Published in East West, July 1989, p.55.
by John Bower (copyright 1989)

Wall to wall carpeting is found in virtually every house in the country. It is no longer an option that builders offer, it is a requirement. If a contractor were to build houses without carpeting, he would soon be out of business because we, as consumers, demand the plush, expensive look of wall to wall carpeting in our homes and apartments. Not content with having carpeting in only the living room, we often demand it in all of the rooms, including the bathroom and kitchen.

Builders like to use carpeting instead of alternatives such as hardwood or ceramic tile because it can be less expensive to buy and install. For them, the bottom line is cost and saleability. The high cost of housing is also an obvious concern to home buyers. When considering a new home, either to buy or to rent, the consumer often considers cost first. Other important concerns will be neighbourhood, square footage, floor plan, style, number of bedrooms, bathrooms, etc. Unfortunately, healthfulness is rarely a consideration.

Most modern building materials have some negative effects on health. As a result, our homes are often the cause of various illnesses and symptoms. Carpeting is a material that can adversely affect us in several different ways. When new, it can outgas toxic fumes into the air. As it ages, it can disintegrate, polluting the air with synthetic particles. It can also be a haven for micro-organisms to grow in. Wall to wall carpeting simply cannot be cleaned sufficiently to make it non-polluting. When cleaning up a house or apartment to reduce indoor pollution, carpeting should be one of the first things to be removed.

OUT GASSING

Most new carpeting is made of synthetic fibres. Generally these fibres are derived from petroleum. During the manufacturing process, crude oil is transformed into a polymer such as polypropylene or nylon. The raw polymer is then spun into fibres and attached to a backing to create carpeting. Sometimes the fibres are chemically treated to render them stain or fire resistant. They may also be treated with fungicides or pesticides.

The raw fibres themselves, and all of the chemical treatments can outgas various fumes into the air. Out gassing refers to the odours that are released by a substance. When you notice the smell of a new car's interior, you are noticing the chemicals out gassed by the synthetic materials. Often, these out gassed chemicals are carcinogens, sensitizers or irritants. NASA is so concerned with the negative effects of the chemicals out gassed by synthetic materials that they have tested virtually everything that goes into a spacecraft. Only materials that have minimal out gassing characteristics can be used inside the tightly closed environment that astronauts must live in. The carpeting that we put in our houses would fail NASA's requirements miserably.

New synthetic carpeting has been shown to outgas many different chemicals into the air that we breathe. Some have not been tested for their health effects. Of the chemicals that have been tested, several are very hazardous. Formaldehyde is a respiratory irritant and a potential carcinogen. It has been found to sensitize people to other chemicals, so they begin to react to smaller and smaller exposures. Ethylbenzene is highly irritating to the eyes. Toluene, xylene, and styrene can have a narcotic effect. Other chemicals that can be out gassed by new carpeting include tetrachloroethylene, acetonitrile, azulene, benzene, diphenyl ether, dodecane, etc., etc. Actually there are dozens of different chemicals that can be present, and their names resemble alphabet soup more than indoor air pollutants. Many people are so acutely sensitive to some of these chemicals that their eyes immediately begin to water and their sinuses clamp shut when they are around new carpeting. Even though we experience no immediate symptoms, we may still be affected. These are potentially dangerous pollutants and living beings should not be exposed to them, even in low concentrations, if it can be helped.

Most carpeting is installed over a pad of some type which has its own out gassing characteristics. If a glue or adhesive has been used, it too is capable of out gassing. Usually, the flooring underneath carpeting is a man-made wood product such as plywood, MDF or particle board. These can all contribute to the air pollution by releasing formaldehyde as a result of the glue used in their construction.

Out gassing will decrease with time. Usually after four or five weeks, the pollutant levels will be greatly reduced. They may not be eliminated entirely, but the danger is considerably lessened. Of course, if someone has been exposed to the higher levels continuously during the initial period of out gassing, they may have become sensitized, meaning that they will now react to much lower levels. Some people have been forced to abandon their home once becoming hypersensitive to the out gassed chemicals. If carpeting has not been correctly manufactured, it may be defective and have an extended out gassing period, lasting many weeks.

There are a few manufacturers who make natural fibre carpeting out of 100% wool or cotton. Often these products have a strong odour themselves because of a potentially toxic dye, or chemical treatment. Wool carpet is usually mothproofed. The chemical used is not only dangerous to moths, but there are sensitive people who are bothered by it as well.

Even with very old carpeting, having virtually no out gassing characteristics, there are other reasons to avoid this common product.

SYNTHETIC HOUSE DUST

There are many people who are allergic to house dust. House dust can be composed of a wide variety of materials. We all shed a little bit of dead skin each day. Pets also shed bits of skin that have their own particular allergic potential. As synthetic materials age they can become brittle and begin to decompose, contributing to house dust. Sunlight passing through a window onto the carpeting will hasten this deterioration. As the tiny bits of carpeting break off, they contribute to the house dust floating around in the air.

Synthetic house dust can irritate the sinuses and respiratory tract like any other type of dust. It can cause some other problems as well. As it is pulled through the ductwork of the heating system, it will come in contact with the high temperatures inside the furnace. This results in it being burned. When synthetic materials are burned, they give off a variety of toxic fumes. When firemen enter a burning building, they routinely wear oxygen masks to protect them from these noxious gases. Breathing any type of smoke is harmful, but smoke from synthetic materials is even worse, containing gases such as phosgene and cyanide. Of course, as the minute synthetic particles are burned inside the furnace, the concentrations of gases will be considerably less than those to which firemen are exposed in a fire. However, long term exposure to low levels of these chemical cannot do anyone any good.

MICRO-ORGANISMS

Carpeting is a reservoir for all kinds of house dust as well as food particles. The dust mite is a micro-organism that often lives in carpeting. It can thrive on the nourishment found there. Bacteria, moulds, yeasts, and other organisms can also grow and multiply in carpeting. Most of these micro-organisms will flourish if the humidity is high. If the carpeting is located in areas where there can be a lot of moisture, it will be even more likely to harbour these microscopic creatures. Kitchens, bathrooms and laundry areas are very vulnerable.

If carpeting is attached to a concrete slab that is in contact with the earth, it can have a micro-climate of higher relative humidity than the rest of the room. This is because the concrete slab will be slightly cooler than the rest of the room. In any area where the temperature is lower, there will be a zone of higher relative humidity. This is why moisture often forms on a window in the winter. The window is colder than the rest of the room, and the relative humidity rises to the point that it reaches 100% and condenses on the glass.

If a concrete slab was constructed without a vapour barrier beneath it, moisture can migrate up from the ground through the concrete, adding humidity to the carpet that the micro-organisms will thrive on.

Scientific studies have measured ten million micro-organisms per square foot in carpeting. This has been described as a "sea of micro-organisms." When moving across carpeting, you can imagine a cloud of living creatures being disrupted with each step. For an adult, this cloud will be several feet below nose level, but for children playing on carpeting the effect will be much more severe. A child allergic to mould or dust mites should never play on carpeting. Other children should avoid playing on carpeting in order not to be sensitized to these allergens.

CLEANING

It is often believed that a good vacuuming or shampooing will alleviate any problems with carpeting. Unfortunately, this is not the case. In fact, it will often aggravate the problem. Shampooing or steam cleaning has little effect on the out gassing characteristics of carpeting because most of the chemicals involved are not water soluble. Some shampoos and cleaning products contain pesticides to which many sensitive people react. Anyone who has used a water/vacuum cleaning machine will attest to the fact that unbelievable quantities of filthy water will need to be disposed of. If the cleaning wand has a transparent head, you can watch the dirt being sucked out of the carpeting. Usually, there is so much in the way of dirt, house dust, and micro-organisms in carpeting that it is virtually impossible to remove it all. Passing a water/vacuum cleaning wand back and forth over the same spot will continually remove debris, but as is usually the case, the water never seems to run clean. Carpeting has a tremendous reservoir capacity containing many pounds of undesirable filth. A much more effective cleaning technique would be to take the carpet outdoors, hang it over a line, and beat it. This is certainly not possible with most large wall to wall carpet installations. However, it is effective with throw rugs, Oriental carpets, or Navajo rugs.

Cleaning procedures that result in damp carpeting can actually cause the various micro-organisms to thrive, resulting in more life than before the cleaning. One report in a medical journal found an unusually high incidence of Kawasaki syndrome in eastern Colorado following the shampooing of carpeting. This is an acute, systemic illness characterized by fever that occurs predominately in children under age five. While the cause of Kawasaki syndrome is unknown, it has been suggested that shampooing carpeting may be a risk factor. Routine vacuuming has been shown to have little effect on the numbers of micro-organisms found in carpeting. In fact, sometimes the numbers can actually be higher after vacuuming than before. This is because the vacuum simply pulls the organisms up from the padding into the higher layers of the carpeting. Most portable vacuum cleaners have very inefficient filters that allow dust to pass through and be dispersed back into the room. Built-in central vacuum systems with an outdoor exhaust will minimize this problem.

SUMMARY

Carpeting is one of the most un-healthy materials found in houses today. It outgases toxic chemicals directly into the air. It releases more toxic chemicals when small bits of it are burned by the furnace. This, combined with the tremendous quantity of micro-organisms in carpeting and the fact that it is virtually impossible to clean make it a poor choice in a healthfully constructed house.

Hardwood flooring, ceramic tile, and even coloured concrete make much healthier alternatives. While hardwood or ceramic tile may cost more initially, they will last considerably longer than carpeting, making them more cost effective. Their appearance can be enhanced with the use of natural fibre rugs that can be easily removed for the occasional beating.

When considering the added cost of healthful building materials, one should also consider the added cost of health care if unhealthy materials are used. A few extra dollars added to a mortgage payment is always preferable to the cost of visiting an allergist every month. The cost of ill health can be very high, often exceeding that of the mortgage payment. It only makes economic sense to build a house with healthful materials. It will be good for your pocketbook as well as improve your well being.