make-up also emit the compounds.

VOC's can:

• cause headaches
• irritate the eyes, nose and throat
• may be implicated in some more serious diseases.

We can avoid VOCs:

• by avoiding products that contain them 
• by ventilating our homes by opening doors and windows if we use products containing VOCs.

Dust

Dust can be a bewildering mix of materials such as dirt brought in from outside (commonly on our shoes), the microscopic mites that live in dust (dust mites, which feed on particles of skin we shed), bacteria, chemicals and mould.

Dust:

• - irritates our nose and throat
• - can cause headaches
• - can aggravate asthma, bronchitis and other respiratory conditions.

Dust in the house is best removed by:

• - vacuuming floors
• - dusting surfaces with a microfibre cloth which, unlike a rag or conventional duster, takes hold of the dust it comes into contact with; dusters simply force dust into the air from where it settles out onto the surfaces you have just cleaned.

Mould

Moulds are tiny, living things found in moist areas.

They:

• - irritate asthma and respiratory disorders
• - cause coughs, sore throats and nasal congestion
• - are similar to dust mites in their health impact.

Adequate ventilation is part of the solution, such as installing an extractor fan in the bathroom and opening windows.

Air your pillows, doona or blankets at least every two months to reduce the build-up of mound and bacteria.

Ventilate your home

In poorly-ventilated homes, indoor air can be more contaminated than that outdoor.

That's because chemicals exuded by the materials that furniture is made of, by fresh paint, varnishes and wood stainers and by home cleaning products, as well as dust, find it difficult to move out of buildings with poor ventilation.

The cheapest and easiest way to improve indoor air quality is to let more of the outside air in:

• - open windows when you are at home to allow fresh air to flow through the house
• - if you use an air conditioner, be sure to have it serviced regularly by a professional
• - if you have concerns about the ventilation in your office speak to your co-workers, manager or occupational health and safety officer.

Reduce your use of pest control products

We're used to hearing about pesticides in farming, however those we use against flies, mosquitos, cockroaches and other flying things in the house can be just as injurious to our health.

Insect sprays and powders pollute the air we and our children breathe and can leave residues throughout your house. It is particularly important to avoid their use in the kitchen where they may settle on surfaces and utensils we use for food preparation.

Use milder cleaning products

Replace harsh chemical cleaners with simple, non-toxic cleaning products like vinegar, lemon juice, bicarbonate of soda and water.

Choose less-toxic cleaning products from your store.

Avoid air fresheners

Air fresheners are made up of solvents, artificial fragrances and perfumes and do nothing more than cover up a smell.

Opening a window or using an extractor fan is the most effective way of removing a bad smell.

Try to identify the source of constant smells and clean them up.

Select a non-polluting floor surface

Synthetic carpets and their underlay can emit VOCs into your home for a long time after installation:

• because they were installed using glues containing the chemicals
• some carpet may have been treated with stain-resisting chemicals, flame retardants and pesticides that emit VOCs.

When deciding on a new floor surface consider using timber, ceramic or cork flooring. If selecting a carpet, consider natural fibres such as wool, cotton, coir and jute.

If you do select a synthetic carpet, ask the company laying your carpet to air it in their warehouse for two days prior to installation.

Use living plants to filter the air

Researchers at the University of Technology, Sydney, have found the Kentia palm and the dwarf Queensland Unbrella Tree reduce to negligible levels the volatile organic compounds in the inside household air we breathe. Another species known to be effective in the filtering of air is the spider Plant.

VOCs, which are inhaled, are found in many common household chemical products and furnishings.

Any indoor plant will clean air by passing it through its leaves, however indoor plants on the following list are regarded as the most effective:

• Bamboo Palm (Chamaedorea seifrizii)
• Boston Fern (Nephrolepis exaltata var Bostoniensis)
• Dwarf Date Palm (Phoenix roebelenii)
• English Ivy (Hedera helix)
• Florist's Mum (Chrysanthemum morifolium)
• Gerbera (Gerbera jamesonii)
• Kimberley Queen (Nephrolepis obliterata)
• Rubber Plant (Ficus robusta)
• Areca Palm (Chrysalidocarpus lutescens)
• Corn/Happy plant (Dracaena fragrans var Massangeana)
• Dracaena 'Janet Craig' (Dracaena deremensis var Janet Crai)
• Schefflera/Umbrella Tree (Brassaia actinophylla)
• Peace/Madonna Lily (Spathiphyllum sp.)
• Weeping Fig (Ficus benjamina)
• Dendrobium Orchid (Dendrobium sp.)
• Dumb Cane (Dieffenbachia var Exotica compacta)
• Ficus Alii (Ficus macleilandii var Alii)
• King of hearts (Homalomena wallisii)
• Lady palm (Rhapis excelsa)
• Lily turf (Liriope spicata).

sp - species; var - variety

Source: Dr. B. C. Wolverton, Eco-friendly House Plants, 1996.