Carpets – are they bad for your health?

Citation

Cooper, S. (2001), "Carpets – are they bad for your health?", Nutrition & Food Science, Vol. 31 No. 3. https://doi.org/10.1108/nfs.2001.01731caf.001

Carpets – are they bad for your health?

Carpets – are they bad for your health?

Why look at carpets?

The British love their carpets. They are found wall to wall in 98 per cent of UK households, far more than anywhere else in Europe. Only 16 per cent of French homes have them and 2 per cent of homes in Italy. Now more carpets are appearing in schools. With new funds currently available for schools refurbishment, the use of fitted carpets has been forecast to increase by 80 per cent in the next few years.

But can carpets ever be clean? The Healthy Flooring Network (HFN) thinks not. With asthma on the rise they believe it is now imperative to take a closer look at our indoor environment, and a leading allergy specialist agrees.

In July last year HFN asked Dr Jill Warner of the University of Southampton to investigate the role of carpets in asthma and allergies. Her report, a thorough review of published scientific literature, showed that carpets are a major source of allergens, which can both sensitise children and trigger asthma attacks in children who have been sensitised.

"Reducing allergen concentrations during infancy has the best chance of reducing the risk of asthma in later life", said Warner in her report, "Allergic diseases and the indoor environment". Since we spend 93 per cent of our time indoors, 5 per cent in traffic and only 2 per cent of time outdoors, reducing "the allergen load" in indoor environments has become imperative.

Allergens and asthma

Most experts agree that asthma and allergy are on the increase, particularly amongst children and teenagers. One in five children in the UK suffers asthma and it is getting worse. Last July the British Medical Journal revealed that asthma amongst adults had doubled in the last twenty years. While 30-40 years ago allergies were diagnosed in few people, now up to a third of the population in developed countries is affected by allergic disease.

There are multiple reasons for the rise. Parental smoking, diet and exposure to infection can trigger attacks, and outdoor traffic pollution is known to make asthma worse. But doctors know that to develop asthma and other allergies the sufferer must first be sensitised to one or several allergens. These include allergens from pets, dust mites, and moulds, at least two of which are lurking in our carpets.

Dr Warner's review showed that, by total amount, carpets contain much larger quantities of living mites and their allergens than bedding. In homes where there is asthma, covering mattresses, pillows and duvets with mite impermeable covers and regularly vacuuming beds are vital. What the new report showed was that treating beds alone is not enough. Carpets act as a magnet for mite and pet allergens and we need to do something about it.

One study showed that concentrations of dust mite allergens in the dust from carpets could be six to 14 times higher than that from smooth floors. In some homes this could be as high as that found in mattresses. If the house was also damp this was associated with even higher concentrations of allergens in carpet dust, where concentrations in smooth floor dust remained the same. "The presence of carpets in a home can dramatically increase the total mite allergen load compared to having smooth floors", said Dr Warner.

It seems, that our energy-conscious, tightly sealed homes with fitted carpets and upholstered furniture could be trapping allergen that previously would have been removed by ventilation through ill-fitting doors and windows.

What's in the dust?

Up to 100,000 dust mites can live in one square metre of carpet, feeding off the 1 gram of dead skin cells we produce every day. Each mite can lay up to 300 eggs during its lifetime of about three months. Their droppings build up as the carpet gets older and it is these which are the allergens.

Enzymes in the house mite droppings can actively damage the airways and interact with a body's immune system to cause an allergic sensitisation. Once sensitised, the chances of an individual developing asthma are greatly increased. Studies show a significant association between levels of exposure during infancy and the degree of sensitisation which occurs. Once sensitised, asthma can be triggered by repeat exposure. Among sensitised children 80 to 85 per cent of asthma is triggered by exposure to dust mites, the risk approximately doubling for every doubling of the level of exposure to mite allergens. And dust mites and their droppings have been linked not only to asthma, but also to other allergies including atopic dermatitis, seasonal conjunctivitis, and perennial rhinitis.

Pet allergens are another problem. The second most important trigger of asthma symptoms in the UK, they stick to carpets and other soft furnishings, even when there is no animal in the house. They are easily carried in on the clothes of visiting pet owners and accumulate in the soft furnishings and carpets. In sensitised children cat allergens will trigger asthma in 50 per cent; and dog allergens in 40 per cent. Even if they do not have a pet, their carpets will constantly expose them to the allergens they need to avoid!

For this reason, carpets are bad news in schools and nurseries. One New Zealand study found that the amount of cat allergen accumulated in carpets correlated with rates of cat ownership in the school. The average amount of allergen carried on the clothes of a cat owner was 6.1g compared to 0.72g on the clothes of a non-cat owning child, but smooth floors helped deal with it. Dust from non-carpeted areas of the school contained considerably less allergen than carpeted areas.

More than 50 per cent of time taken off school through chronic conditions is related to allergy and respiratory problems. HFN asks the question, "Could the floors children play and sit on be contributing to the problem?"

Can carpets be cleaned?

The report reviewed comprehensive testing on a range of cleaning methods including steam, vacuuming, and the use of chemicals and detergents. Vacuuming successfully reduced levels of pet allergens in the carpets but dust mites were more difficult to budge. Mites live right at the bottom of the carpet where it is dark and have suckers on their legs which attach to the fibres of the carpets. Vacuuming may collect the allergen but leave the mites to go on producing more.

None of the cleaning methods tested reduced allergen levels enough to alleviate asthma symptoms. The review looked at 20 trials. Only seven of these showed significant clinical improvements and all of these either removed carpets or subjected them to rigorous treatment that could only effectively be carried out in laboratories. One report showed that removing fitted carpets reduced the risk of asthma and allergies by up to 14 times.

Chemicals in floors

But it is not just allergens in the carpets that should be concerning us. Later research by HFN also showed that in an attempt to control the dust mites the carpet industry is adding chemicals to our carpets which are highly toxic and have been banned in other applications.

HFN commissioned independent laboratory analysis[1] of some of the most popular carpeting and vinyl (PVC) floors in order to expose high levels of hazardous chemicals used in their production. This analysis showed that both carpets and vinyl are loaded with chemicals that could escape into the indoor environment.

Most scandalous was the finding that both floorings contained an organotin, tributyl tin (TBT). TBT is known to cause a condition called "imposex" in populations of molluscs. In this condition females grow male sex organs and become sterile. Because of this its most common use – as an antifouling agent on ships' hulls – has been banned by the International Maritime Organisation. Now it is estimated that most of the TBT produced goes into the production of PVC. Carpets treated with Permafresh and Ultrafresh, a chemical treatment to kill off dust mites, contained high levels. As in the marine environment, it is highly likely that organotins leach out of PVC and carpets and into the home environment.

Among the carpet samples analysed HFN also found brominated flame retardants, formaldehyde and permethrin, a chemical added to Dynomite carpet treatment to kill dust mites.

Carpets can also "collect" toxic chemicals from the home environment, for example, fumes from paints, solvents and cleaning products used in the home, or residues from traffic pollution brought in on shoes. Once in the home these substances are likely to join the load of allergens in the reservoir that is the carpet.

Looking at vinyl

PVC, or vinyl, our favourite smooth flooring, is even worse – not only does it contain dangerous chemicals, but scientific studies have also shown that these chemicals escape into the indoor environment. Some of these chemicals have been linked to asthma.

Vinyl is the second favourite flooring in UK homes and schools, but few people buying it realise that it is created from a concoction of highly toxic chemicals. There is growing evidence that some of these, called phthalates, chemicals used to soften PVC, can contribute to allergic disease and other health problems. One Nordic study linked exposure to these chemicals to inflammation of the airways and increased risk of asthma.

Five vinyl flooring samples were analysed – from Marley Floors, B&Q, Gerflor Ltd, Armstrong, and Forbo Nairn. Three of the samples – Gerflor, Armstrong, and Forbo Nairn – contained very high levels of benzyl butyl phthalate (BBP). This finding was completely unexpected, since BBP is one of the phthalates causing most concern about its toxicity. DINP, another phthalate, was found in all of the samples. Both BBP and DINP have been banned from chewy children's toys because of their potential health effects. They constantly evaporate from vinyl flooring, are washed out during cleaning and can attach themselves to particles such as house dust. The analysis report says "Given the hazardous nature of these compounds, the levels of DINP and BBP … are clearly of concern".

Are schools aware?

Last summer HFN wrote to 147 local authorities asking for their policy on allergen-reduction and their attitudes to floors. The survey showed that reducing allergens in schools was not a priority. Only 35 authorities answered, despite two approaches, and few of them had any policy on allergen reduction, although more than half said that they would consider developing one. The majority preferred carpets and PVC because of cost, followed by safety and durability. Most authorities had no particular policy on carpets and PVC – despite some answering that they were aware of the health problems associated with these two floor-coverings. Although there was a fairly good awareness of the environmental and health problems of PVC, even those authorities who were replacing vinyl with linoleum were doing so only partially, with PVC still the favourite.

Many of the authorities said they passed the responsibility for decisions directly on to schools, and the survey clearly identified a need for stronger government guidance in this area. HFN has written to the Department of Health.

What can we do?

It is clear that we need to choose the least polluting floors. In a detailed Guide to Healthy Flooring HFN points out that lino, wood, rubber and other alternatives are just as hard wearing and easy to maintain as carpet and PVC but much less likely to accumulate allergens or contain high levels of chemical additives. It provides thorough and up-to-date information on a dozen alternative options and gives advice on how to safely remove carpets. It also provides a comprehensive list of suppliers. This guide is available free from HFN[2] to anyone wanting to actively reduce allergens in the indoor environment – whether in schools, at home, or at work.

What are the alternatives?

HFN acknowledges that there can be some health and environmental problems with other types of flooring but they believe that carpets and PVC are by far the worst. A range of alternatives exists, including:

• •

  Lino – very durable with an expected lifespan of 30-40 years. It is flexible, warm and a good sound absorber. Naturally anti-bacterial, it is also anti-static and easy to clean.

• •

  Cork – warm, rich looking and durable with excellent insulation and noise reduction qualities.

• •

  Coir, sisal, seagrass – natural grass floorings have excellent acoustic, thermal and anti-static qualities, which can be used as loose rugs.

• •

  Wood – very hard wearing and easy to clean. Choose reclaimed wood or wood from well-managed sustainable forestry schemes.

• •

  Laminates – are cheaper than wood and widely available from DIY stores. Some use glues containing formaldehyde – ask for low or zero emitting boards.

• •

  Stone and ceramic tiles – highly individual flooring which is cool in summer and very easy to clean.

• •

  Natural rubber – very durable and good shock and sound absorbers. This is particularly effective in commercial or public buildings.

Finally

Research continues into the complex problem of causes and triggers of allergic diseases, and currently no one knows all the answers. However, we spend most of our lives in indoor environments – in our homes, schools and workplaces. In these environments the floor has a major role to play. For those concerned about health, asthma and allergies and in the light of existing evidence the question is – are fitted carpets and vinyl worth the risk?

Sue CooperSue Cooper is a Spokesperson for The Healthy Flooring Network (HFN), an alliance of organisations and individuals concerned about health and the environment. A total of 19 organisations and individuals have signed a statement of concern. These include The Women's Environmental Network, Action against Allergy, the National Eczema Society, Friends of the Earth, The Migraine Action Association and The Association for Environment Conscious Building.

Notes

1. 1.

   Analysis of phthalates was carried out by the Laboratory of the Government Chemist, Teddington, Middlesex, UK, using a UKAS accredited method, LGC SOP OTH/C1-0015 (details provided on request). Organotin analysis was carried out by GALAB, D-21502 Geesthacht, Germany, using an accredited method (details available on request).

2. 2.

   For more information visit http://www.healthyflooring.org or contact the Healthy Flooring Network: e-mail: info@healthyflooring.org Helen Lynn, Health Coordinator at the Women's Environmental Network (WEN), is spokesperson for HFN. Telephone her on 020 7481 9004 or visit WEN's Web site: www.gn.apc.org/wen The HFN Guide to Healthy Flooring is on www.healthyflooring.org or send a large s.a.e. to the Women's Environmental Network (WEN), PO Box 30626, London E1 1TZ.