| By Ed Crawford If you could take a close look at the carpet you're cleaning, you might be
surprised at what you'd find. Out of sight and harmless to most of us, microscopic herds
of dust mites live deep in carpet fibers and
may number in the millions.
Facility managers and contract cleaners -- at least
who clean buildings or homes that have tenants or residents who are allergic to indoor
allergens -- need to know how to combat these unseen pests to keep the indoor environment
as allergen-free as possible.
Dust mites
are linked with dust allergies and have caused significant health problems. Humans are not
allergic to mites but to the protein in their fecal pellets and the body parts of dead
mites, which are small enough to become airborne. Approximately 70 percent of people who
have house dust allergies are sensitive to "mite components" in airborne dust.
Dust mites
are less than 1/2 millimeter long (approximately 10 could fit on the period at the end of
this sentence). Mites belong to the same family as ticks and spiders. Hundreds of
different species are found in nearly every habitat of animal and plant life.
House dust mites
live in bed mattresses, carpeting and soft or upholstered furniture. They seek these
protected environments and are rarely found in other parts of a building or residence.
Water To Grow
Dust mite
population levels are normally determined by humidity in a building. Mites require
moisture in their environment, and it is the most important factor in determining their
survival and growth.
A humidity level of 65 to 75 percent and
temperatures between 72 and 79 degrees Fahrenheit are optimum conditions for dust mite survival. Mite population densities rise
and fall with natural seasonal changes in relative humidity and temperature.
In buildings -- where it never rains -- dust mites
are living in a veritable desert and are under a constant threat of dying of thirst.
Because they cannot find liquid water in indoor environments, their food has to be moist
enough to provide them with the minimum water required for survival.
Dust mites
feed on microscopic fragments of human skin cells, and fungi and bacteria. Because each of
us sheds approximately 50 million skin cells a day, dust mites have an abundant food
supply.
They have a life span of 40 to 60 days, and in
vacuum bags -- which are stocked with ample dust mite food -- they can breed for hundreds
of generations. Unless you have high filtration (capable of filtering particles between 1
and 5 microns) on your vacuum bag, dust mites that are vacuumed up from carpets will be
emitted back into the air and into carpeting.
Many people are affected by dust mites, and
everyone has some kind of reaction to dust. This is a significant concern to building
occupants and should prompt you to develop a routine preventive maintenance program.
This will depend on the concentration of people in
the facility and the use and condition of the building. Daily and weekly dusting,
vacuuming and cleaning of upholstered furnishings or carpeted flooring -- combined with
periodic carpet pre-conditioning, shampooing and/or extraction -- should be performed.
Installing inside and outside entry mats will also
help reduce the amount of dirt particles that enter the building, which cause soiling of
carpet fibers and higher levels of dust in the air. Applying a preventive maintenance
program will help control household dust and mites that inhabit our homes, diminish indoor
air quality and contribute to allergies.
Ed Crawford is president of Core Products Co.,
Inc., in Canton, TX.
Copyright National Trade Publications, Inc. |
