Carpet can reduce noise, add comfort and warmth, and provide a soft surface for young children to crawl and play on. However, few people realize that our favourite flooring also comes with a number of significant health risks.
Carpets are a major source of toxic chemicals in the home, typically containing well over 100 chemicals in its fibre-bonding material, dyes, backing glues, fire retardant, latex binder, fungicide, and antistatic and stain-resistant treatments. These can 'outgas' for weeks-even years-after installation. Formaldehyde, toluene, xylene, styrene, benzene, 4-phenylcyclohexene and methyl-benzene-known as 'volatile organic compounds' (VOCs)-are just a few of the nasties that may be lurking beneath your feet and in the air around you.
Carpets also act as sinks for dustmites, heavy metals, pesticides, cigarette smoke, moulds and other pollutants. These aren't completely removed by routine cleaning and may easily be inhaled by the whole family (Townsend Lett, 2001; 215: 28-30).
Research now suggests that toxic carpeting may be responsible for an array of health problems-from asthma and allergies to cancer and neuropsychiatric disorders.
According to US environmental group the Washington Toxics Coali-tion, there have been hundreds-maybe even thousands-of instances where people became ill after new carpeting was installed. In the 1990s, the US Consumer Product Safety Commission (CPSC) received more than 6000 such complaints (Townsend Lett, 2001; 217: 172-4), with symptoms such as eye, nose and throat irrita-tion, rash and fatigue. Around half of the sufferers had never experienced an allergy before.
Ironically, in 1987, some of the most adverse reactions were seen in the heart of the US Environmental Protection Agency (EPA), when over 1000 employees complained of symptoms after new carpeting was installed in their headquarters. Although the agency publicly denied any link between symptoms and the new flooring, over 25,000 square yards of carpet were removed three and a half years later.
In 1992, in response to public concerns, the carpet industry launched the 'Green Label' certifi-cation programme, a PR initiative to reduce VOCs in its products. However, only a scant handful of chemicals are measured and only a few carpets are tested. So, a Green Label is still not a guarantee of a carpet that will not cause health problems.
In fact, one family in Maryland was disabled after installing Green Label carpeting in their store. A sample of the carpet caused gross nervous-system abnormalities in mice (Townsend Lett, 2001; 217: 172-4).
Toxic carpets are also a concern in the UK. In 2001, a joint report from the Healthy Flooring Network and Greenpeace found surprisingly high levels of hazardous chemicals in carpets purchased on the high street (www.healthyflooring.org/reports.html).
Lab analyses revealed that some carpets contain significant amounts of the hormone-disrupting flame-retardant BDE-209, the pesticides permethrin (implicated in Gulf War syndrome) and tributyltin (TBT, toxic to the immune and reproductive sys-tems), and formaldehyde.
Studies of carpet installers show that they have an increased risk for leukaemia, and testicular, bowel, oral and pharyngeal cancers (Am J Ind Med, 1988; 14: 15-24; Gastroenterology, 1978; 75: 221-3; Epidemiology, 1992; 3: 300-9). Other research reveals that carpetlayers exposed to solvents, such as glues and adhesives, are at an increased risk of neuropsychiatric disorders-and the greater the exposure (years on the job), the greater the risk (Scand J Work Environ Health, 1976; 2: 14-20). Flooring workers exposed to solvents for the longest periods of time showed the greatest decline in visual memory, perceptual speed and attention, and visuospatial skill (Occup Environ Med, 2002; 59: 49-57). The central nervous system appears tobe particularly sensitive to the toxic effects of carpet chemicals (Br J Ind Med, 1986; 43: 101-6).
In the 1990s, the Anderson Lab in Massachusetts extensively tested carpet samples-with alarming results. Mice exposed to air passing over a piece of carpet heated to about 37 degrees C-equivalent to sun exposure, heating ducts or radiantly heated floors-developed "severe neurological and/or neuro-muscular toxicity". One carpet caused severe convulsions after the second hour of exposure, and some mice even died. Other mice had sensory and pulmonary irritation (J Nutr Environ Med, 1995; 5: 375-86) and, on autopsy, lesions of the brain and liver, as well as kidney degeneration (Townsend Lett, 2001; 217: 172-4).
Although these results may not necessarily apply to humans, the carpet-exposed mice also developed hypersensitivity pneumonitis, as did a patient exposed to the identical carpet (Townsend Lett, 2001; 217: 172-4). Other respiratory and neurological symptoms seen in the mice have been reported by carpet owners (J Nutr Environ Med, 1997; 7: 177-86).
The Anderson Lab's findings have been confirmed by EPA researchers and Dr Yves Alarie, at the University of Pittsburgh, who was hired by the US Carpet and Rug Institute (CRI). Nevertheless, both the EPA and CRI publicly denied any health effects.
Carpets are a reservoir for a host of other pollutants-from dustmites and animal dander to moulds and pesticides. Along with other textiles in the home, they act like sponges, absorbing airborne particles and fumes from paint, cleaning products and synthetic fragrances, and releasing them back into the air over time (Environ Sci Technol, 2000; 34: 4193- 8). Shoes bring in dust, particles and pesticides, depositing them onto the carpet. The deeper the pile, the greater the area for toxins to collect. Alarmingly, pesticides and other out-door organic pollutants may be 10 to 100 times higher in carpet dust than in the surrounding outdoor soil (Environ Health Perspect, 1999; 107: A352-7).
Cleaning alone isn't enough. Dust-mites lie deep within carpet fibres, while chemicals can migrate into the padding below. Shampooing can make things worse, as damp or wet carpet becomes the perfect breeding ground for moulds to grow.
Children are especially at risk from the pollutants in carpets, mainly because they play and crawl on carpets for hours at a time. As their immune systems are not fully developed, this means they are even more susceptible to toxic exposures (Townsend Lett, 2001; 215: 28-30).
People with asthma and allergies are another vulnerable group. As well as triggering symptoms, pollutants found in carpets may also cause the onset of the condition. In one study, synthetic carpeting was significantly associated with the development of asthma, wheezing and allergy in nearly 6000 Russian schoolchildren (Am J Public Health, 2004; 94: 560-2). Researchers at UK's University of Birmingham found a link between wall-to-wall carpeting-and, espec-ially, mouldy carpets-in the work-place and adult-onset asthma (Am J Epidemiol, 2006; 164: 742-9).
Clearly, although carpet may be the cozier choice, it is certainly not the healthiest.
Experts agree that the best floors, in terms of health, are of wood, tile or other hard surfaces (www.watoxics.org/ files/carpet-fact-sheet). However, avoid vinyl (PVC), another source of toxic substances (www.healthyflooring.org).
Area rugs are a good option as they can be removed from time to time for a thorough cleaning. Tight-weave rugs made of jute or natural grass are ideal.As for alternative carpeting, an excellent choice is wool that is stitched, not glued, to its backing and not treated with a stainguard or pesticides. Never glue carpets to the floor, but use hook-and-loop installa-tion (fastening strips) instead. If glue is the only option, then use a low-emitting adhesive that contains less that 5-per-cent solvent (Townsend Lett, 2001; 217: 172-4).
Whatever the type of carpet-and underlay-you choose, ask to see its emission-test results from the retail-er or manufacturer. Also, request that the carpet be unrolled and aired out for a few days prior to delivery. During installation-and for up to a week afterwards-keep the room well ventilated.
By taking these steps and ensuring that your carpet is kept as clean as possible (see box, page 20), you can keep your exposure to hazardous chemicals to a minimum.
For a list of alternative flooring suppliers, see www.healthyflooring.org/suppliers .
Keeping carpets safe
- Use doormats at entrances, which can reduce pesticide residues on carpets by 25 per cent, and total carpet dust residues by 33 per cent (www.watoxics.org/files/carpet-fact-sheet).
- Take your shoes off to avoid tracking in pesticides and other chemicals from outdoors.
- Vacuum your carpet frequently with a high-efficiency filtration system (HEPA) or use a central vacuum system that exhausts to outside of the building. For deeper cleaning, use hot-water extraction methods.
- Prevent mould growth by making sure that cleaned carpets are dry within 24 hours. Provide plenty of ventilation so that the moisture evaporates into the air. Soaked carpeting due to, say, flooding, should be professionally cleaned and dried within 24 hours, or replaced. Always replace carpet damaged by biologically contaminated water such as sewage.
- Keep indoor humidity levels low to decrease dust mites and mould growth.
- Use disposable damp cloths for dusting and mopping.
- Keep chemical contamination in the home to a minimum by using low-VOC paints and other materials, as well as non-toxic cleaning agents. WDDTY's Your Healthy House is a useful guide, or subscribe to PROOF! (www.proof.co.uk) for specific product reviews.
What's beneath your feet?
Here are just a few of the hundreds of chemicals that may be found in carpet:
- Formaldehyde. Concentrations above 0.01 ppm (parts per million) may cause burning eyes, headache, tightness in chest, asthma attacks, depression and even death (Townsend Lett, 2001; 215: 28-30). Exposure also increases the risk of several cancers, including of the lung, throat and nose.
- Styrene. Classified as a probable human carcinogen by the International Agency for Research on Cancer (IARC), this agent can cause skin, eye and respiratory irritation as well as damage to the liver, reproductive system and central nervous system.
- Benzene. Chronic exposure to even relatively low levels causes eye, nose and throat irritation, headaches, loss of appetite, loss of coordination, drowsiness and psychological disturbances. In animals, inhaling benzene leads to cataracts, blood disorders, and lymphatic and bone marrow diseases such as leukaemia. Some studies found it to cause cancer, birth defects and DNA mutations.
- Pesticides. The effects depend on the chemical constituents but, in general, they include cancer, fetal damage, liver and nerve damage, skin problems, and irritation to the eyes and respiratory system.