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Thursday, Nov. 05, 2009

Dust mites are part of every day life

You’ve got dust mites. You do. Don’t deny it. They’re part of your life and, unless you live in one of those sealed sterile NASA laboratories, you come in contact with them all of the time. Fortunately, 95 percent of us aren’t bothered by them. For those who are allergic to them, their reactions range from sneezing to runny noses watery eyes — just generalized allergic reactions. People with asthma are particularly more vulnerable and can have much more severe reactions.

Dust mites can be found throughout the average house. The tiny (half the size of the period at the end of this sentence) creatures are everywhere — in your carpets, upholstered furniture and bedding, especially bedding. If you haven’t laundered your pillow, the feathers make up only 90 percent of its weight. The remaining 10 percent consists of dead skin (yours), mold, dung (theirs) and dead mites. Mattresses also play host to huge populations of dust mites.

The mites live off of you but not on you. They feed on your (or your pets’) shed skin. That’s why they love to hang around your bed. Your sloughed-off skin cells are steak and potatoes to these guys. Couple that with the warmth you give off as well as the 200 or so liters of moisture you lose each year during sleep, and you have a bunch of happy little mites.

It’s all of this eating that causes the problem. The average dust mite defecates 20 times a day. I haven’t been able to find out who it was that spent their work day staring into a microscope counting dust mite poop but it was probably a graduate student with a government grant. It’s their fecal droppings that, once dried out, cause the allergic reactions.

The cure for these mites is cleanliness. Regular vacuuming (at least twice a week) of carpets, draperies, furniture and mattresses will help to reduce the number of mites hanging around. But vacuuming can actually exacerbate the problem if it just puts the dust back into the air. So, make certain you change the bags often. Make certain you turn your mattresses very couple of months and vacuum thoroughly (or use a plastic covering).

Wash your sheets and pillow cases (and your pillows, if they’re washable) in hot water. If your pillows aren’t washable, throw them in the garbage.

And finally, don’t make your bed. Or at least, don’t make it until after lunch. When you make your bed, you’re sealing the mites in with the residual moisture you left behind when you got up. This allows them to remain in a relatively comfortable environment until you climb back in to bed. An unmade bed lets the dry air circulate and mites don’t like it if the humidity falls below 50 percent.

As always, if you have a question about pests, you can contact me through the Sun Herald.

Tim Lockley, a specialist in entomology, is retired from a 30-year career as a research scientist for the U.S. Department of Agriculture. To have him answer your individual questions, please send a stamped, self-addressed envelope to Tim Lockley, c/o Sun Herald, P.O. Box 4567, Biloxi, MS 39535.