Carpet and Allergies

Carpet Does Not Exacerbate Allergies

Allergists routinely recommend carpet removal due to allergy concerns based on an allergen avoidance theory. Allergists believe that if all possible places where allergen can be held are eliminated, allergic reactions will disappear.  However, the removal of carpet has never produced a reduction in allergic reactions.  The incidence of allergy sufferers that use carpet is about the same as for those who avoid carpet. Numerous studies have been performed in cultures that do not use carpet and allergy rates per capita are very similar to the U.S culture where heavy carpet use is the norm.

In 1973, based on anecdotal evidence that carpet contributed to allergic reactions, the Swedish government banned the used of carpet in all public facilities.  Carpet was replaced with hard surface flooring materials in homes, commercial environments, government buildings, and carpet market share fell from approximately 20% of the market share to less than 2% of the total flooring market share.  Follow-up studies by the Swedish Central Statistics Bureau indicated a dramatic increase in reported allergies by the Swedish population following carpet replacement. As carpet was removed and hard surface flooring was installed, the incidence of allergy increased among the Swedish population. This alarming increase was in direct proportion to the amount of hard flooring materials installed. This ban was removed after 17 years when the dramatic increase in allergic reactions was confirmed.

Most of the mite allergen in the home can be found in pillows, mattresses, or upholstered furniture.  In fact, 30% of the weight of the average pillow is comprised of dead human skin scales (dust mite food source) and dust mite allergen.  The average mattress can weigh as much as 100 pounds more than when originally purchased due to the accumulation of the matter.  While carpet is typically mentioned in connection with allergies, pillow and mattress accumulations of these allergens pose a far greater exposure risk.

Regular Cleaning Greatly Reduces Allergens

Recent investigations show that carpet cleaning reduces the amount of mite allergen in carpet by more than 90% with each cleaning.  Dust mites tend to have seasons in which they proliferate.  Due to elevated humidity, dust mite populations tend to increase during the spring and summer and the population diminishes during the heating season when the air becomes much drier.  By scheduling carpet cleaning in bedrooms, media rooms, or other rooms, where time is spent on the floor, during September and October, allergen can effectively be removed before accumulation of allergen becomes an exposure risk.

In addition to regular cleaning, new treatments have become available which have been proven to be effective in eradicating dust mites.  Some products containing benzyl benzoate have received mixed scientific reviews relating to their efficacy.  To date, the most effective product brought to market is a product produced by The Ecology Works ( http://www.dustmitex.com/). This EPA registered product, (Dust Mite Control) can be added to the rinse water during cleaning and applied during the carpet cleaning process, or it may be applied as a separate treatment on a regular basis to prevent the accumulation of dust mite populations and their associated allergen.

It also must be noted that even though all carpet is characterized under one classification, there are numerous qualities of carpet with numerous construction characteristics.  Residential carpet is very different from commercial carpet in its release characteristics.  Loose constructions, have the tendency to release far more contaminants than tighter constructions.

For any flooring surface, effective maintenance and utilizing the philosophy of cleaning for health is a primary element in ensuring occupant wellness. Carpet acts as a trap for airborne allergen.  Once allergen becomes trapped within the pile of the carpet, it must be removed.  Without carpet to act as a filter, allergen tends to remain airborne or may become airborne with each footstep.  Studies reveal carpet is very effective in trapping this allergen without releasing it into the breathing zone.  Carpet cleaning has proven to be very effective in extracting this allergen and removing it from the indoor environment.  A good common sense approach for people with allergies is to install carpet and perform regular cleaning to remove the allergen.

Carpet is a Good Choice for Those With Allergies

In comparing the allergen removal efficiency of carpet and wood or tile flooring, allergen removal is much more effective with carpet than with hard surfaces.  Vacuuming of hard surfaces can be initiated as an effective extraction tool, but vacuuming of hard floors is rarely performed.

 Long-term studies have shown that proper carpet selection, along with an adequate maintenance program, can reduce the amount of allergen in carpet and provide a suitable living environment.  In one such study, dust mite allergen levels in carpet were significantly reduced over the course of one year.  The study involved 12-year old carpet that had received neglectful maintenance.  Despite heavy concentrations of mite allergen, levels were continually reduced over the course of the study.  Hot water extraction alone produced a 92% reduction, while vacuuming continued to reduce allergen levels on a daily basis.  No airborne dust mite allergen was detected during the two-year study.  This study was performed using regular maintenance only. 

Allergens can found in any environment.  The presence of allergen on any surface does not necessarily identify a source of allergens or a cause for allergic reactions.  The ability to remove these allergens or a flooring surface’s ability to contain these allergens without releasing them into the breathing zone should be the primary factor in choosing floor covering material.  Carpet can fulfill these requirements by providing a surface that absorbs airborne allergen without releasing them into the breathing zone and provides construction characteristics that allows for effective removal as a result of routine maintenance.  

Key Points to Consider

• The replacement of carpet with a smooth flooring surface does not produce the results expected by allergy patients.

• Allergy rates per capita in cultures that do not use carpet are very similar to the U.S. culture where heavy carpet use is the norm.