The Biology of
Household Dust
Today's
Snack: You'd better have it before you look at the picture that goes with
today's exercise. For snack, crush a few graham crackers into "dust" and let
your mouth be the human vacuum!
--------------------
One stick of butter or margarine
Dustcloths
Magnifying glass
Almost every home has dust. But once you know
what's in it - things that are ALIVE, or used to be - maybe you'll be better
about helping out doing the dusting so that you can put a little more separation
between yourself and the Creatures of the Dust.
House dust mites are found in most homes.
They are microscopic, eight-legged creatures closely associated with us, but
they are not parasitic and do not bite. They don't burrow under the skin, like
scabies mites or live in skin follicles, like skin follicle mites. Dust mites
go from being an egg to being an adult in just three or four weeks, so you can
see how they can accumulate quickly as their "generations" are spaced so
closely together.
The concern about dust mites is people are
allergic to them. Symptoms associated with dust mite allergies include
sneezing, itchy, watery eyes, nasal stuffiness, runny nose, stuffy ears,
respiratory problems, eczema and (in severe cases) asthma.
Many people notice these symptoms when they
stir dust during cleaning activities. But, dust also contains other allergens,
including cat and dog dander, cigarette ash, cockroach droppings, mold spores
and pollen.
How can you find out if you're allergic to
dust mites? An allergist, a medical doctor specially trained to treat
allergies, should be consulted for proper diagnosis.
The dust mite allergen is their tiny feces
and body fragments which are components of dust. These particles are so small
they can become airborne and inhaled when dust is disturbed.
House Dust Mite (highly magnified)
How can you make your home not very friendly
to dust mites, so they won't live there? Keep it cool and humid. To thrive,
dust mites need very warm temperatures (75-80 degrees F) and high humidity
levels -- 70-80 percent relative humidity. One study showed when humidity is 60
percent or lower, the mite population stops growing and dies out. Another one
showed that if you use an electric blanket, the dust mites will disappear,
since that's a dry warmth, and they like a more humid warmth.
Humans continually shed skin and lose about
1/5 ounce of dead skin each week. To find out how much that is, look at a
4-ounce stick of butter or margarine. About one-fourth of that stick, or 2
tablespoons, makes an ounce. Look at the size of the chunk that one ounce of
butter is. Over five weeks' time, you will lose about that much dead skin.
Ewwwwww!
But be glad you do: out with the old to make
room for the new.
Here's where the dust mites come in: we spend
about one-third of our lives sleeping, and that's when a lot of our dead skin
sloughs off. So high levels of dust mites are often associated with the bedroom,
especially bedding and the mattress. Dust mites also eat animal dander so
allergens will be plentiful in areas where family pets sleep.
What's the answer? Wash your sheets once a
week! And launder your pet's blanket or rug! Don't let your pet sleep on your
bed. When you dust furniture, use a little liquid product so you're not just
moving the dry dust around from place to place. Vacuum floors and furniture
regularly.
Now take dust cloths and go out and find
yourself some dust. Then look at it with a magnifying glass. Can you identify
any of these common "ingredients" in dust?
Cigarette
ash
Incinerator
ash
Wool,
cotton, paper and silk fibers
Fingernail
filings
Food
crumbs
Glass
particles
Glue
Graphite
Animal
and human hair
Insect
fragments
Paint
chips
Plant
parts
Pollen
Polymer
foam particles
Salt
and sugar crystals
Human
skin scales
Animal
dander
Soil
Fungal
spores
Tobacco
Wood
shavings
